#include "prologue-value.h"
#include "target-descriptions.h"
#include "user-regs.h"
+#include "observer.h"
#include "arm-tdep.h"
#include "gdb/sim-arm.h"
#include "vec.h"
#include "features/arm-with-m.c"
+#include "features/arm-with-iwmmxt.c"
+#include "features/arm-with-vfpv2.c"
+#include "features/arm-with-vfpv3.c"
+#include "features/arm-with-neon.c"
static int arm_debug;
static const char *arm_fallback_mode_string = "auto";
static const char *arm_force_mode_string = "auto";
+/* Internal override of the execution mode. -1 means no override,
+ 0 means override to ARM mode, 1 means override to Thumb mode.
+ The effect is the same as if arm_force_mode has been set by the
+ user (except the internal override has precedence over a user's
+ arm_force_mode override). */
+static int arm_override_mode = -1;
+
/* Number of different reg name sets (options). */
static int num_disassembly_options;
static void convert_to_extended (const struct floatformat *, void *,
const void *, int);
-static void arm_neon_quad_read (struct gdbarch *gdbarch,
- struct regcache *regcache,
- int regnum, gdb_byte *buf);
+static enum register_status arm_neon_quad_read (struct gdbarch *gdbarch,
+ struct regcache *regcache,
+ int regnum, gdb_byte *buf);
static void arm_neon_quad_write (struct gdbarch *gdbarch,
struct regcache *regcache,
int regnum, const gdb_byte *buf);
+static int thumb_insn_size (unsigned short inst1);
+
struct arm_prologue_cache
{
/* The stack pointer at the time this frame was created; i.e. the
/* Return the bit mask in ARM_PS_REGNUM that indicates Thumb mode. */
-static int
+int
arm_psr_thumb_bit (struct gdbarch *gdbarch)
{
if (gdbarch_tdep (gdbarch)->is_m)
return 0;
}
-static CORE_ADDR arm_get_next_pc_raw (struct frame_info *frame,
- CORE_ADDR pc, int insert_bkpt);
-
/* Determine if the program counter specified in MEMADDR is in a Thumb
function. This function should be called for addresses unrelated to
any executing frame; otherwise, prefer arm_frame_is_thumb. */
-static int
+int
arm_pc_is_thumb (struct gdbarch *gdbarch, CORE_ADDR memaddr)
{
struct obj_section *sec;
struct minimal_symbol *sym;
char type;
+ struct displaced_step_closure* dsc
+ = get_displaced_step_closure_by_addr(memaddr);
+
+ /* If checking the mode of displaced instruction in copy area, the mode
+ should be determined by instruction on the original address. */
+ if (dsc)
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: check mode of %.8lx instead of %.8lx\n",
+ (unsigned long) dsc->insn_addr,
+ (unsigned long) memaddr);
+ memaddr = dsc->insn_addr;
+ }
/* If bit 0 of the address is set, assume this is a Thumb address. */
if (IS_THUMB_ADDR (memaddr))
return 1;
+ /* Respect internal mode override if active. */
+ if (arm_override_mode != -1)
+ return arm_override_mode;
+
/* If the user wants to override the symbol table, let him. */
if (strcmp (arm_force_mode_string, "arm") == 0)
return 0;
target, then trust the current value of $cpsr. This lets
"display/i $pc" always show the correct mode (though if there is
a symbol table we will not reach here, so it still may not be
- displayed in the mode it will be executed).
-
- As a further heuristic if we detect that we are doing a single-step we
- see what state executing the current instruction ends up with us being
- in. */
+ displayed in the mode it will be executed). */
if (target_has_registers)
- {
- struct frame_info *current_frame = get_current_frame ();
- CORE_ADDR current_pc = get_frame_pc (current_frame);
- int is_thumb = arm_frame_is_thumb (current_frame);
- CORE_ADDR next_pc;
- if (memaddr == current_pc)
- return is_thumb;
- else
- {
- struct gdbarch *gdbarch = get_frame_arch (current_frame);
- next_pc = arm_get_next_pc_raw (current_frame, current_pc, FALSE);
- if (memaddr == gdbarch_addr_bits_remove (gdbarch, next_pc))
- return IS_THUMB_ADDR (next_pc);
- else
- return is_thumb;
- }
- }
+ return arm_frame_is_thumb (get_current_frame ());
/* Otherwise we're out of luck; we assume ARM. */
return 0;
}
/* Return 1 if PC is the start of a compiler helper function which
- can be safely ignored during prologue skipping. */
+ can be safely ignored during prologue skipping. IS_THUMB is true
+ if the function is known to be a Thumb function due to the way it
+ is being called. */
static int
-skip_prologue_function (CORE_ADDR pc)
+skip_prologue_function (struct gdbarch *gdbarch, CORE_ADDR pc, int is_thumb)
{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
struct minimal_symbol *msym;
- const char *name;
msym = lookup_minimal_symbol_by_pc (pc);
- if (msym == NULL || SYMBOL_VALUE_ADDRESS (msym) != pc)
- return 0;
+ if (msym != NULL
+ && SYMBOL_VALUE_ADDRESS (msym) == pc
+ && SYMBOL_LINKAGE_NAME (msym) != NULL)
+ {
+ const char *name = SYMBOL_LINKAGE_NAME (msym);
- name = SYMBOL_LINKAGE_NAME (msym);
- if (name == NULL)
- return 0;
+ /* The GNU linker's Thumb call stub to foo is named
+ __foo_from_thumb. */
+ if (strstr (name, "_from_thumb") != NULL)
+ name += 2;
- /* The GNU linker's Thumb call stub to foo is named
- __foo_from_thumb. */
- if (strstr (name, "_from_thumb") != NULL)
- name += 2;
+ /* On soft-float targets, __truncdfsf2 is called to convert promoted
+ arguments to their argument types in non-prototyped
+ functions. */
+ if (strncmp (name, "__truncdfsf2", strlen ("__truncdfsf2")) == 0)
+ return 1;
+ if (strncmp (name, "__aeabi_d2f", strlen ("__aeabi_d2f")) == 0)
+ return 1;
- /* On soft-float targets, __truncdfsf2 is called to convert promoted
- arguments to their argument types in non-prototyped
- functions. */
- if (strncmp (name, "__truncdfsf2", strlen ("__truncdfsf2")) == 0)
- return 1;
- if (strncmp (name, "__aeabi_d2f", strlen ("__aeabi_d2f")) == 0)
- return 1;
+ /* Internal functions related to thread-local storage. */
+ if (strncmp (name, "__tls_get_addr", strlen ("__tls_get_addr")) == 0)
+ return 1;
+ if (strncmp (name, "__aeabi_read_tp", strlen ("__aeabi_read_tp")) == 0)
+ return 1;
+ }
+ else
+ {
+ /* If we run against a stripped glibc, we may be unable to identify
+ special functions by name. Check for one important case,
+ __aeabi_read_tp, by comparing the *code* against the default
+ implementation (this is hand-written ARM assembler in glibc). */
- /* Internal functions related to thread-local storage. */
- if (strncmp (name, "__tls_get_addr", strlen ("__tls_get_addr")) == 0)
- return 1;
- if (strncmp (name, "__aeabi_read_tp", strlen ("__aeabi_read_tp")) == 0)
- return 1;
+ if (!is_thumb
+ && read_memory_unsigned_integer (pc, 4, byte_order_for_code)
+ == 0xe3e00a0f /* mov r0, #0xffff0fff */
+ && read_memory_unsigned_integer (pc + 4, 4, byte_order_for_code)
+ == 0xe240f01f) /* sub pc, r0, #31 */
+ return 1;
+ }
return 0;
}
constant = read_memory_unsigned_integer (loc, 4, byte_order);
regs[bits (insn, 8, 10)] = pv_constant (constant);
}
- else if ((insn & 0xe000) == 0xe000)
+ else if (thumb_insn_size (insn) == 4) /* 32-bit Thumb-2 instructions. */
{
unsigned short inst2;
if (bit (inst2, 12) == 0)
nextpc = nextpc & 0xfffffffc;
- if (!skip_prologue_function (nextpc))
+ if (!skip_prologue_function (gdbarch, nextpc,
+ bit (inst2, 12) != 0))
break;
}
}
else
{
- unsigned int insn
- = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
-
- if ((insn & 0x0e5f0000) == 0x041f0000) /* ldr Rd, #immed */
- {
- address = bits (insn, 0, 11);
- *destreg = bits (insn, 12, 15);
- *offset = 4;
- }
- else if ((insn & 0x0ff00000) == 0x03000000) /* movw Rd, #const */
- {
- low = EXTRACT_MOVW_MOVT_IMM_A (insn);
+ unsigned int insn
+ = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
- insn
- = read_memory_unsigned_integer (pc + 4, 4, byte_order_for_code);
+ if ((insn & 0x0e5f0000) == 0x041f0000) /* ldr Rd, #immed */
+ {
+ address = bits (insn, 0, 11);
+ *destreg = bits (insn, 12, 15);
+ *offset = 4;
+ }
+ else if ((insn & 0x0ff00000) == 0x03000000) /* movw Rd, #const */
+ {
+ low = EXTRACT_MOVW_MOVT_IMM_A (insn);
- if ((insn & 0x0ff00000) == 0x03400000) /* movt Rd, #const */
- high = EXTRACT_MOVW_MOVT_IMM_A (insn);
+ insn
+ = read_memory_unsigned_integer (pc + 4, 4, byte_order_for_code);
- address = (high << 16 | low);
- *destreg = bits (insn, 12, 15);
- *offset = 8;
- }
+ if ((insn & 0x0ff00000) == 0x03400000) /* movt Rd, #const */
+ {
+ high = EXTRACT_MOVW_MOVT_IMM_A (insn);
+ *destreg = bits (insn, 12, 15);
+ *offset = 8;
+ address = (high << 16 | low);
+ }
+ }
}
return address;
instruction sequence is not for stack protector. If symbol is
removed, we conservatively think this sequence is for stack protector. */
if (stack_chk_guard
- && strcmp (SYMBOL_LINKAGE_NAME(stack_chk_guard), "__stack_chk_guard"))
+ && strncmp (SYMBOL_LINKAGE_NAME (stack_chk_guard), "__stack_chk_guard",
+ strlen ("__stack_chk_guard")) != 0)
return pc;
if (is_thumb)
return 0;
default:
- internal_error (__FILE__, __LINE__, "bad value in switch");
+ internal_error (__FILE__, __LINE__, _("bad value in switch"));
}
}
the stack. */
CORE_ADDR dest = BranchDest (current_pc, insn);
- if (skip_prologue_function (dest))
+ if (skip_prologue_function (gdbarch, dest, 0))
continue;
else
break;
else if (arm_instruction_changes_pc (insn))
/* Don't scan past anything that might change control flow. */
break;
- else if ((insn & 0xfe500000) == 0xe8100000) /* ldm */
- {
- /* Ignore block loads from the stack, potentially copying
- parameters from memory. */
- if (pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
- continue;
- else
- break;
- }
- else if ((insn & 0xfc500000) == 0xe4100000)
- {
- /* Similarly ignore single loads from the stack. */
- if (pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
- continue;
- else
- break;
- }
+ else if ((insn & 0xfe500000) == 0xe8100000 /* ldm */
+ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
+ /* Ignore block loads from the stack, potentially copying
+ parameters from memory. */
+ continue;
+ else if ((insn & 0xfc500000) == 0xe4100000
+ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
+ /* Similarly ignore single loads from the stack. */
+ continue;
else if ((insn & 0xffff0ff0) == 0xe1a00000)
/* MOV Rd, Rm. Skip register copies, i.e. saves to another
register instead of the stack. */
if (cache->prev_sp == 0)
return;
+ /* Use function start address as part of the frame ID. If we cannot
+ identify the start address (due to missing symbol information),
+ fall back to just using the current PC. */
func = get_frame_func (this_frame);
+ if (!func)
+ func = pc;
+
id = frame_id_build (cache->prev_sp, func);
*this_id = id;
}
struct frame_unwind arm_prologue_unwind = {
NORMAL_FRAME,
+ default_frame_unwind_stop_reason,
arm_prologue_this_id,
arm_prologue_prev_register,
NULL,
default_frame_sniffer
};
-static struct arm_prologue_cache *
-arm_make_stub_cache (struct frame_info *this_frame)
-{
- struct arm_prologue_cache *cache;
-
- cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
- cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
+/* Maintain a list of ARM exception table entries per objfile, similar to the
+ list of mapping symbols. We only cache entries for standard ARM-defined
+ personality routines; the cache will contain only the frame unwinding
+ instructions associated with the entry (not the descriptors). */
- cache->prev_sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM);
+static const struct objfile_data *arm_exidx_data_key;
- return cache;
-}
+struct arm_exidx_entry
+{
+ bfd_vma addr;
+ gdb_byte *entry;
+};
+typedef struct arm_exidx_entry arm_exidx_entry_s;
+DEF_VEC_O(arm_exidx_entry_s);
-/* Our frame ID for a stub frame is the current SP and LR. */
+struct arm_exidx_data
+{
+ VEC(arm_exidx_entry_s) **section_maps;
+};
static void
-arm_stub_this_id (struct frame_info *this_frame,
- void **this_cache,
- struct frame_id *this_id)
+arm_exidx_data_free (struct objfile *objfile, void *arg)
{
- struct arm_prologue_cache *cache;
-
- if (*this_cache == NULL)
- *this_cache = arm_make_stub_cache (this_frame);
- cache = *this_cache;
+ struct arm_exidx_data *data = arg;
+ unsigned int i;
- *this_id = frame_id_build (cache->prev_sp, get_frame_pc (this_frame));
+ for (i = 0; i < objfile->obfd->section_count; i++)
+ VEC_free (arm_exidx_entry_s, data->section_maps[i]);
}
-static int
-arm_stub_unwind_sniffer (const struct frame_unwind *self,
- struct frame_info *this_frame,
- void **this_prologue_cache)
+static inline int
+arm_compare_exidx_entries (const struct arm_exidx_entry *lhs,
+ const struct arm_exidx_entry *rhs)
{
- CORE_ADDR addr_in_block;
- char dummy[4];
-
- addr_in_block = get_frame_address_in_block (this_frame);
- if (in_plt_section (addr_in_block, NULL)
- /* We also use the stub winder if the target memory is unreadable
- to avoid having the prologue unwinder trying to read it. */
- || target_read_memory (get_frame_pc (this_frame), dummy, 4) != 0)
- return 1;
-
- return 0;
+ return lhs->addr < rhs->addr;
}
-struct frame_unwind arm_stub_unwind = {
- NORMAL_FRAME,
- arm_stub_this_id,
- arm_prologue_prev_register,
- NULL,
- arm_stub_unwind_sniffer
-};
-
-static CORE_ADDR
-arm_normal_frame_base (struct frame_info *this_frame, void **this_cache)
+static struct obj_section *
+arm_obj_section_from_vma (struct objfile *objfile, bfd_vma vma)
{
- struct arm_prologue_cache *cache;
+ struct obj_section *osect;
- if (*this_cache == NULL)
- *this_cache = arm_make_prologue_cache (this_frame);
- cache = *this_cache;
-
- return cache->prev_sp - cache->framesize;
-}
-
-struct frame_base arm_normal_base = {
- &arm_prologue_unwind,
- arm_normal_frame_base,
- arm_normal_frame_base,
- arm_normal_frame_base
-};
+ ALL_OBJFILE_OSECTIONS (objfile, osect)
+ if (bfd_get_section_flags (objfile->obfd,
+ osect->the_bfd_section) & SEC_ALLOC)
+ {
+ bfd_vma start, size;
+ start = bfd_get_section_vma (objfile->obfd, osect->the_bfd_section);
+ size = bfd_get_section_size (osect->the_bfd_section);
-/* Assuming THIS_FRAME is a dummy, return the frame ID of that
- dummy frame. The frame ID's base needs to match the TOS value
- saved by save_dummy_frame_tos() and returned from
- arm_push_dummy_call, and the PC needs to match the dummy frame's
- breakpoint. */
+ if (start <= vma && vma < start + size)
+ return osect;
+ }
-static struct frame_id
-arm_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
-{
- return frame_id_build (get_frame_register_unsigned (this_frame,
- ARM_SP_REGNUM),
- get_frame_pc (this_frame));
+ return NULL;
}
-/* Given THIS_FRAME, find the previous frame's resume PC (which will
- be used to construct the previous frame's ID, after looking up the
- containing function). */
-
-static CORE_ADDR
-arm_unwind_pc (struct gdbarch *gdbarch, struct frame_info *this_frame)
-{
- CORE_ADDR pc;
- pc = frame_unwind_register_unsigned (this_frame, ARM_PC_REGNUM);
- return arm_addr_bits_remove (gdbarch, pc);
-}
+/* Parse contents of exception table and exception index sections
+ of OBJFILE, and fill in the exception table entry cache.
-static CORE_ADDR
-arm_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame)
-{
- return frame_unwind_register_unsigned (this_frame, ARM_SP_REGNUM);
-}
+ For each entry that refers to a standard ARM-defined personality
+ routine, extract the frame unwinding instructions (from either
+ the index or the table section). The unwinding instructions
+ are normalized by:
+ - extracting them from the rest of the table data
+ - converting to host endianness
+ - appending the implicit 0xb0 ("Finish") code
-static struct value *
-arm_dwarf2_prev_register (struct frame_info *this_frame, void **this_cache,
- int regnum)
-{
- struct gdbarch * gdbarch = get_frame_arch (this_frame);
- CORE_ADDR lr, cpsr;
- ULONGEST t_bit = arm_psr_thumb_bit (gdbarch);
+ The extracted and normalized instructions are stored for later
+ retrieval by the arm_find_exidx_entry routine. */
+
+static void
+arm_exidx_new_objfile (struct objfile *objfile)
+{
+ struct cleanup *cleanups;
+ struct arm_exidx_data *data;
+ asection *exidx, *extab;
+ bfd_vma exidx_vma = 0, extab_vma = 0;
+ bfd_size_type exidx_size = 0, extab_size = 0;
+ gdb_byte *exidx_data = NULL, *extab_data = NULL;
+ LONGEST i;
+
+ /* If we've already touched this file, do nothing. */
+ if (!objfile || objfile_data (objfile, arm_exidx_data_key) != NULL)
+ return;
+ cleanups = make_cleanup (null_cleanup, NULL);
- switch (regnum)
+ /* Read contents of exception table and index. */
+ exidx = bfd_get_section_by_name (objfile->obfd, ".ARM.exidx");
+ if (exidx)
{
- case ARM_PC_REGNUM:
- /* The PC is normally copied from the return column, which
- describes saves of LR. However, that version may have an
- extra bit set to indicate Thumb state. The bit is not
- part of the PC. */
- lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
- return frame_unwind_got_constant (this_frame, regnum,
- arm_addr_bits_remove (gdbarch, lr));
-
- case ARM_PS_REGNUM:
- /* Reconstruct the T bit; see arm_prologue_prev_register for details. */
- cpsr = get_frame_register_unsigned (this_frame, regnum);
- lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
- if (IS_THUMB_ADDR (lr))
- cpsr |= t_bit;
- else
- cpsr &= ~t_bit;
- return frame_unwind_got_constant (this_frame, regnum, cpsr);
+ exidx_vma = bfd_section_vma (objfile->obfd, exidx);
+ exidx_size = bfd_get_section_size (exidx);
+ exidx_data = xmalloc (exidx_size);
+ make_cleanup (xfree, exidx_data);
- default:
- internal_error (__FILE__, __LINE__,
- _("Unexpected register %d"), regnum);
+ if (!bfd_get_section_contents (objfile->obfd, exidx,
+ exidx_data, 0, exidx_size))
+ {
+ do_cleanups (cleanups);
+ return;
+ }
}
-}
-static void
-arm_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
- struct dwarf2_frame_state_reg *reg,
- struct frame_info *this_frame)
-{
- switch (regnum)
+ extab = bfd_get_section_by_name (objfile->obfd, ".ARM.extab");
+ if (extab)
{
- case ARM_PC_REGNUM:
- case ARM_PS_REGNUM:
- reg->how = DWARF2_FRAME_REG_FN;
- reg->loc.fn = arm_dwarf2_prev_register;
- break;
- case ARM_SP_REGNUM:
- reg->how = DWARF2_FRAME_REG_CFA;
- break;
- }
-}
+ extab_vma = bfd_section_vma (objfile->obfd, extab);
+ extab_size = bfd_get_section_size (extab);
+ extab_data = xmalloc (extab_size);
+ make_cleanup (xfree, extab_data);
-/* Return true if we are in the function's epilogue, i.e. after the
- instruction that destroyed the function's stack frame. */
+ if (!bfd_get_section_contents (objfile->obfd, extab,
+ extab_data, 0, extab_size))
+ {
+ do_cleanups (cleanups);
+ return;
+ }
+ }
-static int
-thumb_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
-{
- enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- unsigned int insn, insn2;
- int found_return = 0, found_stack_adjust = 0;
- CORE_ADDR func_start, func_end;
- CORE_ADDR scan_pc;
- gdb_byte buf[4];
+ /* Allocate exception table data structure. */
+ data = OBSTACK_ZALLOC (&objfile->objfile_obstack, struct arm_exidx_data);
+ set_objfile_data (objfile, arm_exidx_data_key, data);
+ data->section_maps = OBSTACK_CALLOC (&objfile->objfile_obstack,
+ objfile->obfd->section_count,
+ VEC(arm_exidx_entry_s) *);
- if (!find_pc_partial_function (pc, NULL, &func_start, &func_end))
- return 0;
+ /* Fill in exception table. */
+ for (i = 0; i < exidx_size / 8; i++)
+ {
+ struct arm_exidx_entry new_exidx_entry;
+ bfd_vma idx = bfd_h_get_32 (objfile->obfd, exidx_data + i * 8);
+ bfd_vma val = bfd_h_get_32 (objfile->obfd, exidx_data + i * 8 + 4);
+ bfd_vma addr = 0, word = 0;
+ int n_bytes = 0, n_words = 0;
+ struct obj_section *sec;
+ gdb_byte *entry = NULL;
- /* The epilogue is a sequence of instructions along the following lines:
+ /* Extract address of start of function. */
+ idx = ((idx & 0x7fffffff) ^ 0x40000000) - 0x40000000;
+ idx += exidx_vma + i * 8;
- - add stack frame size to SP or FP
- - [if frame pointer used] restore SP from FP
- - restore registers from SP [may include PC]
- - a return-type instruction [if PC wasn't already restored]
+ /* Find section containing function and compute section offset. */
+ sec = arm_obj_section_from_vma (objfile, idx);
+ if (sec == NULL)
+ continue;
+ idx -= bfd_get_section_vma (objfile->obfd, sec->the_bfd_section);
- In a first pass, we scan forward from the current PC and verify the
- instructions we find as compatible with this sequence, ending in a
- return instruction.
+ /* Determine address of exception table entry. */
+ if (val == 1)
+ {
+ /* EXIDX_CANTUNWIND -- no exception table entry present. */
+ }
+ else if ((val & 0xff000000) == 0x80000000)
+ {
+ /* Exception table entry embedded in .ARM.exidx
+ -- must be short form. */
+ word = val;
+ n_bytes = 3;
+ }
+ else if (!(val & 0x80000000))
+ {
+ /* Exception table entry in .ARM.extab. */
+ addr = ((val & 0x7fffffff) ^ 0x40000000) - 0x40000000;
+ addr += exidx_vma + i * 8 + 4;
- However, this is not sufficient to distinguish indirect function calls
- within a function from indirect tail calls in the epilogue in some cases.
- Therefore, if we didn't already find any SP-changing instruction during
- forward scan, we add a backward scanning heuristic to ensure we actually
- are in the epilogue. */
+ if (addr >= extab_vma && addr + 4 <= extab_vma + extab_size)
+ {
+ word = bfd_h_get_32 (objfile->obfd,
+ extab_data + addr - extab_vma);
+ addr += 4;
- scan_pc = pc;
- while (scan_pc < func_end && !found_return)
- {
- if (target_read_memory (scan_pc, buf, 2))
- break;
-
- scan_pc += 2;
- insn = extract_unsigned_integer (buf, 2, byte_order_for_code);
+ if ((word & 0xff000000) == 0x80000000)
+ {
+ /* Short form. */
+ n_bytes = 3;
+ }
+ else if ((word & 0xff000000) == 0x81000000
+ || (word & 0xff000000) == 0x82000000)
+ {
+ /* Long form. */
+ n_bytes = 2;
+ n_words = ((word >> 16) & 0xff);
+ }
+ else if (!(word & 0x80000000))
+ {
+ bfd_vma pers;
+ struct obj_section *pers_sec;
+ int gnu_personality = 0;
+
+ /* Custom personality routine. */
+ pers = ((word & 0x7fffffff) ^ 0x40000000) - 0x40000000;
+ pers = UNMAKE_THUMB_ADDR (pers + addr - 4);
+
+ /* Check whether we've got one of the variants of the
+ GNU personality routines. */
+ pers_sec = arm_obj_section_from_vma (objfile, pers);
+ if (pers_sec)
+ {
+ static const char *personality[] =
+ {
+ "__gcc_personality_v0",
+ "__gxx_personality_v0",
+ "__gcj_personality_v0",
+ "__gnu_objc_personality_v0",
+ NULL
+ };
+
+ CORE_ADDR pc = pers + obj_section_offset (pers_sec);
+ int k;
+
+ for (k = 0; personality[k]; k++)
+ if (lookup_minimal_symbol_by_pc_name
+ (pc, personality[k], objfile))
+ {
+ gnu_personality = 1;
+ break;
+ }
+ }
- if ((insn & 0xff80) == 0x4700) /* bx <Rm> */
- found_return = 1;
- else if (insn == 0x46f7) /* mov pc, lr */
- found_return = 1;
- else if (insn == 0x46bd) /* mov sp, r7 */
- found_stack_adjust = 1;
- else if ((insn & 0xff00) == 0xb000) /* add sp, imm or sub sp, imm */
- found_stack_adjust = 1;
- else if ((insn & 0xfe00) == 0xbc00) /* pop <registers> */
- {
- found_stack_adjust = 1;
- if (insn & 0x0100) /* <registers> include PC. */
- found_return = 1;
+ /* If so, the next word contains a word count in the high
+ byte, followed by the same unwind instructions as the
+ pre-defined forms. */
+ if (gnu_personality
+ && addr + 4 <= extab_vma + extab_size)
+ {
+ word = bfd_h_get_32 (objfile->obfd,
+ extab_data + addr - extab_vma);
+ addr += 4;
+ n_bytes = 3;
+ n_words = ((word >> 24) & 0xff);
+ }
+ }
+ }
}
- else if ((insn & 0xe000) == 0xe000) /* 32-bit Thumb-2 instruction */
+
+ /* Sanity check address. */
+ if (n_words)
+ if (addr < extab_vma || addr + 4 * n_words > extab_vma + extab_size)
+ n_words = n_bytes = 0;
+
+ /* The unwind instructions reside in WORD (only the N_BYTES least
+ significant bytes are valid), followed by N_WORDS words in the
+ extab section starting at ADDR. */
+ if (n_bytes || n_words)
{
- if (target_read_memory (scan_pc, buf, 2))
- break;
+ gdb_byte *p = entry = obstack_alloc (&objfile->objfile_obstack,
+ n_bytes + n_words * 4 + 1);
- scan_pc += 2;
- insn2 = extract_unsigned_integer (buf, 2, byte_order_for_code);
+ while (n_bytes--)
+ *p++ = (gdb_byte) ((word >> (8 * n_bytes)) & 0xff);
- if (insn == 0xe8bd) /* ldm.w sp!, <registers> */
- {
- found_stack_adjust = 1;
- if (insn2 & 0x8000) /* <registers> include PC. */
- found_return = 1;
- }
- else if (insn == 0xf85d /* ldr.w <Rt>, [sp], #4 */
- && (insn2 & 0x0fff) == 0x0b04)
+ while (n_words--)
{
- found_stack_adjust = 1;
- if ((insn2 & 0xf000) == 0xf000) /* <Rt> is PC. */
- found_return = 1;
+ word = bfd_h_get_32 (objfile->obfd,
+ extab_data + addr - extab_vma);
+ addr += 4;
+
+ *p++ = (gdb_byte) ((word >> 24) & 0xff);
+ *p++ = (gdb_byte) ((word >> 16) & 0xff);
+ *p++ = (gdb_byte) ((word >> 8) & 0xff);
+ *p++ = (gdb_byte) (word & 0xff);
}
- else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, <list> */
- && (insn2 & 0x0e00) == 0x0a00)
- found_stack_adjust = 1;
- else
- break;
+
+ /* Implied "Finish" to terminate the list. */
+ *p++ = 0xb0;
}
- else
- break;
+
+ /* Push entry onto vector. They are guaranteed to always
+ appear in order of increasing addresses. */
+ new_exidx_entry.addr = idx;
+ new_exidx_entry.entry = entry;
+ VEC_safe_push (arm_exidx_entry_s,
+ data->section_maps[sec->the_bfd_section->index],
+ &new_exidx_entry);
}
- if (!found_return)
- return 0;
+ do_cleanups (cleanups);
+}
- /* Since any instruction in the epilogue sequence, with the possible
- exception of return itself, updates the stack pointer, we need to
- scan backwards for at most one instruction. Try either a 16-bit or
- a 32-bit instruction. This is just a heuristic, so we do not worry
- too much about false positives. */
+/* Search for the exception table entry covering MEMADDR. If one is found,
+ return a pointer to its data. Otherwise, return 0. If START is non-NULL,
+ set *START to the start of the region covered by this entry. */
- if (!found_stack_adjust)
+static gdb_byte *
+arm_find_exidx_entry (CORE_ADDR memaddr, CORE_ADDR *start)
+{
+ struct obj_section *sec;
+
+ sec = find_pc_section (memaddr);
+ if (sec != NULL)
{
- if (pc - 4 < func_start)
- return 0;
- if (target_read_memory (pc - 4, buf, 4))
- return 0;
+ struct arm_exidx_data *data;
+ VEC(arm_exidx_entry_s) *map;
+ struct arm_exidx_entry map_key = { memaddr - obj_section_addr (sec), 0 };
+ unsigned int idx;
- insn = extract_unsigned_integer (buf, 2, byte_order_for_code);
- insn2 = extract_unsigned_integer (buf + 2, 2, byte_order_for_code);
+ data = objfile_data (sec->objfile, arm_exidx_data_key);
+ if (data != NULL)
+ {
+ map = data->section_maps[sec->the_bfd_section->index];
+ if (!VEC_empty (arm_exidx_entry_s, map))
+ {
+ struct arm_exidx_entry *map_sym;
- if (insn2 == 0x46bd) /* mov sp, r7 */
- found_stack_adjust = 1;
- else if ((insn2 & 0xff00) == 0xb000) /* add sp, imm or sub sp, imm */
- found_stack_adjust = 1;
- else if ((insn2 & 0xff00) == 0xbc00) /* pop <registers> without PC */
- found_stack_adjust = 1;
- else if (insn == 0xe8bd) /* ldm.w sp!, <registers> */
- found_stack_adjust = 1;
- else if (insn == 0xf85d /* ldr.w <Rt>, [sp], #4 */
- && (insn2 & 0x0fff) == 0x0b04)
- found_stack_adjust = 1;
- else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, <list> */
- && (insn2 & 0x0e00) == 0x0a00)
- found_stack_adjust = 1;
+ idx = VEC_lower_bound (arm_exidx_entry_s, map, &map_key,
+ arm_compare_exidx_entries);
+
+ /* VEC_lower_bound finds the earliest ordered insertion
+ point. If the following symbol starts at this exact
+ address, we use that; otherwise, the preceding
+ exception table entry covers this address. */
+ if (idx < VEC_length (arm_exidx_entry_s, map))
+ {
+ map_sym = VEC_index (arm_exidx_entry_s, map, idx);
+ if (map_sym->addr == map_key.addr)
+ {
+ if (start)
+ *start = map_sym->addr + obj_section_addr (sec);
+ return map_sym->entry;
+ }
+ }
+
+ if (idx > 0)
+ {
+ map_sym = VEC_index (arm_exidx_entry_s, map, idx - 1);
+ if (start)
+ *start = map_sym->addr + obj_section_addr (sec);
+ return map_sym->entry;
+ }
+ }
+ }
}
- return found_stack_adjust;
+ return NULL;
}
-/* Return true if we are in the function's epilogue, i.e. after the
- instruction that destroyed the function's stack frame. */
-
-static int
-arm_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
-{
- enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- unsigned int insn;
- int found_return, found_stack_adjust;
- CORE_ADDR func_start, func_end;
+/* Given the current frame THIS_FRAME, and its associated frame unwinding
+ instruction list from the ARM exception table entry ENTRY, allocate and
+ return a prologue cache structure describing how to unwind this frame.
- if (arm_pc_is_thumb (gdbarch, pc))
- return thumb_in_function_epilogue_p (gdbarch, pc);
+ Return NULL if the unwinding instruction list contains a "spare",
+ "reserved" or "refuse to unwind" instruction as defined in section
+ "9.3 Frame unwinding instructions" of the "Exception Handling ABI
+ for the ARM Architecture" document. */
- if (!find_pc_partial_function (pc, NULL, &func_start, &func_end))
- return 0;
+static struct arm_prologue_cache *
+arm_exidx_fill_cache (struct frame_info *this_frame, gdb_byte *entry)
+{
+ CORE_ADDR vsp = 0;
+ int vsp_valid = 0;
- /* We are in the epilogue if the previous instruction was a stack
- adjustment and the next instruction is a possible return (bx, mov
- pc, or pop). We could have to scan backwards to find the stack
- adjustment, or forwards to find the return, but this is a decent
- approximation. First scan forwards. */
+ struct arm_prologue_cache *cache;
+ cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
+ cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
- found_return = 0;
- insn = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
- if (bits (insn, 28, 31) != INST_NV)
+ for (;;)
{
- if ((insn & 0x0ffffff0) == 0x012fff10)
- /* BX. */
- found_return = 1;
- else if ((insn & 0x0ffffff0) == 0x01a0f000)
- /* MOV PC. */
- found_return = 1;
- else if ((insn & 0x0fff0000) == 0x08bd0000
- && (insn & 0x0000c000) != 0)
- /* POP (LDMIA), including PC or LR. */
- found_return = 1;
- }
+ gdb_byte insn;
- if (!found_return)
- return 0;
+ /* Whenever we reload SP, we actually have to retrieve its
+ actual value in the current frame. */
+ if (!vsp_valid)
+ {
+ if (trad_frame_realreg_p (cache->saved_regs, ARM_SP_REGNUM))
+ {
+ int reg = cache->saved_regs[ARM_SP_REGNUM].realreg;
+ vsp = get_frame_register_unsigned (this_frame, reg);
+ }
+ else
+ {
+ CORE_ADDR addr = cache->saved_regs[ARM_SP_REGNUM].addr;
+ vsp = get_frame_memory_unsigned (this_frame, addr, 4);
+ }
- /* Scan backwards. This is just a heuristic, so do not worry about
- false positives from mode changes. */
+ vsp_valid = 1;
+ }
- if (pc < func_start + 4)
- return 0;
+ /* Decode next unwind instruction. */
+ insn = *entry++;
- found_stack_adjust = 0;
- insn = read_memory_unsigned_integer (pc - 4, 4, byte_order_for_code);
- if (bits (insn, 28, 31) != INST_NV)
- {
- if ((insn & 0x0df0f000) == 0x0080d000)
- /* ADD SP (register or immediate). */
- found_stack_adjust = 1;
- else if ((insn & 0x0df0f000) == 0x0040d000)
- /* SUB SP (register or immediate). */
- found_stack_adjust = 1;
- else if ((insn & 0x0ffffff0) == 0x01a0d000)
- /* MOV SP. */
- found_stack_adjust = 1;
- else if ((insn & 0x0fff0000) == 0x08bd0000)
- /* POP (LDMIA). */
- found_stack_adjust = 1;
- }
+ if ((insn & 0xc0) == 0)
+ {
+ int offset = insn & 0x3f;
+ vsp += (offset << 2) + 4;
+ }
+ else if ((insn & 0xc0) == 0x40)
+ {
+ int offset = insn & 0x3f;
+ vsp -= (offset << 2) + 4;
+ }
+ else if ((insn & 0xf0) == 0x80)
+ {
+ int mask = ((insn & 0xf) << 8) | *entry++;
+ int i;
- if (found_stack_adjust)
- return 1;
+ /* The special case of an all-zero mask identifies
+ "Refuse to unwind". We return NULL to fall back
+ to the prologue analyzer. */
+ if (mask == 0)
+ return NULL;
- return 0;
-}
+ /* Pop registers r4..r15 under mask. */
+ for (i = 0; i < 12; i++)
+ if (mask & (1 << i))
+ {
+ cache->saved_regs[4 + i].addr = vsp;
+ vsp += 4;
+ }
+ /* Special-case popping SP -- we need to reload vsp. */
+ if (mask & (1 << (ARM_SP_REGNUM - 4)))
+ vsp_valid = 0;
+ }
+ else if ((insn & 0xf0) == 0x90)
+ {
+ int reg = insn & 0xf;
-/* When arguments must be pushed onto the stack, they go on in reverse
- order. The code below implements a FILO (stack) to do this. */
+ /* Reserved cases. */
+ if (reg == ARM_SP_REGNUM || reg == ARM_PC_REGNUM)
+ return NULL;
-struct stack_item
-{
- int len;
- struct stack_item *prev;
- void *data;
-};
+ /* Set SP from another register and mark VSP for reload. */
+ cache->saved_regs[ARM_SP_REGNUM] = cache->saved_regs[reg];
+ vsp_valid = 0;
+ }
+ else if ((insn & 0xf0) == 0xa0)
+ {
+ int count = insn & 0x7;
+ int pop_lr = (insn & 0x8) != 0;
+ int i;
-static struct stack_item *
-push_stack_item (struct stack_item *prev, const void *contents, int len)
-{
- struct stack_item *si;
- si = xmalloc (sizeof (struct stack_item));
- si->data = xmalloc (len);
- si->len = len;
- si->prev = prev;
- memcpy (si->data, contents, len);
- return si;
-}
+ /* Pop r4..r[4+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[4 + i].addr = vsp;
+ vsp += 4;
+ }
-static struct stack_item *
-pop_stack_item (struct stack_item *si)
-{
- struct stack_item *dead = si;
- si = si->prev;
- xfree (dead->data);
- xfree (dead);
- return si;
-}
+ /* If indicated by flag, pop LR as well. */
+ if (pop_lr)
+ {
+ cache->saved_regs[ARM_LR_REGNUM].addr = vsp;
+ vsp += 4;
+ }
+ }
+ else if (insn == 0xb0)
+ {
+ /* We could only have updated PC by popping into it; if so, it
+ will show up as address. Otherwise, copy LR into PC. */
+ if (!trad_frame_addr_p (cache->saved_regs, ARM_PC_REGNUM))
+ cache->saved_regs[ARM_PC_REGNUM]
+ = cache->saved_regs[ARM_LR_REGNUM];
+ /* We're done. */
+ break;
+ }
+ else if (insn == 0xb1)
+ {
+ int mask = *entry++;
+ int i;
-/* Return the alignment (in bytes) of the given type. */
+ /* All-zero mask and mask >= 16 is "spare". */
+ if (mask == 0 || mask >= 16)
+ return NULL;
-static int
-arm_type_align (struct type *t)
-{
- int n;
- int align;
- int falign;
+ /* Pop r0..r3 under mask. */
+ for (i = 0; i < 4; i++)
+ if (mask & (1 << i))
+ {
+ cache->saved_regs[i].addr = vsp;
+ vsp += 4;
+ }
+ }
+ else if (insn == 0xb2)
+ {
+ ULONGEST offset = 0;
+ unsigned shift = 0;
- t = check_typedef (t);
- switch (TYPE_CODE (t))
- {
- default:
- /* Should never happen. */
- internal_error (__FILE__, __LINE__, _("unknown type alignment"));
- return 4;
+ do
+ {
+ offset |= (*entry & 0x7f) << shift;
+ shift += 7;
+ }
+ while (*entry++ & 0x80);
- case TYPE_CODE_PTR:
- case TYPE_CODE_ENUM:
- case TYPE_CODE_INT:
- case TYPE_CODE_FLT:
- case TYPE_CODE_SET:
- case TYPE_CODE_RANGE:
- case TYPE_CODE_BITSTRING:
- case TYPE_CODE_REF:
- case TYPE_CODE_CHAR:
- case TYPE_CODE_BOOL:
- return TYPE_LENGTH (t);
+ vsp += 0x204 + (offset << 2);
+ }
+ else if (insn == 0xb3)
+ {
+ int start = *entry >> 4;
+ int count = (*entry++) & 0xf;
+ int i;
- case TYPE_CODE_ARRAY:
- case TYPE_CODE_COMPLEX:
- /* TODO: What about vector types? */
- return arm_type_align (TYPE_TARGET_TYPE (t));
+ /* Only registers D0..D15 are valid here. */
+ if (start + count >= 16)
+ return NULL;
- case TYPE_CODE_STRUCT:
- case TYPE_CODE_UNION:
- align = 1;
- for (n = 0; n < TYPE_NFIELDS (t); n++)
- {
- falign = arm_type_align (TYPE_FIELD_TYPE (t, n));
- if (falign > align)
- align = falign;
- }
- return align;
- }
-}
+ /* Pop VFP double-precision registers D[start]..D[start+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_D0_REGNUM + start + i].addr = vsp;
+ vsp += 8;
+ }
-/* Possible base types for a candidate for passing and returning in
- VFP registers. */
+ /* Add an extra 4 bytes for FSTMFDX-style stack. */
+ vsp += 4;
+ }
+ else if ((insn & 0xf8) == 0xb8)
+ {
+ int count = insn & 0x7;
+ int i;
-enum arm_vfp_cprc_base_type
-{
- VFP_CPRC_UNKNOWN,
- VFP_CPRC_SINGLE,
- VFP_CPRC_DOUBLE,
- VFP_CPRC_VEC64,
- VFP_CPRC_VEC128
-};
+ /* Pop VFP double-precision registers D[8]..D[8+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_D0_REGNUM + 8 + i].addr = vsp;
+ vsp += 8;
+ }
-/* The length of one element of base type B. */
+ /* Add an extra 4 bytes for FSTMFDX-style stack. */
+ vsp += 4;
+ }
+ else if (insn == 0xc6)
+ {
+ int start = *entry >> 4;
+ int count = (*entry++) & 0xf;
+ int i;
-static unsigned
-arm_vfp_cprc_unit_length (enum arm_vfp_cprc_base_type b)
-{
- switch (b)
- {
- case VFP_CPRC_SINGLE:
- return 4;
- case VFP_CPRC_DOUBLE:
- return 8;
- case VFP_CPRC_VEC64:
- return 8;
- case VFP_CPRC_VEC128:
- return 16;
- default:
- internal_error (__FILE__, __LINE__, _("Invalid VFP CPRC type: %d."),
- (int) b);
- }
-}
+ /* Only registers WR0..WR15 are valid. */
+ if (start + count >= 16)
+ return NULL;
-/* The character ('s', 'd' or 'q') for the type of VFP register used
- for passing base type B. */
+ /* Pop iwmmx registers WR[start]..WR[start+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_WR0_REGNUM + start + i].addr = vsp;
+ vsp += 8;
+ }
+ }
+ else if (insn == 0xc7)
+ {
+ int mask = *entry++;
+ int i;
-static int
-arm_vfp_cprc_reg_char (enum arm_vfp_cprc_base_type b)
-{
- switch (b)
- {
- case VFP_CPRC_SINGLE:
- return 's';
- case VFP_CPRC_DOUBLE:
- return 'd';
- case VFP_CPRC_VEC64:
- return 'd';
- case VFP_CPRC_VEC128:
- return 'q';
- default:
- internal_error (__FILE__, __LINE__, _("Invalid VFP CPRC type: %d."),
- (int) b);
- }
-}
+ /* All-zero mask and mask >= 16 is "spare". */
+ if (mask == 0 || mask >= 16)
+ return NULL;
-/* Determine whether T may be part of a candidate for passing and
- returning in VFP registers, ignoring the limit on the total number
- of components. If *BASE_TYPE is VFP_CPRC_UNKNOWN, set it to the
- classification of the first valid component found; if it is not
- VFP_CPRC_UNKNOWN, all components must have the same classification
- as *BASE_TYPE. If it is found that T contains a type not permitted
- for passing and returning in VFP registers, a type differently
- classified from *BASE_TYPE, or two types differently classified
- from each other, return -1, otherwise return the total number of
- base-type elements found (possibly 0 in an empty structure or
- array). Vectors and complex types are not currently supported,
- matching the generic AAPCS support. */
+ /* Pop iwmmx general-purpose registers WCGR0..WCGR3 under mask. */
+ for (i = 0; i < 4; i++)
+ if (mask & (1 << i))
+ {
+ cache->saved_regs[ARM_WCGR0_REGNUM + i].addr = vsp;
+ vsp += 4;
+ }
+ }
+ else if ((insn & 0xf8) == 0xc0)
+ {
+ int count = insn & 0x7;
+ int i;
-static int
-arm_vfp_cprc_sub_candidate (struct type *t,
- enum arm_vfp_cprc_base_type *base_type)
-{
- t = check_typedef (t);
- switch (TYPE_CODE (t))
- {
- case TYPE_CODE_FLT:
- switch (TYPE_LENGTH (t))
+ /* Pop iwmmx registers WR[10]..WR[10+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_WR0_REGNUM + 10 + i].addr = vsp;
+ vsp += 8;
+ }
+ }
+ else if (insn == 0xc8)
{
- case 4:
- if (*base_type == VFP_CPRC_UNKNOWN)
- *base_type = VFP_CPRC_SINGLE;
- else if (*base_type != VFP_CPRC_SINGLE)
- return -1;
- return 1;
+ int start = *entry >> 4;
+ int count = (*entry++) & 0xf;
+ int i;
- case 8:
- if (*base_type == VFP_CPRC_UNKNOWN)
- *base_type = VFP_CPRC_DOUBLE;
- else if (*base_type != VFP_CPRC_DOUBLE)
- return -1;
- return 1;
+ /* Only registers D0..D31 are valid. */
+ if (start + count >= 16)
+ return NULL;
- default:
- return -1;
+ /* Pop VFP double-precision registers
+ D[16+start]..D[16+start+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_D0_REGNUM + 16 + start + i].addr = vsp;
+ vsp += 8;
+ }
}
- break;
+ else if (insn == 0xc9)
+ {
+ int start = *entry >> 4;
+ int count = (*entry++) & 0xf;
+ int i;
- case TYPE_CODE_ARRAY:
- {
- int count;
- unsigned unitlen;
- count = arm_vfp_cprc_sub_candidate (TYPE_TARGET_TYPE (t), base_type);
- if (count == -1)
- return -1;
- if (TYPE_LENGTH (t) == 0)
- {
- gdb_assert (count == 0);
- return 0;
- }
- else if (count == 0)
- return -1;
- unitlen = arm_vfp_cprc_unit_length (*base_type);
- gdb_assert ((TYPE_LENGTH (t) % unitlen) == 0);
- return TYPE_LENGTH (t) / unitlen;
- }
- break;
+ /* Pop VFP double-precision registers D[start]..D[start+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_D0_REGNUM + start + i].addr = vsp;
+ vsp += 8;
+ }
+ }
+ else if ((insn & 0xf8) == 0xd0)
+ {
+ int count = insn & 0x7;
+ int i;
- case TYPE_CODE_STRUCT:
- {
- int count = 0;
- unsigned unitlen;
- int i;
- for (i = 0; i < TYPE_NFIELDS (t); i++)
- {
- int sub_count = arm_vfp_cprc_sub_candidate (TYPE_FIELD_TYPE (t, i),
- base_type);
- if (sub_count == -1)
- return -1;
- count += sub_count;
- }
- if (TYPE_LENGTH (t) == 0)
- {
- gdb_assert (count == 0);
- return 0;
- }
- else if (count == 0)
- return -1;
- unitlen = arm_vfp_cprc_unit_length (*base_type);
- if (TYPE_LENGTH (t) != unitlen * count)
- return -1;
- return count;
- }
+ /* Pop VFP double-precision registers D[8]..D[8+count]. */
+ for (i = 0; i <= count; i++)
+ {
+ cache->saved_regs[ARM_D0_REGNUM + 8 + i].addr = vsp;
+ vsp += 8;
+ }
+ }
+ else
+ {
+ /* Everything else is "spare". */
+ return NULL;
+ }
+ }
- case TYPE_CODE_UNION:
- {
- int count = 0;
- unsigned unitlen;
- int i;
- for (i = 0; i < TYPE_NFIELDS (t); i++)
- {
- int sub_count = arm_vfp_cprc_sub_candidate (TYPE_FIELD_TYPE (t, i),
- base_type);
- if (sub_count == -1)
- return -1;
- count = (count > sub_count ? count : sub_count);
- }
- if (TYPE_LENGTH (t) == 0)
- {
- gdb_assert (count == 0);
- return 0;
- }
- else if (count == 0)
- return -1;
- unitlen = arm_vfp_cprc_unit_length (*base_type);
- if (TYPE_LENGTH (t) != unitlen * count)
- return -1;
- return count;
- }
+ /* If we restore SP from a register, assume this was the frame register.
+ Otherwise just fall back to SP as frame register. */
+ if (trad_frame_realreg_p (cache->saved_regs, ARM_SP_REGNUM))
+ cache->framereg = cache->saved_regs[ARM_SP_REGNUM].realreg;
+ else
+ cache->framereg = ARM_SP_REGNUM;
- default:
- break;
- }
+ /* Determine offset to previous frame. */
+ cache->framesize
+ = vsp - get_frame_register_unsigned (this_frame, cache->framereg);
- return -1;
+ /* We already got the previous SP. */
+ cache->prev_sp = vsp;
+
+ return cache;
}
-/* Determine whether T is a VFP co-processor register candidate (CPRC)
- if passed to or returned from a non-variadic function with the VFP
- ABI in effect. Return 1 if it is, 0 otherwise. If it is, set
- *BASE_TYPE to the base type for T and *COUNT to the number of
- elements of that base type before returning. */
+/* Unwinding via ARM exception table entries. Note that the sniffer
+ already computes a filled-in prologue cache, which is then used
+ with the same arm_prologue_this_id and arm_prologue_prev_register
+ routines also used for prologue-parsing based unwinding. */
static int
-arm_vfp_call_candidate (struct type *t, enum arm_vfp_cprc_base_type *base_type,
- int *count)
+arm_exidx_unwind_sniffer (const struct frame_unwind *self,
+ struct frame_info *this_frame,
+ void **this_prologue_cache)
{
- enum arm_vfp_cprc_base_type b = VFP_CPRC_UNKNOWN;
- int c = arm_vfp_cprc_sub_candidate (t, &b);
- if (c <= 0 || c > 4)
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ CORE_ADDR addr_in_block, exidx_region, func_start;
+ struct arm_prologue_cache *cache;
+ gdb_byte *entry;
+
+ /* See if we have an ARM exception table entry covering this address. */
+ addr_in_block = get_frame_address_in_block (this_frame);
+ entry = arm_find_exidx_entry (addr_in_block, &exidx_region);
+ if (!entry)
return 0;
- *base_type = b;
- *count = c;
- return 1;
-}
-/* Return 1 if the VFP ABI should be used for passing arguments to and
- returning values from a function of type FUNC_TYPE, 0
- otherwise. */
+ /* The ARM exception table does not describe unwind information
+ for arbitrary PC values, but is guaranteed to be correct only
+ at call sites. We have to decide here whether we want to use
+ ARM exception table information for this frame, or fall back
+ to using prologue parsing. (Note that if we have DWARF CFI,
+ this sniffer isn't even called -- CFI is always preferred.)
+
+ Before we make this decision, however, we check whether we
+ actually have *symbol* information for the current frame.
+ If not, prologue parsing would not work anyway, so we might
+ as well use the exception table and hope for the best. */
+ if (find_pc_partial_function (addr_in_block, NULL, &func_start, NULL))
+ {
+ int exc_valid = 0;
+
+ /* If the next frame is "normal", we are at a call site in this
+ frame, so exception information is guaranteed to be valid. */
+ if (get_next_frame (this_frame)
+ && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME)
+ exc_valid = 1;
+
+ /* We also assume exception information is valid if we're currently
+ blocked in a system call. The system library is supposed to
+ ensure this, so that e.g. pthread cancellation works. */
+ if (arm_frame_is_thumb (this_frame))
+ {
+ LONGEST insn;
-static int
-arm_vfp_abi_for_function (struct gdbarch *gdbarch, struct type *func_type)
-{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
- /* Variadic functions always use the base ABI. Assume that functions
- without debug info are not variadic. */
- if (func_type && TYPE_VARARGS (check_typedef (func_type)))
- return 0;
- /* The VFP ABI is only supported as a variant of AAPCS. */
- if (tdep->arm_abi != ARM_ABI_AAPCS)
+ if (safe_read_memory_integer (get_frame_pc (this_frame) - 2, 2,
+ byte_order_for_code, &insn)
+ && (insn & 0xff00) == 0xdf00 /* svc */)
+ exc_valid = 1;
+ }
+ else
+ {
+ LONGEST insn;
+
+ if (safe_read_memory_integer (get_frame_pc (this_frame) - 4, 4,
+ byte_order_for_code, &insn)
+ && (insn & 0x0f000000) == 0x0f000000 /* svc */)
+ exc_valid = 1;
+ }
+
+ /* Bail out if we don't know that exception information is valid. */
+ if (!exc_valid)
+ return 0;
+
+ /* The ARM exception index does not mark the *end* of the region
+ covered by the entry, and some functions will not have any entry.
+ To correctly recognize the end of the covered region, the linker
+ should have inserted dummy records with a CANTUNWIND marker.
+
+ Unfortunately, current versions of GNU ld do not reliably do
+ this, and thus we may have found an incorrect entry above.
+ As a (temporary) sanity check, we only use the entry if it
+ lies *within* the bounds of the function. Note that this check
+ might reject perfectly valid entries that just happen to cover
+ multiple functions; therefore this check ought to be removed
+ once the linker is fixed. */
+ if (func_start > exidx_region)
+ return 0;
+ }
+
+ /* Decode the list of unwinding instructions into a prologue cache.
+ Note that this may fail due to e.g. a "refuse to unwind" code. */
+ cache = arm_exidx_fill_cache (this_frame, entry);
+ if (!cache)
return 0;
- return gdbarch_tdep (gdbarch)->fp_model == ARM_FLOAT_VFP;
+
+ *this_prologue_cache = cache;
+ return 1;
}
-/* We currently only support passing parameters in integer registers, which
- conforms with GCC's default model, and VFP argument passing following
- the VFP variant of AAPCS. Several other variants exist and
- we should probably support some of them based on the selected ABI. */
+struct frame_unwind arm_exidx_unwind = {
+ NORMAL_FRAME,
+ default_frame_unwind_stop_reason,
+ arm_prologue_this_id,
+ arm_prologue_prev_register,
+ NULL,
+ arm_exidx_unwind_sniffer
+};
-static CORE_ADDR
-arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
- struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
- struct value **args, CORE_ADDR sp, int struct_return,
- CORE_ADDR struct_addr)
+static struct arm_prologue_cache *
+arm_make_stub_cache (struct frame_info *this_frame)
{
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- int argnum;
- int argreg;
- int nstack;
- struct stack_item *si = NULL;
- int use_vfp_abi;
- struct type *ftype;
- unsigned vfp_regs_free = (1 << 16) - 1;
+ struct arm_prologue_cache *cache;
- /* Determine the type of this function and whether the VFP ABI
- applies. */
- ftype = check_typedef (value_type (function));
- if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
- ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
- use_vfp_abi = arm_vfp_abi_for_function (gdbarch, ftype);
+ cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
+ cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
- /* Set the return address. For the ARM, the return breakpoint is
- always at BP_ADDR. */
- if (arm_pc_is_thumb (gdbarch, bp_addr))
- bp_addr |= 1;
- regcache_cooked_write_unsigned (regcache, ARM_LR_REGNUM, bp_addr);
+ cache->prev_sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM);
- /* Walk through the list of args and determine how large a temporary
- stack is required. Need to take care here as structs may be
- passed on the stack, and we have to to push them. */
- nstack = 0;
+ return cache;
+}
- argreg = ARM_A1_REGNUM;
- nstack = 0;
+/* Our frame ID for a stub frame is the current SP and LR. */
- /* The struct_return pointer occupies the first parameter
- passing register. */
- if (struct_return)
- {
- if (arm_debug)
- fprintf_unfiltered (gdb_stdlog, "struct return in %s = %s\n",
- gdbarch_register_name (gdbarch, argreg),
- paddress (gdbarch, struct_addr));
- regcache_cooked_write_unsigned (regcache, argreg, struct_addr);
- argreg++;
- }
+static void
+arm_stub_this_id (struct frame_info *this_frame,
+ void **this_cache,
+ struct frame_id *this_id)
+{
+ struct arm_prologue_cache *cache;
- for (argnum = 0; argnum < nargs; argnum++)
- {
- int len;
- struct type *arg_type;
- struct type *target_type;
- enum type_code typecode;
- const bfd_byte *val;
- int align;
- enum arm_vfp_cprc_base_type vfp_base_type;
- int vfp_base_count;
- int may_use_core_reg = 1;
+ if (*this_cache == NULL)
+ *this_cache = arm_make_stub_cache (this_frame);
+ cache = *this_cache;
- arg_type = check_typedef (value_type (args[argnum]));
- len = TYPE_LENGTH (arg_type);
- target_type = TYPE_TARGET_TYPE (arg_type);
- typecode = TYPE_CODE (arg_type);
- val = value_contents (args[argnum]);
+ *this_id = frame_id_build (cache->prev_sp, get_frame_pc (this_frame));
+}
- align = arm_type_align (arg_type);
- /* Round alignment up to a whole number of words. */
- align = (align + INT_REGISTER_SIZE - 1) & ~(INT_REGISTER_SIZE - 1);
- /* Different ABIs have different maximum alignments. */
- if (gdbarch_tdep (gdbarch)->arm_abi == ARM_ABI_APCS)
- {
- /* The APCS ABI only requires word alignment. */
- align = INT_REGISTER_SIZE;
- }
- else
- {
- /* The AAPCS requires at most doubleword alignment. */
- if (align > INT_REGISTER_SIZE * 2)
- align = INT_REGISTER_SIZE * 2;
- }
+static int
+arm_stub_unwind_sniffer (const struct frame_unwind *self,
+ struct frame_info *this_frame,
+ void **this_prologue_cache)
+{
+ CORE_ADDR addr_in_block;
+ char dummy[4];
- if (use_vfp_abi
- && arm_vfp_call_candidate (arg_type, &vfp_base_type,
- &vfp_base_count))
- {
- int regno;
- int unit_length;
- int shift;
- unsigned mask;
+ addr_in_block = get_frame_address_in_block (this_frame);
+ if (in_plt_section (addr_in_block, NULL)
+ /* We also use the stub winder if the target memory is unreadable
+ to avoid having the prologue unwinder trying to read it. */
+ || target_read_memory (get_frame_pc (this_frame), dummy, 4) != 0)
+ return 1;
- /* Because this is a CPRC it cannot go in a core register or
- cause a core register to be skipped for alignment.
- Either it goes in VFP registers and the rest of this loop
- iteration is skipped for this argument, or it goes on the
- stack (and the stack alignment code is correct for this
- case). */
- may_use_core_reg = 0;
+ return 0;
+}
- unit_length = arm_vfp_cprc_unit_length (vfp_base_type);
- shift = unit_length / 4;
- mask = (1 << (shift * vfp_base_count)) - 1;
- for (regno = 0; regno < 16; regno += shift)
- if (((vfp_regs_free >> regno) & mask) == mask)
- break;
+struct frame_unwind arm_stub_unwind = {
+ NORMAL_FRAME,
+ default_frame_unwind_stop_reason,
+ arm_stub_this_id,
+ arm_prologue_prev_register,
+ NULL,
+ arm_stub_unwind_sniffer
+};
- if (regno < 16)
- {
- int reg_char;
- int reg_scaled;
- int i;
+static CORE_ADDR
+arm_normal_frame_base (struct frame_info *this_frame, void **this_cache)
+{
+ struct arm_prologue_cache *cache;
- vfp_regs_free &= ~(mask << regno);
- reg_scaled = regno / shift;
- reg_char = arm_vfp_cprc_reg_char (vfp_base_type);
- for (i = 0; i < vfp_base_count; i++)
- {
- char name_buf[4];
- int regnum;
- if (reg_char == 'q')
- arm_neon_quad_write (gdbarch, regcache, reg_scaled + i,
- val + i * unit_length);
- else
- {
- sprintf (name_buf, "%c%d", reg_char, reg_scaled + i);
- regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
- strlen (name_buf));
- regcache_cooked_write (regcache, regnum,
- val + i * unit_length);
- }
- }
- continue;
- }
- else
- {
- /* This CPRC could not go in VFP registers, so all VFP
- registers are now marked as used. */
- vfp_regs_free = 0;
- }
- }
+ if (*this_cache == NULL)
+ *this_cache = arm_make_prologue_cache (this_frame);
+ cache = *this_cache;
- /* Push stack padding for dowubleword alignment. */
- if (nstack & (align - 1))
- {
- si = push_stack_item (si, val, INT_REGISTER_SIZE);
- nstack += INT_REGISTER_SIZE;
- }
-
- /* Doubleword aligned quantities must go in even register pairs. */
- if (may_use_core_reg
- && argreg <= ARM_LAST_ARG_REGNUM
- && align > INT_REGISTER_SIZE
- && argreg & 1)
- argreg++;
+ return cache->prev_sp - cache->framesize;
+}
- /* If the argument is a pointer to a function, and it is a
- Thumb function, create a LOCAL copy of the value and set
- the THUMB bit in it. */
- if (TYPE_CODE_PTR == typecode
- && target_type != NULL
- && TYPE_CODE_FUNC == TYPE_CODE (check_typedef (target_type)))
- {
- CORE_ADDR regval = extract_unsigned_integer (val, len, byte_order);
- if (arm_pc_is_thumb (gdbarch, regval))
- {
- bfd_byte *copy = alloca (len);
- store_unsigned_integer (copy, len, byte_order,
- MAKE_THUMB_ADDR (regval));
- val = copy;
- }
- }
+struct frame_base arm_normal_base = {
+ &arm_prologue_unwind,
+ arm_normal_frame_base,
+ arm_normal_frame_base,
+ arm_normal_frame_base
+};
- /* Copy the argument to general registers or the stack in
- register-sized pieces. Large arguments are split between
- registers and stack. */
- while (len > 0)
- {
- int partial_len = len < INT_REGISTER_SIZE ? len : INT_REGISTER_SIZE;
+/* Assuming THIS_FRAME is a dummy, return the frame ID of that
+ dummy frame. The frame ID's base needs to match the TOS value
+ saved by save_dummy_frame_tos() and returned from
+ arm_push_dummy_call, and the PC needs to match the dummy frame's
+ breakpoint. */
- if (may_use_core_reg && argreg <= ARM_LAST_ARG_REGNUM)
- {
- /* The argument is being passed in a general purpose
- register. */
- CORE_ADDR regval
- = extract_unsigned_integer (val, partial_len, byte_order);
- if (byte_order == BFD_ENDIAN_BIG)
- regval <<= (INT_REGISTER_SIZE - partial_len) * 8;
- if (arm_debug)
- fprintf_unfiltered (gdb_stdlog, "arg %d in %s = 0x%s\n",
- argnum,
- gdbarch_register_name
- (gdbarch, argreg),
- phex (regval, INT_REGISTER_SIZE));
- regcache_cooked_write_unsigned (regcache, argreg, regval);
- argreg++;
+static struct frame_id
+arm_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
+{
+ return frame_id_build (get_frame_register_unsigned (this_frame,
+ ARM_SP_REGNUM),
+ get_frame_pc (this_frame));
+}
+
+/* Given THIS_FRAME, find the previous frame's resume PC (which will
+ be used to construct the previous frame's ID, after looking up the
+ containing function). */
+
+static CORE_ADDR
+arm_unwind_pc (struct gdbarch *gdbarch, struct frame_info *this_frame)
+{
+ CORE_ADDR pc;
+ pc = frame_unwind_register_unsigned (this_frame, ARM_PC_REGNUM);
+ return arm_addr_bits_remove (gdbarch, pc);
+}
+
+static CORE_ADDR
+arm_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame)
+{
+ return frame_unwind_register_unsigned (this_frame, ARM_SP_REGNUM);
+}
+
+static struct value *
+arm_dwarf2_prev_register (struct frame_info *this_frame, void **this_cache,
+ int regnum)
+{
+ struct gdbarch * gdbarch = get_frame_arch (this_frame);
+ CORE_ADDR lr, cpsr;
+ ULONGEST t_bit = arm_psr_thumb_bit (gdbarch);
+
+ switch (regnum)
+ {
+ case ARM_PC_REGNUM:
+ /* The PC is normally copied from the return column, which
+ describes saves of LR. However, that version may have an
+ extra bit set to indicate Thumb state. The bit is not
+ part of the PC. */
+ lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
+ return frame_unwind_got_constant (this_frame, regnum,
+ arm_addr_bits_remove (gdbarch, lr));
+
+ case ARM_PS_REGNUM:
+ /* Reconstruct the T bit; see arm_prologue_prev_register for details. */
+ cpsr = get_frame_register_unsigned (this_frame, regnum);
+ lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
+ if (IS_THUMB_ADDR (lr))
+ cpsr |= t_bit;
+ else
+ cpsr &= ~t_bit;
+ return frame_unwind_got_constant (this_frame, regnum, cpsr);
+
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Unexpected register %d"), regnum);
+ }
+}
+
+static void
+arm_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
+ struct dwarf2_frame_state_reg *reg,
+ struct frame_info *this_frame)
+{
+ switch (regnum)
+ {
+ case ARM_PC_REGNUM:
+ case ARM_PS_REGNUM:
+ reg->how = DWARF2_FRAME_REG_FN;
+ reg->loc.fn = arm_dwarf2_prev_register;
+ break;
+ case ARM_SP_REGNUM:
+ reg->how = DWARF2_FRAME_REG_CFA;
+ break;
+ }
+}
+
+/* Return true if we are in the function's epilogue, i.e. after the
+ instruction that destroyed the function's stack frame. */
+
+static int
+thumb_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned int insn, insn2;
+ int found_return = 0, found_stack_adjust = 0;
+ CORE_ADDR func_start, func_end;
+ CORE_ADDR scan_pc;
+ gdb_byte buf[4];
+
+ if (!find_pc_partial_function (pc, NULL, &func_start, &func_end))
+ return 0;
+
+ /* The epilogue is a sequence of instructions along the following lines:
+
+ - add stack frame size to SP or FP
+ - [if frame pointer used] restore SP from FP
+ - restore registers from SP [may include PC]
+ - a return-type instruction [if PC wasn't already restored]
+
+ In a first pass, we scan forward from the current PC and verify the
+ instructions we find as compatible with this sequence, ending in a
+ return instruction.
+
+ However, this is not sufficient to distinguish indirect function calls
+ within a function from indirect tail calls in the epilogue in some cases.
+ Therefore, if we didn't already find any SP-changing instruction during
+ forward scan, we add a backward scanning heuristic to ensure we actually
+ are in the epilogue. */
+
+ scan_pc = pc;
+ while (scan_pc < func_end && !found_return)
+ {
+ if (target_read_memory (scan_pc, buf, 2))
+ break;
+
+ scan_pc += 2;
+ insn = extract_unsigned_integer (buf, 2, byte_order_for_code);
+
+ if ((insn & 0xff80) == 0x4700) /* bx <Rm> */
+ found_return = 1;
+ else if (insn == 0x46f7) /* mov pc, lr */
+ found_return = 1;
+ else if (insn == 0x46bd) /* mov sp, r7 */
+ found_stack_adjust = 1;
+ else if ((insn & 0xff00) == 0xb000) /* add sp, imm or sub sp, imm */
+ found_stack_adjust = 1;
+ else if ((insn & 0xfe00) == 0xbc00) /* pop <registers> */
+ {
+ found_stack_adjust = 1;
+ if (insn & 0x0100) /* <registers> include PC. */
+ found_return = 1;
+ }
+ else if (thumb_insn_size (insn) == 4) /* 32-bit Thumb-2 instruction */
+ {
+ if (target_read_memory (scan_pc, buf, 2))
+ break;
+
+ scan_pc += 2;
+ insn2 = extract_unsigned_integer (buf, 2, byte_order_for_code);
+
+ if (insn == 0xe8bd) /* ldm.w sp!, <registers> */
+ {
+ found_stack_adjust = 1;
+ if (insn2 & 0x8000) /* <registers> include PC. */
+ found_return = 1;
}
- else
+ else if (insn == 0xf85d /* ldr.w <Rt>, [sp], #4 */
+ && (insn2 & 0x0fff) == 0x0b04)
{
- /* Push the arguments onto the stack. */
- if (arm_debug)
- fprintf_unfiltered (gdb_stdlog, "arg %d @ sp + %d\n",
- argnum, nstack);
- si = push_stack_item (si, val, INT_REGISTER_SIZE);
- nstack += INT_REGISTER_SIZE;
+ found_stack_adjust = 1;
+ if ((insn2 & 0xf000) == 0xf000) /* <Rt> is PC. */
+ found_return = 1;
}
-
- len -= partial_len;
- val += partial_len;
+ else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, <list> */
+ && (insn2 & 0x0e00) == 0x0a00)
+ found_stack_adjust = 1;
+ else
+ break;
}
+ else
+ break;
}
- /* If we have an odd number of words to push, then decrement the stack
- by one word now, so first stack argument will be dword aligned. */
- if (nstack & 4)
- sp -= 4;
- while (si)
+ if (!found_return)
+ return 0;
+
+ /* Since any instruction in the epilogue sequence, with the possible
+ exception of return itself, updates the stack pointer, we need to
+ scan backwards for at most one instruction. Try either a 16-bit or
+ a 32-bit instruction. This is just a heuristic, so we do not worry
+ too much about false positives. */
+
+ if (!found_stack_adjust)
{
- sp -= si->len;
- write_memory (sp, si->data, si->len);
- si = pop_stack_item (si);
+ if (pc - 4 < func_start)
+ return 0;
+ if (target_read_memory (pc - 4, buf, 4))
+ return 0;
+
+ insn = extract_unsigned_integer (buf, 2, byte_order_for_code);
+ insn2 = extract_unsigned_integer (buf + 2, 2, byte_order_for_code);
+
+ if (insn2 == 0x46bd) /* mov sp, r7 */
+ found_stack_adjust = 1;
+ else if ((insn2 & 0xff00) == 0xb000) /* add sp, imm or sub sp, imm */
+ found_stack_adjust = 1;
+ else if ((insn2 & 0xff00) == 0xbc00) /* pop <registers> without PC */
+ found_stack_adjust = 1;
+ else if (insn == 0xe8bd) /* ldm.w sp!, <registers> */
+ found_stack_adjust = 1;
+ else if (insn == 0xf85d /* ldr.w <Rt>, [sp], #4 */
+ && (insn2 & 0x0fff) == 0x0b04)
+ found_stack_adjust = 1;
+ else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, <list> */
+ && (insn2 & 0x0e00) == 0x0a00)
+ found_stack_adjust = 1;
}
- /* Finally, update teh SP register. */
- regcache_cooked_write_unsigned (regcache, ARM_SP_REGNUM, sp);
+ return found_stack_adjust;
+}
+
+/* Return true if we are in the function's epilogue, i.e. after the
+ instruction that destroyed the function's stack frame. */
+
+static int
+arm_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned int insn;
+ int found_return, found_stack_adjust;
+ CORE_ADDR func_start, func_end;
+
+ if (arm_pc_is_thumb (gdbarch, pc))
+ return thumb_in_function_epilogue_p (gdbarch, pc);
+
+ if (!find_pc_partial_function (pc, NULL, &func_start, &func_end))
+ return 0;
+
+ /* We are in the epilogue if the previous instruction was a stack
+ adjustment and the next instruction is a possible return (bx, mov
+ pc, or pop). We could have to scan backwards to find the stack
+ adjustment, or forwards to find the return, but this is a decent
+ approximation. First scan forwards. */
+
+ found_return = 0;
+ insn = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
+ if (bits (insn, 28, 31) != INST_NV)
+ {
+ if ((insn & 0x0ffffff0) == 0x012fff10)
+ /* BX. */
+ found_return = 1;
+ else if ((insn & 0x0ffffff0) == 0x01a0f000)
+ /* MOV PC. */
+ found_return = 1;
+ else if ((insn & 0x0fff0000) == 0x08bd0000
+ && (insn & 0x0000c000) != 0)
+ /* POP (LDMIA), including PC or LR. */
+ found_return = 1;
+ }
+
+ if (!found_return)
+ return 0;
+
+ /* Scan backwards. This is just a heuristic, so do not worry about
+ false positives from mode changes. */
+
+ if (pc < func_start + 4)
+ return 0;
+
+ found_stack_adjust = 0;
+ insn = read_memory_unsigned_integer (pc - 4, 4, byte_order_for_code);
+ if (bits (insn, 28, 31) != INST_NV)
+ {
+ if ((insn & 0x0df0f000) == 0x0080d000)
+ /* ADD SP (register or immediate). */
+ found_stack_adjust = 1;
+ else if ((insn & 0x0df0f000) == 0x0040d000)
+ /* SUB SP (register or immediate). */
+ found_stack_adjust = 1;
+ else if ((insn & 0x0ffffff0) == 0x01a0d000)
+ /* MOV SP. */
+ found_stack_adjust = 1;
+ else if ((insn & 0x0fff0000) == 0x08bd0000)
+ /* POP (LDMIA). */
+ found_stack_adjust = 1;
+ }
+
+ if (found_stack_adjust)
+ return 1;
+
+ return 0;
+}
+
+
+/* When arguments must be pushed onto the stack, they go on in reverse
+ order. The code below implements a FILO (stack) to do this. */
+
+struct stack_item
+{
+ int len;
+ struct stack_item *prev;
+ void *data;
+};
+
+static struct stack_item *
+push_stack_item (struct stack_item *prev, const void *contents, int len)
+{
+ struct stack_item *si;
+ si = xmalloc (sizeof (struct stack_item));
+ si->data = xmalloc (len);
+ si->len = len;
+ si->prev = prev;
+ memcpy (si->data, contents, len);
+ return si;
+}
+
+static struct stack_item *
+pop_stack_item (struct stack_item *si)
+{
+ struct stack_item *dead = si;
+ si = si->prev;
+ xfree (dead->data);
+ xfree (dead);
+ return si;
+}
+
+
+/* Return the alignment (in bytes) of the given type. */
+
+static int
+arm_type_align (struct type *t)
+{
+ int n;
+ int align;
+ int falign;
+
+ t = check_typedef (t);
+ switch (TYPE_CODE (t))
+ {
+ default:
+ /* Should never happen. */
+ internal_error (__FILE__, __LINE__, _("unknown type alignment"));
+ return 4;
+
+ case TYPE_CODE_PTR:
+ case TYPE_CODE_ENUM:
+ case TYPE_CODE_INT:
+ case TYPE_CODE_FLT:
+ case TYPE_CODE_SET:
+ case TYPE_CODE_RANGE:
+ case TYPE_CODE_BITSTRING:
+ case TYPE_CODE_REF:
+ case TYPE_CODE_CHAR:
+ case TYPE_CODE_BOOL:
+ return TYPE_LENGTH (t);
+
+ case TYPE_CODE_ARRAY:
+ case TYPE_CODE_COMPLEX:
+ /* TODO: What about vector types? */
+ return arm_type_align (TYPE_TARGET_TYPE (t));
+
+ case TYPE_CODE_STRUCT:
+ case TYPE_CODE_UNION:
+ align = 1;
+ for (n = 0; n < TYPE_NFIELDS (t); n++)
+ {
+ falign = arm_type_align (TYPE_FIELD_TYPE (t, n));
+ if (falign > align)
+ align = falign;
+ }
+ return align;
+ }
+}
+
+/* Possible base types for a candidate for passing and returning in
+ VFP registers. */
+
+enum arm_vfp_cprc_base_type
+{
+ VFP_CPRC_UNKNOWN,
+ VFP_CPRC_SINGLE,
+ VFP_CPRC_DOUBLE,
+ VFP_CPRC_VEC64,
+ VFP_CPRC_VEC128
+};
+
+/* The length of one element of base type B. */
+
+static unsigned
+arm_vfp_cprc_unit_length (enum arm_vfp_cprc_base_type b)
+{
+ switch (b)
+ {
+ case VFP_CPRC_SINGLE:
+ return 4;
+ case VFP_CPRC_DOUBLE:
+ return 8;
+ case VFP_CPRC_VEC64:
+ return 8;
+ case VFP_CPRC_VEC128:
+ return 16;
+ default:
+ internal_error (__FILE__, __LINE__, _("Invalid VFP CPRC type: %d."),
+ (int) b);
+ }
+}
+
+/* The character ('s', 'd' or 'q') for the type of VFP register used
+ for passing base type B. */
+
+static int
+arm_vfp_cprc_reg_char (enum arm_vfp_cprc_base_type b)
+{
+ switch (b)
+ {
+ case VFP_CPRC_SINGLE:
+ return 's';
+ case VFP_CPRC_DOUBLE:
+ return 'd';
+ case VFP_CPRC_VEC64:
+ return 'd';
+ case VFP_CPRC_VEC128:
+ return 'q';
+ default:
+ internal_error (__FILE__, __LINE__, _("Invalid VFP CPRC type: %d."),
+ (int) b);
+ }
+}
+
+/* Determine whether T may be part of a candidate for passing and
+ returning in VFP registers, ignoring the limit on the total number
+ of components. If *BASE_TYPE is VFP_CPRC_UNKNOWN, set it to the
+ classification of the first valid component found; if it is not
+ VFP_CPRC_UNKNOWN, all components must have the same classification
+ as *BASE_TYPE. If it is found that T contains a type not permitted
+ for passing and returning in VFP registers, a type differently
+ classified from *BASE_TYPE, or two types differently classified
+ from each other, return -1, otherwise return the total number of
+ base-type elements found (possibly 0 in an empty structure or
+ array). Vectors and complex types are not currently supported,
+ matching the generic AAPCS support. */
+
+static int
+arm_vfp_cprc_sub_candidate (struct type *t,
+ enum arm_vfp_cprc_base_type *base_type)
+{
+ t = check_typedef (t);
+ switch (TYPE_CODE (t))
+ {
+ case TYPE_CODE_FLT:
+ switch (TYPE_LENGTH (t))
+ {
+ case 4:
+ if (*base_type == VFP_CPRC_UNKNOWN)
+ *base_type = VFP_CPRC_SINGLE;
+ else if (*base_type != VFP_CPRC_SINGLE)
+ return -1;
+ return 1;
+
+ case 8:
+ if (*base_type == VFP_CPRC_UNKNOWN)
+ *base_type = VFP_CPRC_DOUBLE;
+ else if (*base_type != VFP_CPRC_DOUBLE)
+ return -1;
+ return 1;
+
+ default:
+ return -1;
+ }
+ break;
+
+ case TYPE_CODE_ARRAY:
+ {
+ int count;
+ unsigned unitlen;
+ count = arm_vfp_cprc_sub_candidate (TYPE_TARGET_TYPE (t), base_type);
+ if (count == -1)
+ return -1;
+ if (TYPE_LENGTH (t) == 0)
+ {
+ gdb_assert (count == 0);
+ return 0;
+ }
+ else if (count == 0)
+ return -1;
+ unitlen = arm_vfp_cprc_unit_length (*base_type);
+ gdb_assert ((TYPE_LENGTH (t) % unitlen) == 0);
+ return TYPE_LENGTH (t) / unitlen;
+ }
+ break;
+
+ case TYPE_CODE_STRUCT:
+ {
+ int count = 0;
+ unsigned unitlen;
+ int i;
+ for (i = 0; i < TYPE_NFIELDS (t); i++)
+ {
+ int sub_count = arm_vfp_cprc_sub_candidate (TYPE_FIELD_TYPE (t, i),
+ base_type);
+ if (sub_count == -1)
+ return -1;
+ count += sub_count;
+ }
+ if (TYPE_LENGTH (t) == 0)
+ {
+ gdb_assert (count == 0);
+ return 0;
+ }
+ else if (count == 0)
+ return -1;
+ unitlen = arm_vfp_cprc_unit_length (*base_type);
+ if (TYPE_LENGTH (t) != unitlen * count)
+ return -1;
+ return count;
+ }
+
+ case TYPE_CODE_UNION:
+ {
+ int count = 0;
+ unsigned unitlen;
+ int i;
+ for (i = 0; i < TYPE_NFIELDS (t); i++)
+ {
+ int sub_count = arm_vfp_cprc_sub_candidate (TYPE_FIELD_TYPE (t, i),
+ base_type);
+ if (sub_count == -1)
+ return -1;
+ count = (count > sub_count ? count : sub_count);
+ }
+ if (TYPE_LENGTH (t) == 0)
+ {
+ gdb_assert (count == 0);
+ return 0;
+ }
+ else if (count == 0)
+ return -1;
+ unitlen = arm_vfp_cprc_unit_length (*base_type);
+ if (TYPE_LENGTH (t) != unitlen * count)
+ return -1;
+ return count;
+ }
+
+ default:
+ break;
+ }
+
+ return -1;
+}
+
+/* Determine whether T is a VFP co-processor register candidate (CPRC)
+ if passed to or returned from a non-variadic function with the VFP
+ ABI in effect. Return 1 if it is, 0 otherwise. If it is, set
+ *BASE_TYPE to the base type for T and *COUNT to the number of
+ elements of that base type before returning. */
+
+static int
+arm_vfp_call_candidate (struct type *t, enum arm_vfp_cprc_base_type *base_type,
+ int *count)
+{
+ enum arm_vfp_cprc_base_type b = VFP_CPRC_UNKNOWN;
+ int c = arm_vfp_cprc_sub_candidate (t, &b);
+ if (c <= 0 || c > 4)
+ return 0;
+ *base_type = b;
+ *count = c;
+ return 1;
+}
+
+/* Return 1 if the VFP ABI should be used for passing arguments to and
+ returning values from a function of type FUNC_TYPE, 0
+ otherwise. */
+
+static int
+arm_vfp_abi_for_function (struct gdbarch *gdbarch, struct type *func_type)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ /* Variadic functions always use the base ABI. Assume that functions
+ without debug info are not variadic. */
+ if (func_type && TYPE_VARARGS (check_typedef (func_type)))
+ return 0;
+ /* The VFP ABI is only supported as a variant of AAPCS. */
+ if (tdep->arm_abi != ARM_ABI_AAPCS)
+ return 0;
+ return gdbarch_tdep (gdbarch)->fp_model == ARM_FLOAT_VFP;
+}
+
+/* We currently only support passing parameters in integer registers, which
+ conforms with GCC's default model, and VFP argument passing following
+ the VFP variant of AAPCS. Several other variants exist and
+ we should probably support some of them based on the selected ABI. */
+
+static CORE_ADDR
+arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
+ struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
+ struct value **args, CORE_ADDR sp, int struct_return,
+ CORE_ADDR struct_addr)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ int argnum;
+ int argreg;
+ int nstack;
+ struct stack_item *si = NULL;
+ int use_vfp_abi;
+ struct type *ftype;
+ unsigned vfp_regs_free = (1 << 16) - 1;
+
+ /* Determine the type of this function and whether the VFP ABI
+ applies. */
+ ftype = check_typedef (value_type (function));
+ if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
+ ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
+ use_vfp_abi = arm_vfp_abi_for_function (gdbarch, ftype);
+
+ /* Set the return address. For the ARM, the return breakpoint is
+ always at BP_ADDR. */
+ if (arm_pc_is_thumb (gdbarch, bp_addr))
+ bp_addr |= 1;
+ regcache_cooked_write_unsigned (regcache, ARM_LR_REGNUM, bp_addr);
+
+ /* Walk through the list of args and determine how large a temporary
+ stack is required. Need to take care here as structs may be
+ passed on the stack, and we have to push them. */
+ nstack = 0;
+
+ argreg = ARM_A1_REGNUM;
+ nstack = 0;
+
+ /* The struct_return pointer occupies the first parameter
+ passing register. */
+ if (struct_return)
+ {
+ if (arm_debug)
+ fprintf_unfiltered (gdb_stdlog, "struct return in %s = %s\n",
+ gdbarch_register_name (gdbarch, argreg),
+ paddress (gdbarch, struct_addr));
+ regcache_cooked_write_unsigned (regcache, argreg, struct_addr);
+ argreg++;
+ }
+
+ for (argnum = 0; argnum < nargs; argnum++)
+ {
+ int len;
+ struct type *arg_type;
+ struct type *target_type;
+ enum type_code typecode;
+ const bfd_byte *val;
+ int align;
+ enum arm_vfp_cprc_base_type vfp_base_type;
+ int vfp_base_count;
+ int may_use_core_reg = 1;
+
+ arg_type = check_typedef (value_type (args[argnum]));
+ len = TYPE_LENGTH (arg_type);
+ target_type = TYPE_TARGET_TYPE (arg_type);
+ typecode = TYPE_CODE (arg_type);
+ val = value_contents (args[argnum]);
+
+ align = arm_type_align (arg_type);
+ /* Round alignment up to a whole number of words. */
+ align = (align + INT_REGISTER_SIZE - 1) & ~(INT_REGISTER_SIZE - 1);
+ /* Different ABIs have different maximum alignments. */
+ if (gdbarch_tdep (gdbarch)->arm_abi == ARM_ABI_APCS)
+ {
+ /* The APCS ABI only requires word alignment. */
+ align = INT_REGISTER_SIZE;
+ }
+ else
+ {
+ /* The AAPCS requires at most doubleword alignment. */
+ if (align > INT_REGISTER_SIZE * 2)
+ align = INT_REGISTER_SIZE * 2;
+ }
+
+ if (use_vfp_abi
+ && arm_vfp_call_candidate (arg_type, &vfp_base_type,
+ &vfp_base_count))
+ {
+ int regno;
+ int unit_length;
+ int shift;
+ unsigned mask;
+
+ /* Because this is a CPRC it cannot go in a core register or
+ cause a core register to be skipped for alignment.
+ Either it goes in VFP registers and the rest of this loop
+ iteration is skipped for this argument, or it goes on the
+ stack (and the stack alignment code is correct for this
+ case). */
+ may_use_core_reg = 0;
+
+ unit_length = arm_vfp_cprc_unit_length (vfp_base_type);
+ shift = unit_length / 4;
+ mask = (1 << (shift * vfp_base_count)) - 1;
+ for (regno = 0; regno < 16; regno += shift)
+ if (((vfp_regs_free >> regno) & mask) == mask)
+ break;
+
+ if (regno < 16)
+ {
+ int reg_char;
+ int reg_scaled;
+ int i;
+
+ vfp_regs_free &= ~(mask << regno);
+ reg_scaled = regno / shift;
+ reg_char = arm_vfp_cprc_reg_char (vfp_base_type);
+ for (i = 0; i < vfp_base_count; i++)
+ {
+ char name_buf[4];
+ int regnum;
+ if (reg_char == 'q')
+ arm_neon_quad_write (gdbarch, regcache, reg_scaled + i,
+ val + i * unit_length);
+ else
+ {
+ sprintf (name_buf, "%c%d", reg_char, reg_scaled + i);
+ regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
+ strlen (name_buf));
+ regcache_cooked_write (regcache, regnum,
+ val + i * unit_length);
+ }
+ }
+ continue;
+ }
+ else
+ {
+ /* This CPRC could not go in VFP registers, so all VFP
+ registers are now marked as used. */
+ vfp_regs_free = 0;
+ }
+ }
+
+ /* Push stack padding for dowubleword alignment. */
+ if (nstack & (align - 1))
+ {
+ si = push_stack_item (si, val, INT_REGISTER_SIZE);
+ nstack += INT_REGISTER_SIZE;
+ }
+
+ /* Doubleword aligned quantities must go in even register pairs. */
+ if (may_use_core_reg
+ && argreg <= ARM_LAST_ARG_REGNUM
+ && align > INT_REGISTER_SIZE
+ && argreg & 1)
+ argreg++;
+
+ /* If the argument is a pointer to a function, and it is a
+ Thumb function, create a LOCAL copy of the value and set
+ the THUMB bit in it. */
+ if (TYPE_CODE_PTR == typecode
+ && target_type != NULL
+ && TYPE_CODE_FUNC == TYPE_CODE (check_typedef (target_type)))
+ {
+ CORE_ADDR regval = extract_unsigned_integer (val, len, byte_order);
+ if (arm_pc_is_thumb (gdbarch, regval))
+ {
+ bfd_byte *copy = alloca (len);
+ store_unsigned_integer (copy, len, byte_order,
+ MAKE_THUMB_ADDR (regval));
+ val = copy;
+ }
+ }
+
+ /* Copy the argument to general registers or the stack in
+ register-sized pieces. Large arguments are split between
+ registers and stack. */
+ while (len > 0)
+ {
+ int partial_len = len < INT_REGISTER_SIZE ? len : INT_REGISTER_SIZE;
+
+ if (may_use_core_reg && argreg <= ARM_LAST_ARG_REGNUM)
+ {
+ /* The argument is being passed in a general purpose
+ register. */
+ CORE_ADDR regval
+ = extract_unsigned_integer (val, partial_len, byte_order);
+ if (byte_order == BFD_ENDIAN_BIG)
+ regval <<= (INT_REGISTER_SIZE - partial_len) * 8;
+ if (arm_debug)
+ fprintf_unfiltered (gdb_stdlog, "arg %d in %s = 0x%s\n",
+ argnum,
+ gdbarch_register_name
+ (gdbarch, argreg),
+ phex (regval, INT_REGISTER_SIZE));
+ regcache_cooked_write_unsigned (regcache, argreg, regval);
+ argreg++;
+ }
+ else
+ {
+ /* Push the arguments onto the stack. */
+ if (arm_debug)
+ fprintf_unfiltered (gdb_stdlog, "arg %d @ sp + %d\n",
+ argnum, nstack);
+ si = push_stack_item (si, val, INT_REGISTER_SIZE);
+ nstack += INT_REGISTER_SIZE;
+ }
+
+ len -= partial_len;
+ val += partial_len;
+ }
+ }
+ /* If we have an odd number of words to push, then decrement the stack
+ by one word now, so first stack argument will be dword aligned. */
+ if (nstack & 4)
+ sp -= 4;
+
+ while (si)
+ {
+ sp -= si->len;
+ write_memory (sp, si->data, si->len);
+ si = pop_stack_item (si);
+ }
+
+ /* Finally, update teh SP register. */
+ regcache_cooked_write_unsigned (regcache, ARM_SP_REGNUM, sp);
+
+ return sp;
+}
+
+
+/* Always align the frame to an 8-byte boundary. This is required on
+ some platforms and harmless on the rest. */
+
+static CORE_ADDR
+arm_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
+{
+ /* Align the stack to eight bytes. */
+ return sp & ~ (CORE_ADDR) 7;
+}
+
+static void
+print_fpu_flags (int flags)
+{
+ if (flags & (1 << 0))
+ fputs ("IVO ", stdout);
+ if (flags & (1 << 1))
+ fputs ("DVZ ", stdout);
+ if (flags & (1 << 2))
+ fputs ("OFL ", stdout);
+ if (flags & (1 << 3))
+ fputs ("UFL ", stdout);
+ if (flags & (1 << 4))
+ fputs ("INX ", stdout);
+ putchar ('\n');
+}
+
+/* Print interesting information about the floating point processor
+ (if present) or emulator. */
+static void
+arm_print_float_info (struct gdbarch *gdbarch, struct ui_file *file,
+ struct frame_info *frame, const char *args)
+{
+ unsigned long status = get_frame_register_unsigned (frame, ARM_FPS_REGNUM);
+ int type;
+
+ type = (status >> 24) & 127;
+ if (status & (1 << 31))
+ printf (_("Hardware FPU type %d\n"), type);
+ else
+ printf (_("Software FPU type %d\n"), type);
+ /* i18n: [floating point unit] mask */
+ fputs (_("mask: "), stdout);
+ print_fpu_flags (status >> 16);
+ /* i18n: [floating point unit] flags */
+ fputs (_("flags: "), stdout);
+ print_fpu_flags (status);
+}
+
+/* Construct the ARM extended floating point type. */
+static struct type *
+arm_ext_type (struct gdbarch *gdbarch)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (!tdep->arm_ext_type)
+ tdep->arm_ext_type
+ = arch_float_type (gdbarch, -1, "builtin_type_arm_ext",
+ floatformats_arm_ext);
+
+ return tdep->arm_ext_type;
+}
+
+static struct type *
+arm_neon_double_type (struct gdbarch *gdbarch)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->neon_double_type == NULL)
+ {
+ struct type *t, *elem;
+
+ t = arch_composite_type (gdbarch, "__gdb_builtin_type_neon_d",
+ TYPE_CODE_UNION);
+ elem = builtin_type (gdbarch)->builtin_uint8;
+ append_composite_type_field (t, "u8", init_vector_type (elem, 8));
+ elem = builtin_type (gdbarch)->builtin_uint16;
+ append_composite_type_field (t, "u16", init_vector_type (elem, 4));
+ elem = builtin_type (gdbarch)->builtin_uint32;
+ append_composite_type_field (t, "u32", init_vector_type (elem, 2));
+ elem = builtin_type (gdbarch)->builtin_uint64;
+ append_composite_type_field (t, "u64", elem);
+ elem = builtin_type (gdbarch)->builtin_float;
+ append_composite_type_field (t, "f32", init_vector_type (elem, 2));
+ elem = builtin_type (gdbarch)->builtin_double;
+ append_composite_type_field (t, "f64", elem);
+
+ TYPE_VECTOR (t) = 1;
+ TYPE_NAME (t) = "neon_d";
+ tdep->neon_double_type = t;
+ }
+
+ return tdep->neon_double_type;
+}
+
+/* FIXME: The vector types are not correctly ordered on big-endian
+ targets. Just as s0 is the low bits of d0, d0[0] is also the low
+ bits of d0 - regardless of what unit size is being held in d0. So
+ the offset of the first uint8 in d0 is 7, but the offset of the
+ first float is 4. This code works as-is for little-endian
+ targets. */
+
+static struct type *
+arm_neon_quad_type (struct gdbarch *gdbarch)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->neon_quad_type == NULL)
+ {
+ struct type *t, *elem;
+
+ t = arch_composite_type (gdbarch, "__gdb_builtin_type_neon_q",
+ TYPE_CODE_UNION);
+ elem = builtin_type (gdbarch)->builtin_uint8;
+ append_composite_type_field (t, "u8", init_vector_type (elem, 16));
+ elem = builtin_type (gdbarch)->builtin_uint16;
+ append_composite_type_field (t, "u16", init_vector_type (elem, 8));
+ elem = builtin_type (gdbarch)->builtin_uint32;
+ append_composite_type_field (t, "u32", init_vector_type (elem, 4));
+ elem = builtin_type (gdbarch)->builtin_uint64;
+ append_composite_type_field (t, "u64", init_vector_type (elem, 2));
+ elem = builtin_type (gdbarch)->builtin_float;
+ append_composite_type_field (t, "f32", init_vector_type (elem, 4));
+ elem = builtin_type (gdbarch)->builtin_double;
+ append_composite_type_field (t, "f64", init_vector_type (elem, 2));
+
+ TYPE_VECTOR (t) = 1;
+ TYPE_NAME (t) = "neon_q";
+ tdep->neon_quad_type = t;
+ }
+
+ return tdep->neon_quad_type;
+}
+
+/* Return the GDB type object for the "standard" data type of data in
+ register N. */
+
+static struct type *
+arm_register_type (struct gdbarch *gdbarch, int regnum)
+{
+ int num_regs = gdbarch_num_regs (gdbarch);
+
+ if (gdbarch_tdep (gdbarch)->have_vfp_pseudos
+ && regnum >= num_regs && regnum < num_regs + 32)
+ return builtin_type (gdbarch)->builtin_float;
+
+ if (gdbarch_tdep (gdbarch)->have_neon_pseudos
+ && regnum >= num_regs + 32 && regnum < num_regs + 32 + 16)
+ return arm_neon_quad_type (gdbarch);
+
+ /* If the target description has register information, we are only
+ in this function so that we can override the types of
+ double-precision registers for NEON. */
+ if (tdesc_has_registers (gdbarch_target_desc (gdbarch)))
+ {
+ struct type *t = tdesc_register_type (gdbarch, regnum);
+
+ if (regnum >= ARM_D0_REGNUM && regnum < ARM_D0_REGNUM + 32
+ && TYPE_CODE (t) == TYPE_CODE_FLT
+ && gdbarch_tdep (gdbarch)->have_neon)
+ return arm_neon_double_type (gdbarch);
+ else
+ return t;
+ }
+
+ if (regnum >= ARM_F0_REGNUM && regnum < ARM_F0_REGNUM + NUM_FREGS)
+ {
+ if (!gdbarch_tdep (gdbarch)->have_fpa_registers)
+ return builtin_type (gdbarch)->builtin_void;
+
+ return arm_ext_type (gdbarch);
+ }
+ else if (regnum == ARM_SP_REGNUM)
+ return builtin_type (gdbarch)->builtin_data_ptr;
+ else if (regnum == ARM_PC_REGNUM)
+ return builtin_type (gdbarch)->builtin_func_ptr;
+ else if (regnum >= ARRAY_SIZE (arm_register_names))
+ /* These registers are only supported on targets which supply
+ an XML description. */
+ return builtin_type (gdbarch)->builtin_int0;
+ else
+ return builtin_type (gdbarch)->builtin_uint32;
+}
+
+/* Map a DWARF register REGNUM onto the appropriate GDB register
+ number. */
+
+static int
+arm_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
+{
+ /* Core integer regs. */
+ if (reg >= 0 && reg <= 15)
+ return reg;
+
+ /* Legacy FPA encoding. These were once used in a way which
+ overlapped with VFP register numbering, so their use is
+ discouraged, but GDB doesn't support the ARM toolchain
+ which used them for VFP. */
+ if (reg >= 16 && reg <= 23)
+ return ARM_F0_REGNUM + reg - 16;
+
+ /* New assignments for the FPA registers. */
+ if (reg >= 96 && reg <= 103)
+ return ARM_F0_REGNUM + reg - 96;
+
+ /* WMMX register assignments. */
+ if (reg >= 104 && reg <= 111)
+ return ARM_WCGR0_REGNUM + reg - 104;
+
+ if (reg >= 112 && reg <= 127)
+ return ARM_WR0_REGNUM + reg - 112;
+
+ if (reg >= 192 && reg <= 199)
+ return ARM_WC0_REGNUM + reg - 192;
+
+ /* VFP v2 registers. A double precision value is actually
+ in d1 rather than s2, but the ABI only defines numbering
+ for the single precision registers. This will "just work"
+ in GDB for little endian targets (we'll read eight bytes,
+ starting in s0 and then progressing to s1), but will be
+ reversed on big endian targets with VFP. This won't
+ be a problem for the new Neon quad registers; you're supposed
+ to use DW_OP_piece for those. */
+ if (reg >= 64 && reg <= 95)
+ {
+ char name_buf[4];
+
+ sprintf (name_buf, "s%d", reg - 64);
+ return user_reg_map_name_to_regnum (gdbarch, name_buf,
+ strlen (name_buf));
+ }
+
+ /* VFP v3 / Neon registers. This range is also used for VFP v2
+ registers, except that it now describes d0 instead of s0. */
+ if (reg >= 256 && reg <= 287)
+ {
+ char name_buf[4];
+
+ sprintf (name_buf, "d%d", reg - 256);
+ return user_reg_map_name_to_regnum (gdbarch, name_buf,
+ strlen (name_buf));
+ }
+
+ return -1;
+}
+
+/* Map GDB internal REGNUM onto the Arm simulator register numbers. */
+static int
+arm_register_sim_regno (struct gdbarch *gdbarch, int regnum)
+{
+ int reg = regnum;
+ gdb_assert (reg >= 0 && reg < gdbarch_num_regs (gdbarch));
+
+ if (regnum >= ARM_WR0_REGNUM && regnum <= ARM_WR15_REGNUM)
+ return regnum - ARM_WR0_REGNUM + SIM_ARM_IWMMXT_COP0R0_REGNUM;
+
+ if (regnum >= ARM_WC0_REGNUM && regnum <= ARM_WC7_REGNUM)
+ return regnum - ARM_WC0_REGNUM + SIM_ARM_IWMMXT_COP1R0_REGNUM;
+
+ if (regnum >= ARM_WCGR0_REGNUM && regnum <= ARM_WCGR7_REGNUM)
+ return regnum - ARM_WCGR0_REGNUM + SIM_ARM_IWMMXT_COP1R8_REGNUM;
+
+ if (reg < NUM_GREGS)
+ return SIM_ARM_R0_REGNUM + reg;
+ reg -= NUM_GREGS;
+
+ if (reg < NUM_FREGS)
+ return SIM_ARM_FP0_REGNUM + reg;
+ reg -= NUM_FREGS;
+
+ if (reg < NUM_SREGS)
+ return SIM_ARM_FPS_REGNUM + reg;
+ reg -= NUM_SREGS;
+
+ internal_error (__FILE__, __LINE__, _("Bad REGNUM %d"), regnum);
+}
+
+/* NOTE: cagney/2001-08-20: Both convert_from_extended() and
+ convert_to_extended() use floatformat_arm_ext_littlebyte_bigword.
+ It is thought that this is is the floating-point register format on
+ little-endian systems. */
+
+static void
+convert_from_extended (const struct floatformat *fmt, const void *ptr,
+ void *dbl, int endianess)
+{
+ DOUBLEST d;
+
+ if (endianess == BFD_ENDIAN_BIG)
+ floatformat_to_doublest (&floatformat_arm_ext_big, ptr, &d);
+ else
+ floatformat_to_doublest (&floatformat_arm_ext_littlebyte_bigword,
+ ptr, &d);
+ floatformat_from_doublest (fmt, &d, dbl);
+}
+
+static void
+convert_to_extended (const struct floatformat *fmt, void *dbl, const void *ptr,
+ int endianess)
+{
+ DOUBLEST d;
+
+ floatformat_to_doublest (fmt, ptr, &d);
+ if (endianess == BFD_ENDIAN_BIG)
+ floatformat_from_doublest (&floatformat_arm_ext_big, &d, dbl);
+ else
+ floatformat_from_doublest (&floatformat_arm_ext_littlebyte_bigword,
+ &d, dbl);
+}
+
+static int
+condition_true (unsigned long cond, unsigned long status_reg)
+{
+ if (cond == INST_AL || cond == INST_NV)
+ return 1;
+
+ switch (cond)
+ {
+ case INST_EQ:
+ return ((status_reg & FLAG_Z) != 0);
+ case INST_NE:
+ return ((status_reg & FLAG_Z) == 0);
+ case INST_CS:
+ return ((status_reg & FLAG_C) != 0);
+ case INST_CC:
+ return ((status_reg & FLAG_C) == 0);
+ case INST_MI:
+ return ((status_reg & FLAG_N) != 0);
+ case INST_PL:
+ return ((status_reg & FLAG_N) == 0);
+ case INST_VS:
+ return ((status_reg & FLAG_V) != 0);
+ case INST_VC:
+ return ((status_reg & FLAG_V) == 0);
+ case INST_HI:
+ return ((status_reg & (FLAG_C | FLAG_Z)) == FLAG_C);
+ case INST_LS:
+ return ((status_reg & (FLAG_C | FLAG_Z)) != FLAG_C);
+ case INST_GE:
+ return (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0));
+ case INST_LT:
+ return (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0));
+ case INST_GT:
+ return (((status_reg & FLAG_Z) == 0)
+ && (((status_reg & FLAG_N) == 0)
+ == ((status_reg & FLAG_V) == 0)));
+ case INST_LE:
+ return (((status_reg & FLAG_Z) != 0)
+ || (((status_reg & FLAG_N) == 0)
+ != ((status_reg & FLAG_V) == 0)));
+ }
+ return 1;
+}
+
+static unsigned long
+shifted_reg_val (struct frame_info *frame, unsigned long inst, int carry,
+ unsigned long pc_val, unsigned long status_reg)
+{
+ unsigned long res, shift;
+ int rm = bits (inst, 0, 3);
+ unsigned long shifttype = bits (inst, 5, 6);
+
+ if (bit (inst, 4))
+ {
+ int rs = bits (inst, 8, 11);
+ shift = (rs == 15 ? pc_val + 8
+ : get_frame_register_unsigned (frame, rs)) & 0xFF;
+ }
+ else
+ shift = bits (inst, 7, 11);
+
+ res = (rm == ARM_PC_REGNUM
+ ? (pc_val + (bit (inst, 4) ? 12 : 8))
+ : get_frame_register_unsigned (frame, rm));
+
+ switch (shifttype)
+ {
+ case 0: /* LSL */
+ res = shift >= 32 ? 0 : res << shift;
+ break;
+
+ case 1: /* LSR */
+ res = shift >= 32 ? 0 : res >> shift;
+ break;
+
+ case 2: /* ASR */
+ if (shift >= 32)
+ shift = 31;
+ res = ((res & 0x80000000L)
+ ? ~((~res) >> shift) : res >> shift);
+ break;
+
+ case 3: /* ROR/RRX */
+ shift &= 31;
+ if (shift == 0)
+ res = (res >> 1) | (carry ? 0x80000000L : 0);
+ else
+ res = (res >> shift) | (res << (32 - shift));
+ break;
+ }
+
+ return res & 0xffffffff;
+}
+
+/* Return number of 1-bits in VAL. */
+
+static int
+bitcount (unsigned long val)
+{
+ int nbits;
+ for (nbits = 0; val != 0; nbits++)
+ val &= val - 1; /* Delete rightmost 1-bit in val. */
+ return nbits;
+}
+
+/* Return the size in bytes of the complete Thumb instruction whose
+ first halfword is INST1. */
+
+static int
+thumb_insn_size (unsigned short inst1)
+{
+ if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
+ return 4;
+ else
+ return 2;
+}
+
+static int
+thumb_advance_itstate (unsigned int itstate)
+{
+ /* Preserve IT[7:5], the first three bits of the condition. Shift
+ the upcoming condition flags left by one bit. */
+ itstate = (itstate & 0xe0) | ((itstate << 1) & 0x1f);
+
+ /* If we have finished the IT block, clear the state. */
+ if ((itstate & 0x0f) == 0)
+ itstate = 0;
+
+ return itstate;
+}
+
+/* Find the next PC after the current instruction executes. In some
+ cases we can not statically determine the answer (see the IT state
+ handling in this function); in that case, a breakpoint may be
+ inserted in addition to the returned PC, which will be used to set
+ another breakpoint by our caller. */
+
+static CORE_ADDR
+thumb_get_next_pc_raw (struct frame_info *frame, CORE_ADDR pc)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct address_space *aspace = get_frame_address_space (frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned long pc_val = ((unsigned long) pc) + 4; /* PC after prefetch */
+ unsigned short inst1;
+ CORE_ADDR nextpc = pc + 2; /* Default is next instruction. */
+ unsigned long offset;
+ ULONGEST status, itstate;
+
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+ pc_val = MAKE_THUMB_ADDR (pc_val);
+
+ inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+
+ /* Thumb-2 conditional execution support. There are eight bits in
+ the CPSR which describe conditional execution state. Once
+ reconstructed (they're in a funny order), the low five bits
+ describe the low bit of the condition for each instruction and
+ how many instructions remain. The high three bits describe the
+ base condition. One of the low four bits will be set if an IT
+ block is active. These bits read as zero on earlier
+ processors. */
+ status = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
+ itstate = ((status >> 8) & 0xfc) | ((status >> 25) & 0x3);
+
+ /* If-Then handling. On GNU/Linux, where this routine is used, we
+ use an undefined instruction as a breakpoint. Unlike BKPT, IT
+ can disable execution of the undefined instruction. So we might
+ miss the breakpoint if we set it on a skipped conditional
+ instruction. Because conditional instructions can change the
+ flags, affecting the execution of further instructions, we may
+ need to set two breakpoints. */
+
+ if (gdbarch_tdep (gdbarch)->thumb2_breakpoint != NULL)
+ {
+ if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
+ {
+ /* An IT instruction. Because this instruction does not
+ modify the flags, we can accurately predict the next
+ executed instruction. */
+ itstate = inst1 & 0x00ff;
+ pc += thumb_insn_size (inst1);
+
+ while (itstate != 0 && ! condition_true (itstate >> 4, status))
+ {
+ inst1 = read_memory_unsigned_integer (pc, 2,
+ byte_order_for_code);
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+ }
+
+ return MAKE_THUMB_ADDR (pc);
+ }
+ else if (itstate != 0)
+ {
+ /* We are in a conditional block. Check the condition. */
+ if (! condition_true (itstate >> 4, status))
+ {
+ /* Advance to the next executed instruction. */
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+
+ while (itstate != 0 && ! condition_true (itstate >> 4, status))
+ {
+ inst1 = read_memory_unsigned_integer (pc, 2,
+ byte_order_for_code);
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+ }
+
+ return MAKE_THUMB_ADDR (pc);
+ }
+ else if ((itstate & 0x0f) == 0x08)
+ {
+ /* This is the last instruction of the conditional
+ block, and it is executed. We can handle it normally
+ because the following instruction is not conditional,
+ and we must handle it normally because it is
+ permitted to branch. Fall through. */
+ }
+ else
+ {
+ int cond_negated;
+
+ /* There are conditional instructions after this one.
+ If this instruction modifies the flags, then we can
+ not predict what the next executed instruction will
+ be. Fortunately, this instruction is architecturally
+ forbidden to branch; we know it will fall through.
+ Start by skipping past it. */
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+
+ /* Set a breakpoint on the following instruction. */
+ gdb_assert ((itstate & 0x0f) != 0);
+ arm_insert_single_step_breakpoint (gdbarch, aspace,
+ MAKE_THUMB_ADDR (pc));
+ cond_negated = (itstate >> 4) & 1;
+
+ /* Skip all following instructions with the same
+ condition. If there is a later instruction in the IT
+ block with the opposite condition, set the other
+ breakpoint there. If not, then set a breakpoint on
+ the instruction after the IT block. */
+ do
+ {
+ inst1 = read_memory_unsigned_integer (pc, 2,
+ byte_order_for_code);
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+ }
+ while (itstate != 0 && ((itstate >> 4) & 1) == cond_negated);
+
+ return MAKE_THUMB_ADDR (pc);
+ }
+ }
+ }
+ else if (itstate & 0x0f)
+ {
+ /* We are in a conditional block. Check the condition. */
+ int cond = itstate >> 4;
+
+ if (! condition_true (cond, status))
+ /* Advance to the next instruction. All the 32-bit
+ instructions share a common prefix. */
+ return MAKE_THUMB_ADDR (pc + thumb_insn_size (inst1));
+
+ /* Otherwise, handle the instruction normally. */
+ }
+
+ if ((inst1 & 0xff00) == 0xbd00) /* pop {rlist, pc} */
+ {
+ CORE_ADDR sp;
+
+ /* Fetch the saved PC from the stack. It's stored above
+ all of the other registers. */
+ offset = bitcount (bits (inst1, 0, 7)) * INT_REGISTER_SIZE;
+ sp = get_frame_register_unsigned (frame, ARM_SP_REGNUM);
+ nextpc = read_memory_unsigned_integer (sp + offset, 4, byte_order);
+ }
+ else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */
+ {
+ unsigned long cond = bits (inst1, 8, 11);
+ if (cond == 0x0f) /* 0x0f = SWI */
+ {
+ struct gdbarch_tdep *tdep;
+ tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->syscall_next_pc != NULL)
+ nextpc = tdep->syscall_next_pc (frame);
+
+ }
+ else if (cond != 0x0f && condition_true (cond, status))
+ nextpc = pc_val + (sbits (inst1, 0, 7) << 1);
+ }
+ else if ((inst1 & 0xf800) == 0xe000) /* unconditional branch */
+ {
+ nextpc = pc_val + (sbits (inst1, 0, 10) << 1);
+ }
+ else if (thumb_insn_size (inst1) == 4) /* 32-bit instruction */
+ {
+ unsigned short inst2;
+ inst2 = read_memory_unsigned_integer (pc + 2, 2, byte_order_for_code);
+
+ /* Default to the next instruction. */
+ nextpc = pc + 4;
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+
+ if ((inst1 & 0xf800) == 0xf000 && (inst2 & 0x8000) == 0x8000)
+ {
+ /* Branches and miscellaneous control instructions. */
+
+ if ((inst2 & 0x1000) != 0 || (inst2 & 0xd001) == 0xc000)
+ {
+ /* B, BL, BLX. */
+ int j1, j2, imm1, imm2;
+
+ imm1 = sbits (inst1, 0, 10);
+ imm2 = bits (inst2, 0, 10);
+ j1 = bit (inst2, 13);
+ j2 = bit (inst2, 11);
+
+ offset = ((imm1 << 12) + (imm2 << 1));
+ offset ^= ((!j2) << 22) | ((!j1) << 23);
+
+ nextpc = pc_val + offset;
+ /* For BLX make sure to clear the low bits. */
+ if (bit (inst2, 12) == 0)
+ nextpc = nextpc & 0xfffffffc;
+ }
+ else if (inst1 == 0xf3de && (inst2 & 0xff00) == 0x3f00)
+ {
+ /* SUBS PC, LR, #imm8. */
+ nextpc = get_frame_register_unsigned (frame, ARM_LR_REGNUM);
+ nextpc -= inst2 & 0x00ff;
+ }
+ else if ((inst2 & 0xd000) == 0x8000 && (inst1 & 0x0380) != 0x0380)
+ {
+ /* Conditional branch. */
+ if (condition_true (bits (inst1, 6, 9), status))
+ {
+ int sign, j1, j2, imm1, imm2;
+
+ sign = sbits (inst1, 10, 10);
+ imm1 = bits (inst1, 0, 5);
+ imm2 = bits (inst2, 0, 10);
+ j1 = bit (inst2, 13);
+ j2 = bit (inst2, 11);
+
+ offset = (sign << 20) + (j2 << 19) + (j1 << 18);
+ offset += (imm1 << 12) + (imm2 << 1);
+
+ nextpc = pc_val + offset;
+ }
+ }
+ }
+ else if ((inst1 & 0xfe50) == 0xe810)
+ {
+ /* Load multiple or RFE. */
+ int rn, offset, load_pc = 1;
+
+ rn = bits (inst1, 0, 3);
+ if (bit (inst1, 7) && !bit (inst1, 8))
+ {
+ /* LDMIA or POP */
+ if (!bit (inst2, 15))
+ load_pc = 0;
+ offset = bitcount (inst2) * 4 - 4;
+ }
+ else if (!bit (inst1, 7) && bit (inst1, 8))
+ {
+ /* LDMDB */
+ if (!bit (inst2, 15))
+ load_pc = 0;
+ offset = -4;
+ }
+ else if (bit (inst1, 7) && bit (inst1, 8))
+ {
+ /* RFEIA */
+ offset = 0;
+ }
+ else if (!bit (inst1, 7) && !bit (inst1, 8))
+ {
+ /* RFEDB */
+ offset = -8;
+ }
+ else
+ load_pc = 0;
+
+ if (load_pc)
+ {
+ CORE_ADDR addr = get_frame_register_unsigned (frame, rn);
+ nextpc = get_frame_memory_unsigned (frame, addr + offset, 4);
+ }
+ }
+ else if ((inst1 & 0xffef) == 0xea4f && (inst2 & 0xfff0) == 0x0f00)
+ {
+ /* MOV PC or MOVS PC. */
+ nextpc = get_frame_register_unsigned (frame, bits (inst2, 0, 3));
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+ }
+ else if ((inst1 & 0xff70) == 0xf850 && (inst2 & 0xf000) == 0xf000)
+ {
+ /* LDR PC. */
+ CORE_ADDR base;
+ int rn, load_pc = 1;
+
+ rn = bits (inst1, 0, 3);
+ base = get_frame_register_unsigned (frame, rn);
+ if (rn == ARM_PC_REGNUM)
+ {
+ base = (base + 4) & ~(CORE_ADDR) 0x3;
+ if (bit (inst1, 7))
+ base += bits (inst2, 0, 11);
+ else
+ base -= bits (inst2, 0, 11);
+ }
+ else if (bit (inst1, 7))
+ base += bits (inst2, 0, 11);
+ else if (bit (inst2, 11))
+ {
+ if (bit (inst2, 10))
+ {
+ if (bit (inst2, 9))
+ base += bits (inst2, 0, 7);
+ else
+ base -= bits (inst2, 0, 7);
+ }
+ }
+ else if ((inst2 & 0x0fc0) == 0x0000)
+ {
+ int shift = bits (inst2, 4, 5), rm = bits (inst2, 0, 3);
+ base += get_frame_register_unsigned (frame, rm) << shift;
+ }
+ else
+ /* Reserved. */
+ load_pc = 0;
+
+ if (load_pc)
+ nextpc = get_frame_memory_unsigned (frame, base, 4);
+ }
+ else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
+ {
+ /* TBB. */
+ CORE_ADDR tbl_reg, table, offset, length;
+
+ tbl_reg = bits (inst1, 0, 3);
+ if (tbl_reg == 0x0f)
+ table = pc + 4; /* Regcache copy of PC isn't right yet. */
+ else
+ table = get_frame_register_unsigned (frame, tbl_reg);
+
+ offset = get_frame_register_unsigned (frame, bits (inst2, 0, 3));
+ length = 2 * get_frame_memory_unsigned (frame, table + offset, 1);
+ nextpc = pc_val + length;
+ }
+ else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf010)
+ {
+ /* TBH. */
+ CORE_ADDR tbl_reg, table, offset, length;
+
+ tbl_reg = bits (inst1, 0, 3);
+ if (tbl_reg == 0x0f)
+ table = pc + 4; /* Regcache copy of PC isn't right yet. */
+ else
+ table = get_frame_register_unsigned (frame, tbl_reg);
+
+ offset = 2 * get_frame_register_unsigned (frame, bits (inst2, 0, 3));
+ length = 2 * get_frame_memory_unsigned (frame, table + offset, 2);
+ nextpc = pc_val + length;
+ }
+ }
+ else if ((inst1 & 0xff00) == 0x4700) /* bx REG, blx REG */
+ {
+ if (bits (inst1, 3, 6) == 0x0f)
+ nextpc = pc_val;
+ else
+ nextpc = get_frame_register_unsigned (frame, bits (inst1, 3, 6));
+ }
+ else if ((inst1 & 0xff87) == 0x4687) /* mov pc, REG */
+ {
+ if (bits (inst1, 3, 6) == 0x0f)
+ nextpc = pc_val;
+ else
+ nextpc = get_frame_register_unsigned (frame, bits (inst1, 3, 6));
+
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+ }
+ else if ((inst1 & 0xf500) == 0xb100)
+ {
+ /* CBNZ or CBZ. */
+ int imm = (bit (inst1, 9) << 6) + (bits (inst1, 3, 7) << 1);
+ ULONGEST reg = get_frame_register_unsigned (frame, bits (inst1, 0, 2));
+
+ if (bit (inst1, 11) && reg != 0)
+ nextpc = pc_val + imm;
+ else if (!bit (inst1, 11) && reg == 0)
+ nextpc = pc_val + imm;
+ }
+ return nextpc;
+}
+
+/* Get the raw next address. PC is the current program counter, in
+ FRAME, which is assumed to be executing in ARM mode.
+
+ The value returned has the execution state of the next instruction
+ encoded in it. Use IS_THUMB_ADDR () to see whether the instruction is
+ in Thumb-State, and gdbarch_addr_bits_remove () to get the plain memory
+ address. */
+
+static CORE_ADDR
+arm_get_next_pc_raw (struct frame_info *frame, CORE_ADDR pc)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned long pc_val;
+ unsigned long this_instr;
+ unsigned long status;
+ CORE_ADDR nextpc;
+
+ pc_val = (unsigned long) pc;
+ this_instr = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
+
+ status = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
+ nextpc = (CORE_ADDR) (pc_val + 4); /* Default case */
+
+ if (bits (this_instr, 28, 31) == INST_NV)
+ switch (bits (this_instr, 24, 27))
+ {
+ case 0xa:
+ case 0xb:
+ {
+ /* Branch with Link and change to Thumb. */
+ nextpc = BranchDest (pc, this_instr);
+ nextpc |= bit (this_instr, 24) << 1;
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+ break;
+ }
+ case 0xc:
+ case 0xd:
+ case 0xe:
+ /* Coprocessor register transfer. */
+ if (bits (this_instr, 12, 15) == 15)
+ error (_("Invalid update to pc in instruction"));
+ break;
+ }
+ else if (condition_true (bits (this_instr, 28, 31), status))
+ {
+ switch (bits (this_instr, 24, 27))
+ {
+ case 0x0:
+ case 0x1: /* data processing */
+ case 0x2:
+ case 0x3:
+ {
+ unsigned long operand1, operand2, result = 0;
+ unsigned long rn;
+ int c;
+
+ if (bits (this_instr, 12, 15) != 15)
+ break;
+
+ if (bits (this_instr, 22, 25) == 0
+ && bits (this_instr, 4, 7) == 9) /* multiply */
+ error (_("Invalid update to pc in instruction"));
+
+ /* BX <reg>, BLX <reg> */
+ if (bits (this_instr, 4, 27) == 0x12fff1
+ || bits (this_instr, 4, 27) == 0x12fff3)
+ {
+ rn = bits (this_instr, 0, 3);
+ nextpc = ((rn == ARM_PC_REGNUM)
+ ? (pc_val + 8)
+ : get_frame_register_unsigned (frame, rn));
+
+ return nextpc;
+ }
+
+ /* Multiply into PC. */
+ c = (status & FLAG_C) ? 1 : 0;
+ rn = bits (this_instr, 16, 19);
+ operand1 = ((rn == ARM_PC_REGNUM)
+ ? (pc_val + 8)
+ : get_frame_register_unsigned (frame, rn));
+
+ if (bit (this_instr, 25))
+ {
+ unsigned long immval = bits (this_instr, 0, 7);
+ unsigned long rotate = 2 * bits (this_instr, 8, 11);
+ operand2 = ((immval >> rotate) | (immval << (32 - rotate)))
+ & 0xffffffff;
+ }
+ else /* operand 2 is a shifted register. */
+ operand2 = shifted_reg_val (frame, this_instr, c,
+ pc_val, status);
+
+ switch (bits (this_instr, 21, 24))
+ {
+ case 0x0: /*and */
+ result = operand1 & operand2;
+ break;
+
+ case 0x1: /*eor */
+ result = operand1 ^ operand2;
+ break;
+
+ case 0x2: /*sub */
+ result = operand1 - operand2;
+ break;
+
+ case 0x3: /*rsb */
+ result = operand2 - operand1;
+ break;
+
+ case 0x4: /*add */
+ result = operand1 + operand2;
+ break;
+
+ case 0x5: /*adc */
+ result = operand1 + operand2 + c;
+ break;
+
+ case 0x6: /*sbc */
+ result = operand1 - operand2 + c;
+ break;
+
+ case 0x7: /*rsc */
+ result = operand2 - operand1 + c;
+ break;
+
+ case 0x8:
+ case 0x9:
+ case 0xa:
+ case 0xb: /* tst, teq, cmp, cmn */
+ result = (unsigned long) nextpc;
+ break;
+
+ case 0xc: /*orr */
+ result = operand1 | operand2;
+ break;
+
+ case 0xd: /*mov */
+ /* Always step into a function. */
+ result = operand2;
+ break;
+
+ case 0xe: /*bic */
+ result = operand1 & ~operand2;
+ break;
+
+ case 0xf: /*mvn */
+ result = ~operand2;
+ break;
+ }
+
+ /* In 26-bit APCS the bottom two bits of the result are
+ ignored, and we always end up in ARM state. */
+ if (!arm_apcs_32)
+ nextpc = arm_addr_bits_remove (gdbarch, result);
+ else
+ nextpc = result;
+
+ break;
+ }
+
+ case 0x4:
+ case 0x5: /* data transfer */
+ case 0x6:
+ case 0x7:
+ if (bit (this_instr, 20))
+ {
+ /* load */
+ if (bits (this_instr, 12, 15) == 15)
+ {
+ /* rd == pc */
+ unsigned long rn;
+ unsigned long base;
+
+ if (bit (this_instr, 22))
+ error (_("Invalid update to pc in instruction"));
+
+ /* byte write to PC */
+ rn = bits (this_instr, 16, 19);
+ base = ((rn == ARM_PC_REGNUM)
+ ? (pc_val + 8)
+ : get_frame_register_unsigned (frame, rn));
+
+ if (bit (this_instr, 24))
+ {
+ /* pre-indexed */
+ int c = (status & FLAG_C) ? 1 : 0;
+ unsigned long offset =
+ (bit (this_instr, 25)
+ ? shifted_reg_val (frame, this_instr, c, pc_val, status)
+ : bits (this_instr, 0, 11));
+
+ if (bit (this_instr, 23))
+ base += offset;
+ else
+ base -= offset;
+ }
+ nextpc =
+ (CORE_ADDR) read_memory_unsigned_integer ((CORE_ADDR) base,
+ 4, byte_order);
+ }
+ }
+ break;
+
+ case 0x8:
+ case 0x9: /* block transfer */
+ if (bit (this_instr, 20))
+ {
+ /* LDM */
+ if (bit (this_instr, 15))
+ {
+ /* loading pc */
+ int offset = 0;
+ unsigned long rn_val
+ = get_frame_register_unsigned (frame,
+ bits (this_instr, 16, 19));
+
+ if (bit (this_instr, 23))
+ {
+ /* up */
+ unsigned long reglist = bits (this_instr, 0, 14);
+ offset = bitcount (reglist) * 4;
+ if (bit (this_instr, 24)) /* pre */
+ offset += 4;
+ }
+ else if (bit (this_instr, 24))
+ offset = -4;
+
+ nextpc =
+ (CORE_ADDR) read_memory_unsigned_integer ((CORE_ADDR)
+ (rn_val + offset),
+ 4, byte_order);
+ }
+ }
+ break;
+
+ case 0xb: /* branch & link */
+ case 0xa: /* branch */
+ {
+ nextpc = BranchDest (pc, this_instr);
+ break;
+ }
+
+ case 0xc:
+ case 0xd:
+ case 0xe: /* coproc ops */
+ break;
+ case 0xf: /* SWI */
+ {
+ struct gdbarch_tdep *tdep;
+ tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->syscall_next_pc != NULL)
+ nextpc = tdep->syscall_next_pc (frame);
+
+ }
+ break;
+
+ default:
+ fprintf_filtered (gdb_stderr, _("Bad bit-field extraction\n"));
+ return (pc);
+ }
+ }
+
+ return nextpc;
+}
+
+/* Determine next PC after current instruction executes. Will call either
+ arm_get_next_pc_raw or thumb_get_next_pc_raw. Error out if infinite
+ loop is detected. */
+
+CORE_ADDR
+arm_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
+{
+ CORE_ADDR nextpc;
+
+ if (arm_frame_is_thumb (frame))
+ {
+ nextpc = thumb_get_next_pc_raw (frame, pc);
+ if (nextpc == MAKE_THUMB_ADDR (pc))
+ error (_("Infinite loop detected"));
+ }
+ else
+ {
+ nextpc = arm_get_next_pc_raw (frame, pc);
+ if (nextpc == pc)
+ error (_("Infinite loop detected"));
+ }
+
+ return nextpc;
+}
+
+/* Like insert_single_step_breakpoint, but make sure we use a breakpoint
+ of the appropriate mode (as encoded in the PC value), even if this
+ differs from what would be expected according to the symbol tables. */
+
+void
+arm_insert_single_step_breakpoint (struct gdbarch *gdbarch,
+ struct address_space *aspace,
+ CORE_ADDR pc)
+{
+ struct cleanup *old_chain
+ = make_cleanup_restore_integer (&arm_override_mode);
+
+ arm_override_mode = IS_THUMB_ADDR (pc);
+ pc = gdbarch_addr_bits_remove (gdbarch, pc);
+
+ insert_single_step_breakpoint (gdbarch, aspace, pc);
+
+ do_cleanups (old_chain);
+}
+
+/* single_step() is called just before we want to resume the inferior,
+ if we want to single-step it but there is no hardware or kernel
+ single-step support. We find the target of the coming instruction
+ and breakpoint it. */
+
+int
+arm_software_single_step (struct frame_info *frame)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct address_space *aspace = get_frame_address_space (frame);
+ CORE_ADDR next_pc = arm_get_next_pc (frame, get_frame_pc (frame));
+
+ arm_insert_single_step_breakpoint (gdbarch, aspace, next_pc);
+
+ return 1;
+}
+
+/* Given BUF, which is OLD_LEN bytes ending at ENDADDR, expand
+ the buffer to be NEW_LEN bytes ending at ENDADDR. Return
+ NULL if an error occurs. BUF is freed. */
+
+static gdb_byte *
+extend_buffer_earlier (gdb_byte *buf, CORE_ADDR endaddr,
+ int old_len, int new_len)
+{
+ gdb_byte *new_buf, *middle;
+ int bytes_to_read = new_len - old_len;
+
+ new_buf = xmalloc (new_len);
+ memcpy (new_buf + bytes_to_read, buf, old_len);
+ xfree (buf);
+ if (target_read_memory (endaddr - new_len, new_buf, bytes_to_read) != 0)
+ {
+ xfree (new_buf);
+ return NULL;
+ }
+ return new_buf;
+}
+
+/* An IT block is at most the 2-byte IT instruction followed by
+ four 4-byte instructions. The furthest back we must search to
+ find an IT block that affects the current instruction is thus
+ 2 + 3 * 4 == 14 bytes. */
+#define MAX_IT_BLOCK_PREFIX 14
+
+/* Use a quick scan if there are more than this many bytes of
+ code. */
+#define IT_SCAN_THRESHOLD 32
+
+/* Adjust a breakpoint's address to move breakpoints out of IT blocks.
+ A breakpoint in an IT block may not be hit, depending on the
+ condition flags. */
+static CORE_ADDR
+arm_adjust_breakpoint_address (struct gdbarch *gdbarch, CORE_ADDR bpaddr)
+{
+ gdb_byte *buf;
+ char map_type;
+ CORE_ADDR boundary, func_start;
+ int buf_len, buf2_len;
+ enum bfd_endian order = gdbarch_byte_order_for_code (gdbarch);
+ int i, any, last_it, last_it_count;
+
+ /* If we are using BKPT breakpoints, none of this is necessary. */
+ if (gdbarch_tdep (gdbarch)->thumb2_breakpoint == NULL)
+ return bpaddr;
+
+ /* ARM mode does not have this problem. */
+ if (!arm_pc_is_thumb (gdbarch, bpaddr))
+ return bpaddr;
+
+ /* We are setting a breakpoint in Thumb code that could potentially
+ contain an IT block. The first step is to find how much Thumb
+ code there is; we do not need to read outside of known Thumb
+ sequences. */
+ map_type = arm_find_mapping_symbol (bpaddr, &boundary);
+ if (map_type == 0)
+ /* Thumb-2 code must have mapping symbols to have a chance. */
+ return bpaddr;
+
+ bpaddr = gdbarch_addr_bits_remove (gdbarch, bpaddr);
+
+ if (find_pc_partial_function (bpaddr, NULL, &func_start, NULL)
+ && func_start > boundary)
+ boundary = func_start;
+
+ /* Search for a candidate IT instruction. We have to do some fancy
+ footwork to distinguish a real IT instruction from the second
+ half of a 32-bit instruction, but there is no need for that if
+ there's no candidate. */
+ buf_len = min (bpaddr - boundary, MAX_IT_BLOCK_PREFIX);
+ if (buf_len == 0)
+ /* No room for an IT instruction. */
+ return bpaddr;
+
+ buf = xmalloc (buf_len);
+ if (target_read_memory (bpaddr - buf_len, buf, buf_len) != 0)
+ return bpaddr;
+ any = 0;
+ for (i = 0; i < buf_len; i += 2)
+ {
+ unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
+ if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
+ {
+ any = 1;
+ break;
+ }
+ }
+ if (any == 0)
+ {
+ xfree (buf);
+ return bpaddr;
+ }
+
+ /* OK, the code bytes before this instruction contain at least one
+ halfword which resembles an IT instruction. We know that it's
+ Thumb code, but there are still two possibilities. Either the
+ halfword really is an IT instruction, or it is the second half of
+ a 32-bit Thumb instruction. The only way we can tell is to
+ scan forwards from a known instruction boundary. */
+ if (bpaddr - boundary > IT_SCAN_THRESHOLD)
+ {
+ int definite;
+
+ /* There's a lot of code before this instruction. Start with an
+ optimistic search; it's easy to recognize halfwords that can
+ not be the start of a 32-bit instruction, and use that to
+ lock on to the instruction boundaries. */
+ buf = extend_buffer_earlier (buf, bpaddr, buf_len, IT_SCAN_THRESHOLD);
+ if (buf == NULL)
+ return bpaddr;
+ buf_len = IT_SCAN_THRESHOLD;
+
+ definite = 0;
+ for (i = 0; i < buf_len - sizeof (buf) && ! definite; i += 2)
+ {
+ unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
+ if (thumb_insn_size (inst1) == 2)
+ {
+ definite = 1;
+ break;
+ }
+ }
+
+ /* At this point, if DEFINITE, BUF[I] is the first place we
+ are sure that we know the instruction boundaries, and it is far
+ enough from BPADDR that we could not miss an IT instruction
+ affecting BPADDR. If ! DEFINITE, give up - start from a
+ known boundary. */
+ if (! definite)
+ {
+ buf = extend_buffer_earlier (buf, bpaddr, buf_len,
+ bpaddr - boundary);
+ if (buf == NULL)
+ return bpaddr;
+ buf_len = bpaddr - boundary;
+ i = 0;
+ }
+ }
+ else
+ {
+ buf = extend_buffer_earlier (buf, bpaddr, buf_len, bpaddr - boundary);
+ if (buf == NULL)
+ return bpaddr;
+ buf_len = bpaddr - boundary;
+ i = 0;
+ }
+
+ /* Scan forwards. Find the last IT instruction before BPADDR. */
+ last_it = -1;
+ last_it_count = 0;
+ while (i < buf_len)
+ {
+ unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
+ last_it_count--;
+ if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
+ {
+ last_it = i;
+ if (inst1 & 0x0001)
+ last_it_count = 4;
+ else if (inst1 & 0x0002)
+ last_it_count = 3;
+ else if (inst1 & 0x0004)
+ last_it_count = 2;
+ else
+ last_it_count = 1;
+ }
+ i += thumb_insn_size (inst1);
+ }
+
+ xfree (buf);
+
+ if (last_it == -1)
+ /* There wasn't really an IT instruction after all. */
+ return bpaddr;
+
+ if (last_it_count < 1)
+ /* It was too far away. */
+ return bpaddr;
+
+ /* This really is a trouble spot. Move the breakpoint to the IT
+ instruction. */
+ return bpaddr - buf_len + last_it;
+}
+
+/* ARM displaced stepping support.
+
+ Generally ARM displaced stepping works as follows:
- return sp;
-}
+ 1. When an instruction is to be single-stepped, it is first decoded by
+ arm_process_displaced_insn (called from arm_displaced_step_copy_insn).
+ Depending on the type of instruction, it is then copied to a scratch
+ location, possibly in a modified form. The copy_* set of functions
+ performs such modification, as necessary. A breakpoint is placed after
+ the modified instruction in the scratch space to return control to GDB.
+ Note in particular that instructions which modify the PC will no longer
+ do so after modification.
+ 2. The instruction is single-stepped, by setting the PC to the scratch
+ location address, and resuming. Control returns to GDB when the
+ breakpoint is hit.
-/* Always align the frame to an 8-byte boundary. This is required on
- some platforms and harmless on the rest. */
+ 3. A cleanup function (cleanup_*) is called corresponding to the copy_*
+ function used for the current instruction. This function's job is to
+ put the CPU/memory state back to what it would have been if the
+ instruction had been executed unmodified in its original location. */
-static CORE_ADDR
-arm_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
-{
- /* Align the stack to eight bytes. */
- return sp & ~ (CORE_ADDR) 7;
-}
+/* NOP instruction (mov r0, r0). */
+#define ARM_NOP 0xe1a00000
+#define THUMB_NOP 0x4600
-static void
-print_fpu_flags (int flags)
-{
- if (flags & (1 << 0))
- fputs ("IVO ", stdout);
- if (flags & (1 << 1))
- fputs ("DVZ ", stdout);
- if (flags & (1 << 2))
- fputs ("OFL ", stdout);
- if (flags & (1 << 3))
- fputs ("UFL ", stdout);
- if (flags & (1 << 4))
- fputs ("INX ", stdout);
- putchar ('\n');
-}
+/* Helper for register reads for displaced stepping. In particular, this
+ returns the PC as it would be seen by the instruction at its original
+ location. */
-/* Print interesting information about the floating point processor
- (if present) or emulator. */
-static void
-arm_print_float_info (struct gdbarch *gdbarch, struct ui_file *file,
- struct frame_info *frame, const char *args)
+ULONGEST
+displaced_read_reg (struct regcache *regs, struct displaced_step_closure *dsc,
+ int regno)
{
- unsigned long status = get_frame_register_unsigned (frame, ARM_FPS_REGNUM);
- int type;
+ ULONGEST ret;
+ CORE_ADDR from = dsc->insn_addr;
- type = (status >> 24) & 127;
- if (status & (1 << 31))
- printf (_("Hardware FPU type %d\n"), type);
+ if (regno == ARM_PC_REGNUM)
+ {
+ /* Compute pipeline offset:
+ - When executing an ARM instruction, PC reads as the address of the
+ current instruction plus 8.
+ - When executing a Thumb instruction, PC reads as the address of the
+ current instruction plus 4. */
+
+ if (!dsc->is_thumb)
+ from += 8;
+ else
+ from += 4;
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: read pc value %.8lx\n",
+ (unsigned long) from);
+ return (ULONGEST) from;
+ }
else
- printf (_("Software FPU type %d\n"), type);
- /* i18n: [floating point unit] mask */
- fputs (_("mask: "), stdout);
- print_fpu_flags (status >> 16);
- /* i18n: [floating point unit] flags */
- fputs (_("flags: "), stdout);
- print_fpu_flags (status);
+ {
+ regcache_cooked_read_unsigned (regs, regno, &ret);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: read r%d value %.8lx\n",
+ regno, (unsigned long) ret);
+ return ret;
+ }
}
-/* Construct the ARM extended floating point type. */
-static struct type *
-arm_ext_type (struct gdbarch *gdbarch)
+static int
+displaced_in_arm_mode (struct regcache *regs)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ ULONGEST ps;
+ ULONGEST t_bit = arm_psr_thumb_bit (get_regcache_arch (regs));
- if (!tdep->arm_ext_type)
- tdep->arm_ext_type
- = arch_float_type (gdbarch, -1, "builtin_type_arm_ext",
- floatformats_arm_ext);
+ regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
- return tdep->arm_ext_type;
+ return (ps & t_bit) == 0;
}
-static struct type *
-arm_neon_double_type (struct gdbarch *gdbarch)
+/* Write to the PC as from a branch instruction. */
+
+static void
+branch_write_pc (struct regcache *regs, struct displaced_step_closure *dsc,
+ ULONGEST val)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ if (!dsc->is_thumb)
+ /* Note: If bits 0/1 are set, this branch would be unpredictable for
+ architecture versions < 6. */
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM,
+ val & ~(ULONGEST) 0x3);
+ else
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM,
+ val & ~(ULONGEST) 0x1);
+}
- if (tdep->neon_double_type == NULL)
- {
- struct type *t, *elem;
+/* Write to the PC as from a branch-exchange instruction. */
- t = arch_composite_type (gdbarch, "__gdb_builtin_type_neon_d",
- TYPE_CODE_UNION);
- elem = builtin_type (gdbarch)->builtin_uint8;
- append_composite_type_field (t, "u8", init_vector_type (elem, 8));
- elem = builtin_type (gdbarch)->builtin_uint16;
- append_composite_type_field (t, "u16", init_vector_type (elem, 4));
- elem = builtin_type (gdbarch)->builtin_uint32;
- append_composite_type_field (t, "u32", init_vector_type (elem, 2));
- elem = builtin_type (gdbarch)->builtin_uint64;
- append_composite_type_field (t, "u64", elem);
- elem = builtin_type (gdbarch)->builtin_float;
- append_composite_type_field (t, "f32", init_vector_type (elem, 2));
- elem = builtin_type (gdbarch)->builtin_double;
- append_composite_type_field (t, "f64", elem);
+static void
+bx_write_pc (struct regcache *regs, ULONGEST val)
+{
+ ULONGEST ps;
+ ULONGEST t_bit = arm_psr_thumb_bit (get_regcache_arch (regs));
- TYPE_VECTOR (t) = 1;
- TYPE_NAME (t) = "neon_d";
- tdep->neon_double_type = t;
- }
+ regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
- return tdep->neon_double_type;
+ if ((val & 1) == 1)
+ {
+ regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps | t_bit);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffe);
+ }
+ else if ((val & 2) == 0)
+ {
+ regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val);
+ }
+ else
+ {
+ /* Unpredictable behaviour. Try to do something sensible (switch to ARM
+ mode, align dest to 4 bytes). */
+ warning (_("Single-stepping BX to non-word-aligned ARM instruction."));
+ regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffc);
+ }
}
-/* FIXME: The vector types are not correctly ordered on big-endian
- targets. Just as s0 is the low bits of d0, d0[0] is also the low
- bits of d0 - regardless of what unit size is being held in d0. So
- the offset of the first uint8 in d0 is 7, but the offset of the
- first float is 4. This code works as-is for little-endian
- targets. */
+/* Write to the PC as if from a load instruction. */
-static struct type *
-arm_neon_quad_type (struct gdbarch *gdbarch)
+static void
+load_write_pc (struct regcache *regs, struct displaced_step_closure *dsc,
+ ULONGEST val)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
-
- if (tdep->neon_quad_type == NULL)
- {
- struct type *t, *elem;
-
- t = arch_composite_type (gdbarch, "__gdb_builtin_type_neon_q",
- TYPE_CODE_UNION);
- elem = builtin_type (gdbarch)->builtin_uint8;
- append_composite_type_field (t, "u8", init_vector_type (elem, 16));
- elem = builtin_type (gdbarch)->builtin_uint16;
- append_composite_type_field (t, "u16", init_vector_type (elem, 8));
- elem = builtin_type (gdbarch)->builtin_uint32;
- append_composite_type_field (t, "u32", init_vector_type (elem, 4));
- elem = builtin_type (gdbarch)->builtin_uint64;
- append_composite_type_field (t, "u64", init_vector_type (elem, 2));
- elem = builtin_type (gdbarch)->builtin_float;
- append_composite_type_field (t, "f32", init_vector_type (elem, 4));
- elem = builtin_type (gdbarch)->builtin_double;
- append_composite_type_field (t, "f64", init_vector_type (elem, 2));
+ if (DISPLACED_STEPPING_ARCH_VERSION >= 5)
+ bx_write_pc (regs, val);
+ else
+ branch_write_pc (regs, dsc, val);
+}
- TYPE_VECTOR (t) = 1;
- TYPE_NAME (t) = "neon_q";
- tdep->neon_quad_type = t;
- }
+/* Write to the PC as if from an ALU instruction. */
- return tdep->neon_quad_type;
+static void
+alu_write_pc (struct regcache *regs, struct displaced_step_closure *dsc,
+ ULONGEST val)
+{
+ if (DISPLACED_STEPPING_ARCH_VERSION >= 7 && !dsc->is_thumb)
+ bx_write_pc (regs, val);
+ else
+ branch_write_pc (regs, dsc, val);
}
-/* Return the GDB type object for the "standard" data type of data in
- register N. */
+/* Helper for writing to registers for displaced stepping. Writing to the PC
+ has a varying effects depending on the instruction which does the write:
+ this is controlled by the WRITE_PC argument. */
-static struct type *
-arm_register_type (struct gdbarch *gdbarch, int regnum)
+void
+displaced_write_reg (struct regcache *regs, struct displaced_step_closure *dsc,
+ int regno, ULONGEST val, enum pc_write_style write_pc)
{
- int num_regs = gdbarch_num_regs (gdbarch);
+ if (regno == ARM_PC_REGNUM)
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: writing pc %.8lx\n",
+ (unsigned long) val);
+ switch (write_pc)
+ {
+ case BRANCH_WRITE_PC:
+ branch_write_pc (regs, dsc, val);
+ break;
- if (gdbarch_tdep (gdbarch)->have_vfp_pseudos
- && regnum >= num_regs && regnum < num_regs + 32)
- return builtin_type (gdbarch)->builtin_float;
+ case BX_WRITE_PC:
+ bx_write_pc (regs, val);
+ break;
- if (gdbarch_tdep (gdbarch)->have_neon_pseudos
- && regnum >= num_regs + 32 && regnum < num_regs + 32 + 16)
- return arm_neon_quad_type (gdbarch);
+ case LOAD_WRITE_PC:
+ load_write_pc (regs, dsc, val);
+ break;
- /* If the target description has register information, we are only
- in this function so that we can override the types of
- double-precision registers for NEON. */
- if (tdesc_has_registers (gdbarch_target_desc (gdbarch)))
- {
- struct type *t = tdesc_register_type (gdbarch, regnum);
+ case ALU_WRITE_PC:
+ alu_write_pc (regs, dsc, val);
+ break;
- if (regnum >= ARM_D0_REGNUM && regnum < ARM_D0_REGNUM + 32
- && TYPE_CODE (t) == TYPE_CODE_FLT
- && gdbarch_tdep (gdbarch)->have_neon)
- return arm_neon_double_type (gdbarch);
- else
- return t;
- }
+ case CANNOT_WRITE_PC:
+ warning (_("Instruction wrote to PC in an unexpected way when "
+ "single-stepping"));
+ break;
- if (regnum >= ARM_F0_REGNUM && regnum < ARM_F0_REGNUM + NUM_FREGS)
- {
- if (!gdbarch_tdep (gdbarch)->have_fpa_registers)
- return builtin_type (gdbarch)->builtin_void;
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Invalid argument to displaced_write_reg"));
+ }
- return arm_ext_type (gdbarch);
+ dsc->wrote_to_pc = 1;
}
- else if (regnum == ARM_SP_REGNUM)
- return builtin_type (gdbarch)->builtin_data_ptr;
- else if (regnum == ARM_PC_REGNUM)
- return builtin_type (gdbarch)->builtin_func_ptr;
- else if (regnum >= ARRAY_SIZE (arm_register_names))
- /* These registers are only supported on targets which supply
- an XML description. */
- return builtin_type (gdbarch)->builtin_int0;
else
- return builtin_type (gdbarch)->builtin_uint32;
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: writing r%d value %.8lx\n",
+ regno, (unsigned long) val);
+ regcache_cooked_write_unsigned (regs, regno, val);
+ }
}
-/* Map a DWARF register REGNUM onto the appropriate GDB register
- number. */
+/* This function is used to concisely determine if an instruction INSN
+ references PC. Register fields of interest in INSN should have the
+ corresponding fields of BITMASK set to 0b1111. The function
+ returns return 1 if any of these fields in INSN reference the PC
+ (also 0b1111, r15), else it returns 0. */
static int
-arm_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
+insn_references_pc (uint32_t insn, uint32_t bitmask)
{
- /* Core integer regs. */
- if (reg >= 0 && reg <= 15)
- return reg;
-
- /* Legacy FPA encoding. These were once used in a way which
- overlapped with VFP register numbering, so their use is
- discouraged, but GDB doesn't support the ARM toolchain
- which used them for VFP. */
- if (reg >= 16 && reg <= 23)
- return ARM_F0_REGNUM + reg - 16;
-
- /* New assignments for the FPA registers. */
- if (reg >= 96 && reg <= 103)
- return ARM_F0_REGNUM + reg - 96;
-
- /* WMMX register assignments. */
- if (reg >= 104 && reg <= 111)
- return ARM_WCGR0_REGNUM + reg - 104;
+ uint32_t lowbit = 1;
- if (reg >= 112 && reg <= 127)
- return ARM_WR0_REGNUM + reg - 112;
+ while (bitmask != 0)
+ {
+ uint32_t mask;
- if (reg >= 192 && reg <= 199)
- return ARM_WC0_REGNUM + reg - 192;
+ for (; lowbit && (bitmask & lowbit) == 0; lowbit <<= 1)
+ ;
- /* VFP v2 registers. A double precision value is actually
- in d1 rather than s2, but the ABI only defines numbering
- for the single precision registers. This will "just work"
- in GDB for little endian targets (we'll read eight bytes,
- starting in s0 and then progressing to s1), but will be
- reversed on big endian targets with VFP. This won't
- be a problem for the new Neon quad registers; you're supposed
- to use DW_OP_piece for those. */
- if (reg >= 64 && reg <= 95)
- {
- char name_buf[4];
+ if (!lowbit)
+ break;
- sprintf (name_buf, "s%d", reg - 64);
- return user_reg_map_name_to_regnum (gdbarch, name_buf,
- strlen (name_buf));
- }
+ mask = lowbit * 0xf;
- /* VFP v3 / Neon registers. This range is also used for VFP v2
- registers, except that it now describes d0 instead of s0. */
- if (reg >= 256 && reg <= 287)
- {
- char name_buf[4];
+ if ((insn & mask) == mask)
+ return 1;
- sprintf (name_buf, "d%d", reg - 256);
- return user_reg_map_name_to_regnum (gdbarch, name_buf,
- strlen (name_buf));
+ bitmask &= ~mask;
}
- return -1;
+ return 0;
}
-/* Map GDB internal REGNUM onto the Arm simulator register numbers. */
+/* The simplest copy function. Many instructions have the same effect no
+ matter what address they are executed at: in those cases, use this. */
+
static int
-arm_register_sim_regno (struct gdbarch *gdbarch, int regnum)
+arm_copy_unmodified (struct gdbarch *gdbarch, uint32_t insn,
+ const char *iname, struct displaced_step_closure *dsc)
{
- int reg = regnum;
- gdb_assert (reg >= 0 && reg < gdbarch_num_regs (gdbarch));
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying insn %.8lx, "
+ "opcode/class '%s' unmodified\n", (unsigned long) insn,
+ iname);
- if (regnum >= ARM_WR0_REGNUM && regnum <= ARM_WR15_REGNUM)
- return regnum - ARM_WR0_REGNUM + SIM_ARM_IWMMXT_COP0R0_REGNUM;
+ dsc->modinsn[0] = insn;
- if (regnum >= ARM_WC0_REGNUM && regnum <= ARM_WC7_REGNUM)
- return regnum - ARM_WC0_REGNUM + SIM_ARM_IWMMXT_COP1R0_REGNUM;
+ return 0;
+}
- if (regnum >= ARM_WCGR0_REGNUM && regnum <= ARM_WCGR7_REGNUM)
- return regnum - ARM_WCGR0_REGNUM + SIM_ARM_IWMMXT_COP1R8_REGNUM;
+static int
+thumb_copy_unmodified_32bit (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, const char *iname,
+ struct displaced_step_closure *dsc)
+{
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying insn %.4x %.4x, "
+ "opcode/class '%s' unmodified\n", insn1, insn2,
+ iname);
- if (reg < NUM_GREGS)
- return SIM_ARM_R0_REGNUM + reg;
- reg -= NUM_GREGS;
+ dsc->modinsn[0] = insn1;
+ dsc->modinsn[1] = insn2;
+ dsc->numinsns = 2;
- if (reg < NUM_FREGS)
- return SIM_ARM_FP0_REGNUM + reg;
- reg -= NUM_FREGS;
+ return 0;
+}
- if (reg < NUM_SREGS)
- return SIM_ARM_FPS_REGNUM + reg;
- reg -= NUM_SREGS;
+/* Copy 16-bit Thumb(Thumb and 16-bit Thumb-2) instruction without any
+ modification. */
+static int
+thumb_copy_unmodified_16bit (struct gdbarch *gdbarch, unsigned int insn,
+ const char *iname,
+ struct displaced_step_closure *dsc)
+{
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying insn %.4x, "
+ "opcode/class '%s' unmodified\n", insn,
+ iname);
- internal_error (__FILE__, __LINE__, _("Bad REGNUM %d"), regnum);
+ dsc->modinsn[0] = insn;
+
+ return 0;
}
-/* NOTE: cagney/2001-08-20: Both convert_from_extended() and
- convert_to_extended() use floatformat_arm_ext_littlebyte_bigword.
- It is thought that this is is the floating-point register format on
- little-endian systems. */
+/* Preload instructions with immediate offset. */
static void
-convert_from_extended (const struct floatformat *fmt, const void *ptr,
- void *dbl, int endianess)
+cleanup_preload (struct gdbarch *gdbarch,
+ struct regcache *regs, struct displaced_step_closure *dsc)
{
- DOUBLEST d;
-
- if (endianess == BFD_ENDIAN_BIG)
- floatformat_to_doublest (&floatformat_arm_ext_big, ptr, &d);
- else
- floatformat_to_doublest (&floatformat_arm_ext_littlebyte_bigword,
- ptr, &d);
- floatformat_from_doublest (fmt, &d, dbl);
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
+ if (!dsc->u.preload.immed)
+ displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
}
static void
-convert_to_extended (const struct floatformat *fmt, void *dbl, const void *ptr,
- int endianess)
+install_preload (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc, unsigned int rn)
{
- DOUBLEST d;
+ ULONGEST rn_val;
+ /* Preload instructions:
- floatformat_to_doublest (fmt, ptr, &d);
- if (endianess == BFD_ENDIAN_BIG)
- floatformat_from_doublest (&floatformat_arm_ext_big, &d, dbl);
- else
- floatformat_from_doublest (&floatformat_arm_ext_littlebyte_bigword,
- &d, dbl);
+ {pli/pld} [rn, #+/-imm]
+ ->
+ {pli/pld} [r0, #+/-imm]. */
+
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
+ dsc->u.preload.immed = 1;
+
+ dsc->cleanup = &cleanup_preload;
}
static int
-condition_true (unsigned long cond, unsigned long status_reg)
+arm_copy_preload (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- if (cond == INST_AL || cond == INST_NV)
- return 1;
+ unsigned int rn = bits (insn, 16, 19);
- switch (cond)
- {
- case INST_EQ:
- return ((status_reg & FLAG_Z) != 0);
- case INST_NE:
- return ((status_reg & FLAG_Z) == 0);
- case INST_CS:
- return ((status_reg & FLAG_C) != 0);
- case INST_CC:
- return ((status_reg & FLAG_C) == 0);
- case INST_MI:
- return ((status_reg & FLAG_N) != 0);
- case INST_PL:
- return ((status_reg & FLAG_N) == 0);
- case INST_VS:
- return ((status_reg & FLAG_V) != 0);
- case INST_VC:
- return ((status_reg & FLAG_V) == 0);
- case INST_HI:
- return ((status_reg & (FLAG_C | FLAG_Z)) == FLAG_C);
- case INST_LS:
- return ((status_reg & (FLAG_C | FLAG_Z)) != FLAG_C);
- case INST_GE:
- return (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0));
- case INST_LT:
- return (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0));
- case INST_GT:
- return (((status_reg & FLAG_Z) == 0)
- && (((status_reg & FLAG_N) == 0)
- == ((status_reg & FLAG_V) == 0)));
- case INST_LE:
- return (((status_reg & FLAG_Z) != 0)
- || (((status_reg & FLAG_N) == 0)
- != ((status_reg & FLAG_V) == 0)));
- }
- return 1;
+ if (!insn_references_pc (insn, 0x000f0000ul))
+ return arm_copy_unmodified (gdbarch, insn, "preload", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying preload insn %.8lx\n",
+ (unsigned long) insn);
+
+ dsc->modinsn[0] = insn & 0xfff0ffff;
+
+ install_preload (gdbarch, regs, dsc, rn);
+
+ return 0;
}
-static unsigned long
-shifted_reg_val (struct frame_info *frame, unsigned long inst, int carry,
- unsigned long pc_val, unsigned long status_reg)
+static int
+thumb2_copy_preload (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2,
+ struct regcache *regs, struct displaced_step_closure *dsc)
{
- unsigned long res, shift;
- int rm = bits (inst, 0, 3);
- unsigned long shifttype = bits (inst, 5, 6);
+ unsigned int rn = bits (insn1, 0, 3);
+ unsigned int u_bit = bit (insn1, 7);
+ int imm12 = bits (insn2, 0, 11);
+ ULONGEST pc_val;
- if (bit (inst, 4))
- {
- int rs = bits (inst, 8, 11);
- shift = (rs == 15 ? pc_val + 8
- : get_frame_register_unsigned (frame, rs)) & 0xFF;
- }
- else
- shift = bits (inst, 7, 11);
+ if (rn != ARM_PC_REGNUM)
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "preload", dsc);
- res = (rm == 15
- ? (pc_val + (bit (inst, 4) ? 12 : 8))
- : get_frame_register_unsigned (frame, rm));
+ /* PC is only allowed to use in PLI (immediate,literal) Encoding T3, and
+ PLD (literal) Encoding T1. */
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying pld/pli pc (0x%x) %c imm12 %.4x\n",
+ (unsigned int) dsc->insn_addr, u_bit ? '+' : '-',
+ imm12);
- switch (shifttype)
- {
- case 0: /* LSL */
- res = shift >= 32 ? 0 : res << shift;
- break;
+ if (!u_bit)
+ imm12 = -1 * imm12;
- case 1: /* LSR */
- res = shift >= 32 ? 0 : res >> shift;
- break;
+ /* Rewrite instruction {pli/pld} PC imm12 into:
+ Prepare: tmp[0] <- r0, tmp[1] <- r1, r0 <- pc, r1 <- imm12
- case 2: /* ASR */
- if (shift >= 32)
- shift = 31;
- res = ((res & 0x80000000L)
- ? ~((~res) >> shift) : res >> shift);
- break;
+ {pli/pld} [r0, r1]
+
+ Cleanup: r0 <- tmp[0], r1 <- tmp[1]. */
- case 3: /* ROR/RRX */
- shift &= 31;
- if (shift == 0)
- res = (res >> 1) | (carry ? 0x80000000L : 0);
- else
- res = (res >> shift) | (res << (32 - shift));
- break;
- }
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
- return res & 0xffffffff;
-}
+ pc_val = displaced_read_reg (regs, dsc, ARM_PC_REGNUM);
-/* Return number of 1-bits in VAL. */
+ displaced_write_reg (regs, dsc, 0, pc_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, imm12, CANNOT_WRITE_PC);
+ dsc->u.preload.immed = 0;
-static int
-bitcount (unsigned long val)
-{
- int nbits;
- for (nbits = 0; val != 0; nbits++)
- val &= val - 1; /* Delete rightmost 1-bit in val. */
- return nbits;
+ /* {pli/pld} [r0, r1] */
+ dsc->modinsn[0] = insn1 & 0xfff0;
+ dsc->modinsn[1] = 0xf001;
+ dsc->numinsns = 2;
+
+ dsc->cleanup = &cleanup_preload;
+ return 0;
}
-/* Return the size in bytes of the complete Thumb instruction whose
- first halfword is INST1. */
+/* Preload instructions with register offset. */
-static int
-thumb_insn_size (unsigned short inst1)
+static void
+install_preload_reg(struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc, unsigned int rn,
+ unsigned int rm)
{
- if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
- return 4;
- else
- return 2;
+ ULONGEST rn_val, rm_val;
+
+ /* Preload register-offset instructions:
+
+ {pli/pld} [rn, rm {, shift}]
+ ->
+ {pli/pld} [r0, r1 {, shift}]. */
+
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ rm_val = displaced_read_reg (regs, dsc, rm);
+ displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, rm_val, CANNOT_WRITE_PC);
+ dsc->u.preload.immed = 0;
+
+ dsc->cleanup = &cleanup_preload;
}
static int
-thumb_advance_itstate (unsigned int itstate)
+arm_copy_preload_reg (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- /* Preserve IT[7:5], the first three bits of the condition. Shift
- the upcoming condition flags left by one bit. */
- itstate = (itstate & 0xe0) | ((itstate << 1) & 0x1f);
+ unsigned int rn = bits (insn, 16, 19);
+ unsigned int rm = bits (insn, 0, 3);
- /* If we have finished the IT block, clear the state. */
- if ((itstate & 0x0f) == 0)
- itstate = 0;
- return itstate;
+ if (!insn_references_pc (insn, 0x000f000ful))
+ return arm_copy_unmodified (gdbarch, insn, "preload reg", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying preload insn %.8lx\n",
+ (unsigned long) insn);
+
+ dsc->modinsn[0] = (insn & 0xfff0fff0) | 0x1;
+
+ install_preload_reg (gdbarch, regs, dsc, rn, rm);
+ return 0;
}
-/* Find the next PC after the current instruction executes. In some
- cases we can not statically determine the answer (see the IT state
- handling in this function); in that case, a breakpoint may be
- inserted in addition to the returned PC, which will be used to set
- another breakpoint by our caller. */
+/* Copy/cleanup coprocessor load and store instructions. */
-static CORE_ADDR
-thumb_get_next_pc_raw (struct frame_info *frame, CORE_ADDR pc, int insert_bkpt)
+static void
+cleanup_copro_load_store (struct gdbarch *gdbarch,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- struct gdbarch *gdbarch = get_frame_arch (frame);
- struct address_space *aspace = get_frame_address_space (frame);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- unsigned long pc_val = ((unsigned long) pc) + 4; /* PC after prefetch */
- unsigned short inst1;
- CORE_ADDR nextpc = pc + 2; /* Default is next instruction. */
- unsigned long offset;
- ULONGEST status, itstate;
+ ULONGEST rn_val = displaced_read_reg (regs, dsc, 0);
- nextpc = MAKE_THUMB_ADDR (nextpc);
- pc_val = MAKE_THUMB_ADDR (pc_val);
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
- inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+ if (dsc->u.ldst.writeback)
+ displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, LOAD_WRITE_PC);
+}
- /* Thumb-2 conditional execution support. There are eight bits in
- the CPSR which describe conditional execution state. Once
- reconstructed (they're in a funny order), the low five bits
- describe the low bit of the condition for each instruction and
- how many instructions remain. The high three bits describe the
- base condition. One of the low four bits will be set if an IT
- block is active. These bits read as zero on earlier
- processors. */
- status = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
- itstate = ((status >> 8) & 0xfc) | ((status >> 25) & 0x3);
+static void
+install_copro_load_store (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc,
+ int writeback, unsigned int rn)
+{
+ ULONGEST rn_val;
- /* If-Then handling. On GNU/Linux, where this routine is used, we
- use an undefined instruction as a breakpoint. Unlike BKPT, IT
- can disable execution of the undefined instruction. So we might
- miss the breakpoint if we set it on a skipped conditional
- instruction. Because conditional instructions can change the
- flags, affecting the execution of further instructions, we may
- need to set two breakpoints. */
+ /* Coprocessor load/store instructions:
- if (gdbarch_tdep (gdbarch)->thumb2_breakpoint != NULL)
- {
- if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
- {
- /* An IT instruction. Because this instruction does not
- modify the flags, we can accurately predict the next
- executed instruction. */
- itstate = inst1 & 0x00ff;
- pc += thumb_insn_size (inst1);
+ {stc/stc2} [<Rn>, #+/-imm] (and other immediate addressing modes)
+ ->
+ {stc/stc2} [r0, #+/-imm].
- while (itstate != 0 && ! condition_true (itstate >> 4, status))
- {
- inst1 = read_memory_unsigned_integer (pc, 2,
- byte_order_for_code);
- pc += thumb_insn_size (inst1);
- itstate = thumb_advance_itstate (itstate);
- }
+ ldc/ldc2 are handled identically. */
- return MAKE_THUMB_ADDR (pc);
- }
- else if (itstate != 0)
- {
- /* We are in a conditional block. Check the condition. */
- if (! condition_true (itstate >> 4, status))
- {
- /* Advance to the next executed instruction. */
- pc += thumb_insn_size (inst1);
- itstate = thumb_advance_itstate (itstate);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ /* PC should be 4-byte aligned. */
+ rn_val = rn_val & 0xfffffffc;
+ displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
- while (itstate != 0 && ! condition_true (itstate >> 4, status))
- {
- inst1 = read_memory_unsigned_integer (pc, 2,
- byte_order_for_code);
- pc += thumb_insn_size (inst1);
- itstate = thumb_advance_itstate (itstate);
- }
+ dsc->u.ldst.writeback = writeback;
+ dsc->u.ldst.rn = rn;
- return MAKE_THUMB_ADDR (pc);
- }
- else if ((itstate & 0x0f) == 0x08)
- {
- /* This is the last instruction of the conditional
- block, and it is executed. We can handle it normally
- because the following instruction is not conditional,
- and we must handle it normally because it is
- permitted to branch. Fall through. */
- }
- else
- {
- int cond_negated;
+ dsc->cleanup = &cleanup_copro_load_store;
+}
- /* There are conditional instructions after this one.
- If this instruction modifies the flags, then we can
- not predict what the next executed instruction will
- be. Fortunately, this instruction is architecturally
- forbidden to branch; we know it will fall through.
- Start by skipping past it. */
- pc += thumb_insn_size (inst1);
- itstate = thumb_advance_itstate (itstate);
+static int
+arm_copy_copro_load_store (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rn = bits (insn, 16, 19);
- /* Set a breakpoint on the following instruction. */
- gdb_assert ((itstate & 0x0f) != 0);
- if (insert_bkpt)
- insert_single_step_breakpoint (gdbarch, aspace, pc);
- cond_negated = (itstate >> 4) & 1;
+ if (!insn_references_pc (insn, 0x000f0000ul))
+ return arm_copy_unmodified (gdbarch, insn, "copro load/store", dsc);
- /* Skip all following instructions with the same
- condition. If there is a later instruction in the IT
- block with the opposite condition, set the other
- breakpoint there. If not, then set a breakpoint on
- the instruction after the IT block. */
- do
- {
- inst1 = read_memory_unsigned_integer (pc, 2,
- byte_order_for_code);
- pc += thumb_insn_size (inst1);
- itstate = thumb_advance_itstate (itstate);
- }
- while (itstate != 0 && ((itstate >> 4) & 1) == cond_negated);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying coprocessor "
+ "load/store insn %.8lx\n", (unsigned long) insn);
- return MAKE_THUMB_ADDR (pc);
- }
- }
- }
- else if (itstate & 0x0f)
- {
- /* We are in a conditional block. Check the condition. */
- int cond = itstate >> 4;
+ dsc->modinsn[0] = insn & 0xfff0ffff;
- if (! condition_true (cond, status))
- {
- /* Advance to the next instruction. All the 32-bit
- instructions share a common prefix. */
- if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
- return MAKE_THUMB_ADDR (pc + 4);
- else
- return MAKE_THUMB_ADDR (pc + 2);
- }
+ install_copro_load_store (gdbarch, regs, dsc, bit (insn, 25), rn);
- /* Otherwise, handle the instruction normally. */
- }
+ return 0;
+}
- if ((inst1 & 0xff00) == 0xbd00) /* pop {rlist, pc} */
- {
- CORE_ADDR sp;
+static int
+thumb2_copy_copro_load_store (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rn = bits (insn1, 0, 3);
- /* Fetch the saved PC from the stack. It's stored above
- all of the other registers. */
- offset = bitcount (bits (inst1, 0, 7)) * INT_REGISTER_SIZE;
- sp = get_frame_register_unsigned (frame, ARM_SP_REGNUM);
- nextpc = read_memory_unsigned_integer (sp + offset, 4, byte_order);
- }
- else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */
- {
- unsigned long cond = bits (inst1, 8, 11);
- if (cond == 0x0f) /* 0x0f = SWI */
- {
- struct gdbarch_tdep *tdep;
- tdep = gdbarch_tdep (gdbarch);
+ if (rn != ARM_PC_REGNUM)
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "copro load/store", dsc);
- if (tdep->syscall_next_pc != NULL)
- nextpc = tdep->syscall_next_pc (frame);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying coprocessor "
+ "load/store insn %.4x%.4x\n", insn1, insn2);
+
+ dsc->modinsn[0] = insn1 & 0xfff0;
+ dsc->modinsn[1] = insn2;
+ dsc->numinsns = 2;
+
+ /* This function is called for copying instruction LDC/LDC2/VLDR, which
+ doesn't support writeback, so pass 0. */
+ install_copro_load_store (gdbarch, regs, dsc, 0, rn);
+
+ return 0;
+}
+
+/* Clean up branch instructions (actually perform the branch, by setting
+ PC). */
+
+static void
+cleanup_branch (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM);
+ int branch_taken = condition_true (dsc->u.branch.cond, status);
+ enum pc_write_style write_pc = dsc->u.branch.exchange
+ ? BX_WRITE_PC : BRANCH_WRITE_PC;
+
+ if (!branch_taken)
+ return;
- }
- else if (cond != 0x0f && condition_true (cond, status))
- nextpc = pc_val + (sbits (inst1, 0, 7) << 1);
- }
- else if ((inst1 & 0xf800) == 0xe000) /* unconditional branch */
+ if (dsc->u.branch.link)
{
- nextpc = pc_val + (sbits (inst1, 0, 10) << 1);
+ /* The value of LR should be the next insn of current one. In order
+ not to confuse logic hanlding later insn `bx lr', if current insn mode
+ is Thumb, the bit 0 of LR value should be set to 1. */
+ ULONGEST next_insn_addr = dsc->insn_addr + dsc->insn_size;
+
+ if (dsc->is_thumb)
+ next_insn_addr |= 0x1;
+
+ displaced_write_reg (regs, dsc, ARM_LR_REGNUM, next_insn_addr,
+ CANNOT_WRITE_PC);
}
- else if ((inst1 & 0xe000) == 0xe000) /* 32-bit instruction */
- {
- unsigned short inst2;
- inst2 = read_memory_unsigned_integer (pc + 2, 2, byte_order_for_code);
- /* Default to the next instruction. */
- nextpc = pc + 4;
- nextpc = MAKE_THUMB_ADDR (nextpc);
+ displaced_write_reg (regs, dsc, ARM_PC_REGNUM, dsc->u.branch.dest, write_pc);
+}
- if ((inst1 & 0xf800) == 0xf000 && (inst2 & 0x8000) == 0x8000)
- {
- /* Branches and miscellaneous control instructions. */
+/* Copy B/BL/BLX instructions with immediate destinations. */
- if ((inst2 & 0x1000) != 0 || (inst2 & 0xd001) == 0xc000)
- {
- /* B, BL, BLX. */
- int j1, j2, imm1, imm2;
+static void
+install_b_bl_blx (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc,
+ unsigned int cond, int exchange, int link, long offset)
+{
+ /* Implement "BL<cond> <label>" as:
- imm1 = sbits (inst1, 0, 10);
- imm2 = bits (inst2, 0, 10);
- j1 = bit (inst2, 13);
- j2 = bit (inst2, 11);
+ Preparation: cond <- instruction condition
+ Insn: mov r0, r0 (nop)
+ Cleanup: if (condition true) { r14 <- pc; pc <- label }.
- offset = ((imm1 << 12) + (imm2 << 1));
- offset ^= ((!j2) << 22) | ((!j1) << 23);
+ B<cond> similar, but don't set r14 in cleanup. */
- nextpc = pc_val + offset;
- /* For BLX make sure to clear the low bits. */
- if (bit (inst2, 12) == 0)
- nextpc = nextpc & 0xfffffffc;
- }
- else if (inst1 == 0xf3de && (inst2 & 0xff00) == 0x3f00)
- {
- /* SUBS PC, LR, #imm8. */
- nextpc = get_frame_register_unsigned (frame, ARM_LR_REGNUM);
- nextpc -= inst2 & 0x00ff;
- }
- else if ((inst2 & 0xd000) == 0x8000 && (inst1 & 0x0380) != 0x0380)
- {
- /* Conditional branch. */
- if (condition_true (bits (inst1, 6, 9), status))
- {
- int sign, j1, j2, imm1, imm2;
+ dsc->u.branch.cond = cond;
+ dsc->u.branch.link = link;
+ dsc->u.branch.exchange = exchange;
- sign = sbits (inst1, 10, 10);
- imm1 = bits (inst1, 0, 5);
- imm2 = bits (inst2, 0, 10);
- j1 = bit (inst2, 13);
- j2 = bit (inst2, 11);
+ dsc->u.branch.dest = dsc->insn_addr;
+ if (link && exchange)
+ /* For BLX, offset is computed from the Align (PC, 4). */
+ dsc->u.branch.dest = dsc->u.branch.dest & 0xfffffffc;
- offset = (sign << 20) + (j2 << 19) + (j1 << 18);
- offset += (imm1 << 12) + (imm2 << 1);
+ if (dsc->is_thumb)
+ dsc->u.branch.dest += 4 + offset;
+ else
+ dsc->u.branch.dest += 8 + offset;
- nextpc = pc_val + offset;
- }
- }
- }
- else if ((inst1 & 0xfe50) == 0xe810)
- {
- /* Load multiple or RFE. */
- int rn, offset, load_pc = 1;
+ dsc->cleanup = &cleanup_branch;
+}
+static int
+arm_copy_b_bl_blx (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int cond = bits (insn, 28, 31);
+ int exchange = (cond == 0xf);
+ int link = exchange || bit (insn, 24);
+ long offset;
- rn = bits (inst1, 0, 3);
- if (bit (inst1, 7) && !bit (inst1, 8))
- {
- /* LDMIA or POP */
- if (!bit (inst2, 15))
- load_pc = 0;
- offset = bitcount (inst2) * 4 - 4;
- }
- else if (!bit (inst1, 7) && bit (inst1, 8))
- {
- /* LDMDB */
- if (!bit (inst2, 15))
- load_pc = 0;
- offset = -4;
- }
- else if (bit (inst1, 7) && bit (inst1, 8))
- {
- /* RFEIA */
- offset = 0;
- }
- else if (!bit (inst1, 7) && !bit (inst1, 8))
- {
- /* RFEDB */
- offset = -8;
- }
- else
- load_pc = 0;
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying %s immediate insn "
+ "%.8lx\n", (exchange) ? "blx" : (link) ? "bl" : "b",
+ (unsigned long) insn);
+ if (exchange)
+ /* For BLX, set bit 0 of the destination. The cleanup_branch function will
+ then arrange the switch into Thumb mode. */
+ offset = (bits (insn, 0, 23) << 2) | (bit (insn, 24) << 1) | 1;
+ else
+ offset = bits (insn, 0, 23) << 2;
- if (load_pc)
- {
- CORE_ADDR addr = get_frame_register_unsigned (frame, rn);
- nextpc = get_frame_memory_unsigned (frame, addr + offset, 4);
- }
- }
- else if ((inst1 & 0xffef) == 0xea4f && (inst2 & 0xfff0) == 0x0f00)
- {
- /* MOV PC or MOVS PC. */
- nextpc = get_frame_register_unsigned (frame, bits (inst2, 0, 3));
- nextpc = MAKE_THUMB_ADDR (nextpc);
- }
- else if ((inst1 & 0xff70) == 0xf850 && (inst2 & 0xf000) == 0xf000)
- {
- /* LDR PC. */
- CORE_ADDR base;
- int rn, load_pc = 1;
+ if (bit (offset, 25))
+ offset = offset | ~0x3ffffff;
- rn = bits (inst1, 0, 3);
- base = get_frame_register_unsigned (frame, rn);
- if (rn == 15)
- {
- base = (base + 4) & ~(CORE_ADDR) 0x3;
- if (bit (inst1, 7))
- base += bits (inst2, 0, 11);
- else
- base -= bits (inst2, 0, 11);
- }
- else if (bit (inst1, 7))
- base += bits (inst2, 0, 11);
- else if (bit (inst2, 11))
- {
- if (bit (inst2, 10))
- {
- if (bit (inst2, 9))
- base += bits (inst2, 0, 7);
- else
- base -= bits (inst2, 0, 7);
- }
- }
- else if ((inst2 & 0x0fc0) == 0x0000)
- {
- int shift = bits (inst2, 4, 5), rm = bits (inst2, 0, 3);
- base += get_frame_register_unsigned (frame, rm) << shift;
- }
- else
- /* Reserved. */
- load_pc = 0;
+ dsc->modinsn[0] = ARM_NOP;
- if (load_pc)
- nextpc = get_frame_memory_unsigned (frame, base, 4);
- }
- else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
- {
- /* TBB. */
- CORE_ADDR tbl_reg, table, offset, length;
+ install_b_bl_blx (gdbarch, regs, dsc, cond, exchange, link, offset);
+ return 0;
+}
- tbl_reg = bits (inst1, 0, 3);
- if (tbl_reg == 0x0f)
- table = pc + 4; /* Regcache copy of PC isn't right yet. */
- else
- table = get_frame_register_unsigned (frame, tbl_reg);
+static int
+thumb2_copy_b_bl_blx (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ int link = bit (insn2, 14);
+ int exchange = link && !bit (insn2, 12);
+ int cond = INST_AL;
+ long offset = 0;
+ int j1 = bit (insn2, 13);
+ int j2 = bit (insn2, 11);
+ int s = sbits (insn1, 10, 10);
+ int i1 = !(j1 ^ bit (insn1, 10));
+ int i2 = !(j2 ^ bit (insn1, 10));
- offset = get_frame_register_unsigned (frame, bits (inst2, 0, 3));
- length = 2 * get_frame_memory_unsigned (frame, table + offset, 1);
- nextpc = pc_val + length;
+ if (!link && !exchange) /* B */
+ {
+ offset = (bits (insn2, 0, 10) << 1);
+ if (bit (insn2, 12)) /* Encoding T4 */
+ {
+ offset |= (bits (insn1, 0, 9) << 12)
+ | (i2 << 22)
+ | (i1 << 23)
+ | (s << 24);
+ cond = INST_AL;
}
- else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf010)
+ else /* Encoding T3 */
{
- /* TBH. */
- CORE_ADDR tbl_reg, table, offset, length;
-
- tbl_reg = bits (inst1, 0, 3);
- if (tbl_reg == 0x0f)
- table = pc + 4; /* Regcache copy of PC isn't right yet. */
- else
- table = get_frame_register_unsigned (frame, tbl_reg);
-
- offset = 2 * get_frame_register_unsigned (frame, bits (inst2, 0, 3));
- length = 2 * get_frame_memory_unsigned (frame, table + offset, 2);
- nextpc = pc_val + length;
+ offset |= (bits (insn1, 0, 5) << 12)
+ | (j1 << 18)
+ | (j2 << 19)
+ | (s << 20);
+ cond = bits (insn1, 6, 9);
}
}
- else if ((inst1 & 0xff00) == 0x4700) /* bx REG, blx REG */
- {
- if (bits (inst1, 3, 6) == 0x0f)
- nextpc = pc_val;
- else
- nextpc = get_frame_register_unsigned (frame, bits (inst1, 3, 6));
- }
- else if ((inst1 & 0xff87) == 0x4687) /* mov pc, REG */
+ else
{
- if (bits (inst1, 3, 6) == 0x0f)
- nextpc = pc_val;
- else
- nextpc = get_frame_register_unsigned (frame, bits (inst1, 3, 6));
-
- nextpc = MAKE_THUMB_ADDR (nextpc);
+ offset = (bits (insn1, 0, 9) << 12);
+ offset |= ((i2 << 22) | (i1 << 23) | (s << 24));
+ offset |= exchange ?
+ (bits (insn2, 1, 10) << 2) : (bits (insn2, 0, 10) << 1);
}
- else if ((inst1 & 0xf500) == 0xb100)
- {
- /* CBNZ or CBZ. */
- int imm = (bit (inst1, 9) << 6) + (bits (inst1, 3, 7) << 1);
- ULONGEST reg = get_frame_register_unsigned (frame, bits (inst1, 0, 2));
- if (bit (inst1, 11) && reg != 0)
- nextpc = pc_val + imm;
- else if (!bit (inst1, 11) && reg == 0)
- nextpc = pc_val + imm;
- }
- return nextpc;
-}
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying %s insn "
+ "%.4x %.4x with offset %.8lx\n",
+ link ? (exchange) ? "blx" : "bl" : "b",
+ insn1, insn2, offset);
-/* Get the raw next address. PC is the current program counter, in
- FRAME. INSERT_BKPT should be TRUE if we want a breakpoint set on
- the alternative next instruction if there are two options.
+ dsc->modinsn[0] = THUMB_NOP;
- The value returned has the execution state of the next instruction
- encoded in it. Use IS_THUMB_ADDR () to see whether the instruction is
- in Thumb-State, and gdbarch_addr_bits_remove () to get the plain memory
- address. */
+ install_b_bl_blx (gdbarch, regs, dsc, cond, exchange, link, offset);
+ return 0;
+}
-static CORE_ADDR
-arm_get_next_pc_raw (struct frame_info *frame, CORE_ADDR pc, int insert_bkpt)
+/* Copy B Thumb instructions. */
+static int
+thumb_copy_b (struct gdbarch *gdbarch, unsigned short insn,
+ struct displaced_step_closure *dsc)
{
- struct gdbarch *gdbarch = get_frame_arch (frame);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- unsigned long pc_val;
- unsigned long this_instr;
- unsigned long status;
- CORE_ADDR nextpc;
+ unsigned int cond = 0;
+ int offset = 0;
+ unsigned short bit_12_15 = bits (insn, 12, 15);
+ CORE_ADDR from = dsc->insn_addr;
- if (arm_frame_is_thumb (frame))
- return thumb_get_next_pc_raw (frame, pc, insert_bkpt);
+ if (bit_12_15 == 0xd)
+ {
+ /* offset = SignExtend (imm8:0, 32) */
+ offset = sbits ((insn << 1), 0, 8);
+ cond = bits (insn, 8, 11);
+ }
+ else if (bit_12_15 == 0xe) /* Encoding T2 */
+ {
+ offset = sbits ((insn << 1), 0, 11);
+ cond = INST_AL;
+ }
- pc_val = (unsigned long) pc;
- this_instr = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying b immediate insn %.4x "
+ "with offset %d\n", insn, offset);
- status = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
- nextpc = (CORE_ADDR) (pc_val + 4); /* Default case */
+ dsc->u.branch.cond = cond;
+ dsc->u.branch.link = 0;
+ dsc->u.branch.exchange = 0;
+ dsc->u.branch.dest = from + 4 + offset;
- if (bits (this_instr, 28, 31) == INST_NV)
- switch (bits (this_instr, 24, 27))
- {
- case 0xa:
- case 0xb:
- {
- /* Branch with Link and change to Thumb. */
- nextpc = BranchDest (pc, this_instr);
- nextpc |= bit (this_instr, 24) << 1;
- nextpc = MAKE_THUMB_ADDR (nextpc);
- break;
- }
- case 0xc:
- case 0xd:
- case 0xe:
- /* Coprocessor register transfer. */
- if (bits (this_instr, 12, 15) == 15)
- error (_("Invalid update to pc in instruction"));
- break;
- }
- else if (condition_true (bits (this_instr, 28, 31), status))
- {
- switch (bits (this_instr, 24, 27))
- {
- case 0x0:
- case 0x1: /* data processing */
- case 0x2:
- case 0x3:
- {
- unsigned long operand1, operand2, result = 0;
- unsigned long rn;
- int c;
+ dsc->modinsn[0] = THUMB_NOP;
- if (bits (this_instr, 12, 15) != 15)
- break;
+ dsc->cleanup = &cleanup_branch;
- if (bits (this_instr, 22, 25) == 0
- && bits (this_instr, 4, 7) == 9) /* multiply */
- error (_("Invalid update to pc in instruction"));
+ return 0;
+}
- /* BX <reg>, BLX <reg> */
- if (bits (this_instr, 4, 27) == 0x12fff1
- || bits (this_instr, 4, 27) == 0x12fff3)
- {
- rn = bits (this_instr, 0, 3);
- nextpc = (rn == 15) ? pc_val + 8
- : get_frame_register_unsigned (frame, rn);
- return nextpc;
- }
+/* Copy BX/BLX with register-specified destinations. */
- /* Multiply into PC. */
- c = (status & FLAG_C) ? 1 : 0;
- rn = bits (this_instr, 16, 19);
- operand1 = (rn == 15) ? pc_val + 8
- : get_frame_register_unsigned (frame, rn);
+static void
+install_bx_blx_reg (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc, int link,
+ unsigned int cond, unsigned int rm)
+{
+ /* Implement {BX,BLX}<cond> <reg>" as:
- if (bit (this_instr, 25))
- {
- unsigned long immval = bits (this_instr, 0, 7);
- unsigned long rotate = 2 * bits (this_instr, 8, 11);
- operand2 = ((immval >> rotate) | (immval << (32 - rotate)))
- & 0xffffffff;
- }
- else /* operand 2 is a shifted register. */
- operand2 = shifted_reg_val (frame, this_instr, c,
- pc_val, status);
+ Preparation: cond <- instruction condition
+ Insn: mov r0, r0 (nop)
+ Cleanup: if (condition true) { r14 <- pc; pc <- dest; }.
- switch (bits (this_instr, 21, 24))
- {
- case 0x0: /*and */
- result = operand1 & operand2;
- break;
+ Don't set r14 in cleanup for BX. */
- case 0x1: /*eor */
- result = operand1 ^ operand2;
- break;
+ dsc->u.branch.dest = displaced_read_reg (regs, dsc, rm);
- case 0x2: /*sub */
- result = operand1 - operand2;
- break;
+ dsc->u.branch.cond = cond;
+ dsc->u.branch.link = link;
- case 0x3: /*rsb */
- result = operand2 - operand1;
- break;
+ dsc->u.branch.exchange = 1;
- case 0x4: /*add */
- result = operand1 + operand2;
- break;
+ dsc->cleanup = &cleanup_branch;
+}
- case 0x5: /*adc */
- result = operand1 + operand2 + c;
- break;
+static int
+arm_copy_bx_blx_reg (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int cond = bits (insn, 28, 31);
+ /* BX: x12xxx1x
+ BLX: x12xxx3x. */
+ int link = bit (insn, 5);
+ unsigned int rm = bits (insn, 0, 3);
- case 0x6: /*sbc */
- result = operand1 - operand2 + c;
- break;
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying insn %.8lx",
+ (unsigned long) insn);
- case 0x7: /*rsc */
- result = operand2 - operand1 + c;
- break;
+ dsc->modinsn[0] = ARM_NOP;
- case 0x8:
- case 0x9:
- case 0xa:
- case 0xb: /* tst, teq, cmp, cmn */
- result = (unsigned long) nextpc;
- break;
+ install_bx_blx_reg (gdbarch, regs, dsc, link, cond, rm);
+ return 0;
+}
- case 0xc: /*orr */
- result = operand1 | operand2;
- break;
+static int
+thumb_copy_bx_blx_reg (struct gdbarch *gdbarch, uint16_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ int link = bit (insn, 7);
+ unsigned int rm = bits (insn, 3, 6);
- case 0xd: /*mov */
- /* Always step into a function. */
- result = operand2;
- break;
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying insn %.4x",
+ (unsigned short) insn);
- case 0xe: /*bic */
- result = operand1 & ~operand2;
- break;
+ dsc->modinsn[0] = THUMB_NOP;
- case 0xf: /*mvn */
- result = ~operand2;
- break;
- }
+ install_bx_blx_reg (gdbarch, regs, dsc, link, INST_AL, rm);
- /* In 26-bit APCS the bottom two bits of the result are
- ignored, and we always end up in ARM state. */
- if (!arm_apcs_32)
- nextpc = arm_addr_bits_remove (gdbarch, result);
- else
- nextpc = result;
+ return 0;
+}
- break;
- }
- case 0x4:
- case 0x5: /* data transfer */
- case 0x6:
- case 0x7:
- if (bit (this_instr, 20))
- {
- /* load */
- if (bits (this_instr, 12, 15) == 15)
- {
- /* rd == pc */
- unsigned long rn;
- unsigned long base;
+/* Copy/cleanup arithmetic/logic instruction with immediate RHS. */
- if (bit (this_instr, 22))
- error (_("Invalid update to pc in instruction"));
+static void
+cleanup_alu_imm (struct gdbarch *gdbarch,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ ULONGEST rd_val = displaced_read_reg (regs, dsc, 0);
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
+}
- /* byte write to PC */
- rn = bits (this_instr, 16, 19);
- base = (rn == 15) ? pc_val + 8
- : get_frame_register_unsigned (frame, rn);
- if (bit (this_instr, 24))
- {
- /* pre-indexed */
- int c = (status & FLAG_C) ? 1 : 0;
- unsigned long offset =
- (bit (this_instr, 25)
- ? shifted_reg_val (frame, this_instr, c, pc_val, status)
- : bits (this_instr, 0, 11));
+static int
+arm_copy_alu_imm (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rn = bits (insn, 16, 19);
+ unsigned int rd = bits (insn, 12, 15);
+ unsigned int op = bits (insn, 21, 24);
+ int is_mov = (op == 0xd);
+ ULONGEST rd_val, rn_val;
- if (bit (this_instr, 23))
- base += offset;
- else
- base -= offset;
- }
- nextpc = (CORE_ADDR) read_memory_integer ((CORE_ADDR) base,
- 4, byte_order);
- }
- }
- break;
+ if (!insn_references_pc (insn, 0x000ff000ul))
+ return arm_copy_unmodified (gdbarch, insn, "ALU immediate", dsc);
- case 0x8:
- case 0x9: /* block transfer */
- if (bit (this_instr, 20))
- {
- /* LDM */
- if (bit (this_instr, 15))
- {
- /* loading pc */
- int offset = 0;
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying immediate %s insn "
+ "%.8lx\n", is_mov ? "move" : "ALU",
+ (unsigned long) insn);
- if (bit (this_instr, 23))
- {
- /* up */
- unsigned long reglist = bits (this_instr, 0, 14);
- offset = bitcount (reglist) * 4;
- if (bit (this_instr, 24)) /* pre */
- offset += 4;
- }
- else if (bit (this_instr, 24))
- offset = -4;
+ /* Instruction is of form:
- {
- unsigned long rn_val =
- get_frame_register_unsigned (frame,
- bits (this_instr, 16, 19));
- nextpc =
- (CORE_ADDR) read_memory_integer ((CORE_ADDR) (rn_val
- + offset),
- 4, byte_order);
- }
- }
- }
- break;
+ <op><cond> rd, [rn,] #imm
- case 0xb: /* branch & link */
- case 0xa: /* branch */
- {
- nextpc = BranchDest (pc, this_instr);
- break;
- }
+ Rewrite as:
- case 0xc:
- case 0xd:
- case 0xe: /* coproc ops */
- break;
- case 0xf: /* SWI */
- {
- struct gdbarch_tdep *tdep;
- tdep = gdbarch_tdep (gdbarch);
+ Preparation: tmp1, tmp2 <- r0, r1;
+ r0, r1 <- rd, rn
+ Insn: <op><cond> r0, r1, #imm
+ Cleanup: rd <- r0; r0 <- tmp1; r1 <- tmp2
+ */
- if (tdep->syscall_next_pc != NULL)
- nextpc = tdep->syscall_next_pc (frame);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ rd_val = displaced_read_reg (regs, dsc, rd);
+ displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
+ dsc->rd = rd;
- }
- break;
+ if (is_mov)
+ dsc->modinsn[0] = insn & 0xfff00fff;
+ else
+ dsc->modinsn[0] = (insn & 0xfff00fff) | 0x10000;
- default:
- fprintf_filtered (gdb_stderr, _("Bad bit-field extraction\n"));
- return (pc);
- }
- }
+ dsc->cleanup = &cleanup_alu_imm;
- return nextpc;
+ return 0;
}
-CORE_ADDR
-arm_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
+static int
+thumb2_copy_alu_imm (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- struct gdbarch *gdbarch = get_frame_arch (frame);
- CORE_ADDR nextpc =
- gdbarch_addr_bits_remove (gdbarch,
- arm_get_next_pc_raw (frame, pc, TRUE));
- if (nextpc == pc)
- error (_("Infinite loop detected"));
- return nextpc;
-}
+ unsigned int op = bits (insn1, 5, 8);
+ unsigned int rn, rm, rd;
+ ULONGEST rd_val, rn_val;
-/* single_step() is called just before we want to resume the inferior,
- if we want to single-step it but there is no hardware or kernel
- single-step support. We find the target of the coming instruction
- and breakpoint it. */
+ rn = bits (insn1, 0, 3); /* Rn */
+ rm = bits (insn2, 0, 3); /* Rm */
+ rd = bits (insn2, 8, 11); /* Rd */
-int
-arm_software_single_step (struct frame_info *frame)
-{
- struct gdbarch *gdbarch = get_frame_arch (frame);
- struct address_space *aspace = get_frame_address_space (frame);
+ /* This routine is only called for instruction MOV. */
+ gdb_assert (op == 0x2 && rn == 0xf);
- /* NOTE: This may insert the wrong breakpoint instruction when
- single-stepping over a mode-changing instruction, if the
- CPSR heuristics are used. */
+ if (rm != ARM_PC_REGNUM && rd != ARM_PC_REGNUM)
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "ALU imm", dsc);
- CORE_ADDR next_pc = arm_get_next_pc (frame, get_frame_pc (frame));
- insert_single_step_breakpoint (gdbarch, aspace, next_pc);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying reg %s insn %.4x%.4x\n",
+ "ALU", insn1, insn2);
- return 1;
+ /* Instruction is of form:
+
+ <op><cond> rd, [rn,] #imm
+
+ Rewrite as:
+
+ Preparation: tmp1, tmp2 <- r0, r1;
+ r0, r1 <- rd, rn
+ Insn: <op><cond> r0, r1, #imm
+ Cleanup: rd <- r0; r0 <- tmp1; r1 <- tmp2
+ */
+
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ rd_val = displaced_read_reg (regs, dsc, rd);
+ displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
+ dsc->rd = rd;
+
+ dsc->modinsn[0] = insn1;
+ dsc->modinsn[1] = ((insn2 & 0xf0f0) | 0x1);
+ dsc->numinsns = 2;
+
+ dsc->cleanup = &cleanup_alu_imm;
+
+ return 0;
}
-/* Given BUF, which is OLD_LEN bytes ending at ENDADDR, expand
- the buffer to be NEW_LEN bytes ending at ENDADDR. Return
- NULL if an error occurs. BUF is freed. */
+/* Copy/cleanup arithmetic/logic insns with register RHS. */
-static gdb_byte *
-extend_buffer_earlier (gdb_byte *buf, CORE_ADDR endaddr,
- int old_len, int new_len)
+static void
+cleanup_alu_reg (struct gdbarch *gdbarch,
+ struct regcache *regs, struct displaced_step_closure *dsc)
{
- gdb_byte *new_buf, *middle;
- int bytes_to_read = new_len - old_len;
+ ULONGEST rd_val;
+ int i;
- new_buf = xmalloc (new_len);
- memcpy (new_buf + bytes_to_read, buf, old_len);
- xfree (buf);
- if (target_read_memory (endaddr - new_len, new_buf, bytes_to_read) != 0)
- {
- xfree (new_buf);
- return NULL;
- }
- return new_buf;
-}
+ rd_val = displaced_read_reg (regs, dsc, 0);
-/* An IT block is at most the 2-byte IT instruction followed by
- four 4-byte instructions. The furthest back we must search to
- find an IT block that affects the current instruction is thus
- 2 + 3 * 4 == 14 bytes. */
-#define MAX_IT_BLOCK_PREFIX 14
+ for (i = 0; i < 3; i++)
+ displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC);
-/* Use a quick scan if there are more than this many bytes of
- code. */
-#define IT_SCAN_THRESHOLD 32
+ displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
+}
-/* Adjust a breakpoint's address to move breakpoints out of IT blocks.
- A breakpoint in an IT block may not be hit, depending on the
- condition flags. */
-static CORE_ADDR
-arm_adjust_breakpoint_address (struct gdbarch *gdbarch, CORE_ADDR bpaddr)
+static void
+install_alu_reg (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc,
+ unsigned int rd, unsigned int rn, unsigned int rm)
{
- gdb_byte *buf;
- char map_type;
- CORE_ADDR boundary, func_start;
- int buf_len, buf2_len;
- enum bfd_endian order = gdbarch_byte_order_for_code (gdbarch);
- int i, any, last_it, last_it_count;
-
- /* If we are using BKPT breakpoints, none of this is necessary. */
- if (gdbarch_tdep (gdbarch)->thumb2_breakpoint == NULL)
- return bpaddr;
+ ULONGEST rd_val, rn_val, rm_val;
- /* ARM mode does not have this problem. */
- if (!arm_pc_is_thumb (gdbarch, bpaddr))
- return bpaddr;
+ /* Instruction is of form:
- /* We are setting a breakpoint in Thumb code that could potentially
- contain an IT block. The first step is to find how much Thumb
- code there is; we do not need to read outside of known Thumb
- sequences. */
- map_type = arm_find_mapping_symbol (bpaddr, &boundary);
- if (map_type == 0)
- /* Thumb-2 code must have mapping symbols to have a chance. */
- return bpaddr;
+ <op><cond> rd, [rn,] rm [, <shift>]
- bpaddr = gdbarch_addr_bits_remove (gdbarch, bpaddr);
+ Rewrite as:
- if (find_pc_partial_function (bpaddr, NULL, &func_start, NULL)
- && func_start > boundary)
- boundary = func_start;
+ Preparation: tmp1, tmp2, tmp3 <- r0, r1, r2;
+ r0, r1, r2 <- rd, rn, rm
+ Insn: <op><cond> r0, r1, r2 [, <shift>]
+ Cleanup: rd <- r0; r0, r1, r2 <- tmp1, tmp2, tmp3
+ */
- /* Search for a candidate IT instruction. We have to do some fancy
- footwork to distinguish a real IT instruction from the second
- half of a 32-bit instruction, but there is no need for that if
- there's no candidate. */
- buf_len = min (bpaddr - boundary, MAX_IT_BLOCK_PREFIX);
- if (buf_len == 0)
- /* No room for an IT instruction. */
- return bpaddr;
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
+ dsc->tmp[2] = displaced_read_reg (regs, dsc, 2);
+ rd_val = displaced_read_reg (regs, dsc, rd);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ rm_val = displaced_read_reg (regs, dsc, rm);
+ displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
+ dsc->rd = rd;
- buf = xmalloc (buf_len);
- if (target_read_memory (bpaddr - buf_len, buf, buf_len) != 0)
- return bpaddr;
- any = 0;
- for (i = 0; i < buf_len; i += 2)
- {
- unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
- if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
- {
- any = 1;
- break;
- }
- }
- if (any == 0)
- {
- xfree (buf);
- return bpaddr;
- }
+ dsc->cleanup = &cleanup_alu_reg;
+}
- /* OK, the code bytes before this instruction contain at least one
- halfword which resembles an IT instruction. We know that it's
- Thumb code, but there are still two possibilities. Either the
- halfword really is an IT instruction, or it is the second half of
- a 32-bit Thumb instruction. The only way we can tell is to
- scan forwards from a known instruction boundary. */
- if (bpaddr - boundary > IT_SCAN_THRESHOLD)
- {
- int definite;
+static int
+arm_copy_alu_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int op = bits (insn, 21, 24);
+ int is_mov = (op == 0xd);
- /* There's a lot of code before this instruction. Start with an
- optimistic search; it's easy to recognize halfwords that can
- not be the start of a 32-bit instruction, and use that to
- lock on to the instruction boundaries. */
- buf = extend_buffer_earlier (buf, bpaddr, buf_len, IT_SCAN_THRESHOLD);
- if (buf == NULL)
- return bpaddr;
- buf_len = IT_SCAN_THRESHOLD;
+ if (!insn_references_pc (insn, 0x000ff00ful))
+ return arm_copy_unmodified (gdbarch, insn, "ALU reg", dsc);
- definite = 0;
- for (i = 0; i < buf_len - sizeof (buf) && ! definite; i += 2)
- {
- unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
- if (thumb_insn_size (inst1) == 2)
- {
- definite = 1;
- break;
- }
- }
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying reg %s insn %.8lx\n",
+ is_mov ? "move" : "ALU", (unsigned long) insn);
- /* At this point, if DEFINITE, BUF[I] is the first place we
- are sure that we know the instruction boundaries, and it is far
- enough from BPADDR that we could not miss an IT instruction
- affecting BPADDR. If ! DEFINITE, give up - start from a
- known boundary. */
- if (! definite)
- {
- buf = extend_buffer_earlier (buf, bpaddr, buf_len,
- bpaddr - boundary);
- if (buf == NULL)
- return bpaddr;
- buf_len = bpaddr - boundary;
- i = 0;
- }
- }
+ if (is_mov)
+ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x2;
else
- {
- buf = extend_buffer_earlier (buf, bpaddr, buf_len, bpaddr - boundary);
- if (buf == NULL)
- return bpaddr;
- buf_len = bpaddr - boundary;
- i = 0;
- }
+ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x10002;
- /* Scan forwards. Find the last IT instruction before BPADDR. */
- last_it = -1;
- last_it_count = 0;
- while (i < buf_len)
- {
- unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
- last_it_count--;
- if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
- {
- last_it = i;
- if (inst1 & 0x0001)
- last_it_count = 4;
- else if (inst1 & 0x0002)
- last_it_count = 3;
- else if (inst1 & 0x0004)
- last_it_count = 2;
- else
- last_it_count = 1;
- }
- i += thumb_insn_size (inst1);
- }
+ install_alu_reg (gdbarch, regs, dsc, bits (insn, 12, 15), bits (insn, 16, 19),
+ bits (insn, 0, 3));
+ return 0;
+}
- xfree (buf);
+static int
+thumb_copy_alu_reg (struct gdbarch *gdbarch, uint16_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned rn, rm, rd;
- if (last_it == -1)
- /* There wasn't really an IT instruction after all. */
- return bpaddr;
+ rd = bits (insn, 3, 6);
+ rn = (bit (insn, 7) << 3) | bits (insn, 0, 2);
+ rm = 2;
+
+ if (rd != ARM_PC_REGNUM && rn != ARM_PC_REGNUM)
+ return thumb_copy_unmodified_16bit (gdbarch, insn, "ALU reg", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying reg %s insn %.4x\n",
+ "ALU", (unsigned short) insn);
- if (last_it_count < 1)
- /* It was too far away. */
- return bpaddr;
+ dsc->modinsn[0] = ((insn & 0xff00) | 0x08);
- /* This really is a trouble spot. Move the breakpoint to the IT
- instruction. */
- return bpaddr - buf_len + last_it;
+ install_alu_reg (gdbarch, regs, dsc, rd, rn, rm);
+
+ return 0;
}
-/* ARM displaced stepping support.
+/* Cleanup/copy arithmetic/logic insns with shifted register RHS. */
- Generally ARM displaced stepping works as follows:
+static void
+cleanup_alu_shifted_reg (struct gdbarch *gdbarch,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ ULONGEST rd_val = displaced_read_reg (regs, dsc, 0);
+ int i;
- 1. When an instruction is to be single-stepped, it is first decoded by
- arm_process_displaced_insn (called from arm_displaced_step_copy_insn).
- Depending on the type of instruction, it is then copied to a scratch
- location, possibly in a modified form. The copy_* set of functions
- performs such modification, as necessary. A breakpoint is placed after
- the modified instruction in the scratch space to return control to GDB.
- Note in particular that instructions which modify the PC will no longer
- do so after modification.
+ for (i = 0; i < 4; i++)
+ displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC);
- 2. The instruction is single-stepped, by setting the PC to the scratch
- location address, and resuming. Control returns to GDB when the
- breakpoint is hit.
+ displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
+}
- 3. A cleanup function (cleanup_*) is called corresponding to the copy_*
- function used for the current instruction. This function's job is to
- put the CPU/memory state back to what it would have been if the
- instruction had been executed unmodified in its original location. */
+static void
+install_alu_shifted_reg (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc,
+ unsigned int rd, unsigned int rn, unsigned int rm,
+ unsigned rs)
+{
+ int i;
+ ULONGEST rd_val, rn_val, rm_val, rs_val;
-/* NOP instruction (mov r0, r0). */
-#define ARM_NOP 0xe1a00000
+ /* Instruction is of form:
-/* Helper for register reads for displaced stepping. In particular, this
- returns the PC as it would be seen by the instruction at its original
- location. */
+ <op><cond> rd, [rn,] rm, <shift> rs
-ULONGEST
-displaced_read_reg (struct regcache *regs, CORE_ADDR from, int regno)
-{
- ULONGEST ret;
+ Rewrite as:
- if (regno == 15)
- {
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: read pc value %.8lx\n",
- (unsigned long) from + 8);
- return (ULONGEST) from + 8; /* Pipeline offset. */
- }
- else
- {
- regcache_cooked_read_unsigned (regs, regno, &ret);
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: read r%d value %.8lx\n",
- regno, (unsigned long) ret);
- return ret;
- }
+ Preparation: tmp1, tmp2, tmp3, tmp4 <- r0, r1, r2, r3
+ r0, r1, r2, r3 <- rd, rn, rm, rs
+ Insn: <op><cond> r0, r1, r2, <shift> r3
+ Cleanup: tmp5 <- r0
+ r0, r1, r2, r3 <- tmp1, tmp2, tmp3, tmp4
+ rd <- tmp5
+ */
+
+ for (i = 0; i < 4; i++)
+ dsc->tmp[i] = displaced_read_reg (regs, dsc, i);
+
+ rd_val = displaced_read_reg (regs, dsc, rd);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ rm_val = displaced_read_reg (regs, dsc, rm);
+ rs_val = displaced_read_reg (regs, dsc, rs);
+ displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 3, rs_val, CANNOT_WRITE_PC);
+ dsc->rd = rd;
+ dsc->cleanup = &cleanup_alu_shifted_reg;
}
static int
-displaced_in_arm_mode (struct regcache *regs)
+arm_copy_alu_shifted_reg (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- ULONGEST ps;
- ULONGEST t_bit = arm_psr_thumb_bit (get_regcache_arch (regs));
+ unsigned int op = bits (insn, 21, 24);
+ int is_mov = (op == 0xd);
+ unsigned int rd, rn, rm, rs;
- regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
+ if (!insn_references_pc (insn, 0x000fff0ful))
+ return arm_copy_unmodified (gdbarch, insn, "ALU shifted reg", dsc);
- return (ps & t_bit) == 0;
-}
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying shifted reg %s insn "
+ "%.8lx\n", is_mov ? "move" : "ALU",
+ (unsigned long) insn);
-/* Write to the PC as from a branch instruction. */
+ rn = bits (insn, 16, 19);
+ rm = bits (insn, 0, 3);
+ rs = bits (insn, 8, 11);
+ rd = bits (insn, 12, 15);
-static void
-branch_write_pc (struct regcache *regs, ULONGEST val)
-{
- if (displaced_in_arm_mode (regs))
- /* Note: If bits 0/1 are set, this branch would be unpredictable for
- architecture versions < 6. */
- regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM,
- val & ~(ULONGEST) 0x3);
+ if (is_mov)
+ dsc->modinsn[0] = (insn & 0xfff000f0) | 0x302;
else
- regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM,
- val & ~(ULONGEST) 0x1);
+ dsc->modinsn[0] = (insn & 0xfff000f0) | 0x10302;
+
+ install_alu_shifted_reg (gdbarch, regs, dsc, rd, rn, rm, rs);
+
+ return 0;
}
-/* Write to the PC as from a branch-exchange instruction. */
+/* Clean up load instructions. */
static void
-bx_write_pc (struct regcache *regs, ULONGEST val)
+cleanup_load (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- ULONGEST ps;
- ULONGEST t_bit = arm_psr_thumb_bit (get_regcache_arch (regs));
+ ULONGEST rt_val, rt_val2 = 0, rn_val;
- regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
+ rt_val = displaced_read_reg (regs, dsc, 0);
+ if (dsc->u.ldst.xfersize == 8)
+ rt_val2 = displaced_read_reg (regs, dsc, 1);
+ rn_val = displaced_read_reg (regs, dsc, 2);
- if ((val & 1) == 1)
- {
- regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps | t_bit);
- regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffe);
- }
- else if ((val & 2) == 0)
- {
- regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit);
- regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val);
- }
- else
- {
- /* Unpredictable behaviour. Try to do something sensible (switch to ARM
- mode, align dest to 4 bytes). */
- warning (_("Single-stepping BX to non-word-aligned ARM instruction."));
- regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit);
- regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffc);
- }
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
+ if (dsc->u.ldst.xfersize > 4)
+ displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC);
+ if (!dsc->u.ldst.immed)
+ displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC);
+
+ /* Handle register writeback. */
+ if (dsc->u.ldst.writeback)
+ displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC);
+ /* Put result in right place. */
+ displaced_write_reg (regs, dsc, dsc->rd, rt_val, LOAD_WRITE_PC);
+ if (dsc->u.ldst.xfersize == 8)
+ displaced_write_reg (regs, dsc, dsc->rd + 1, rt_val2, LOAD_WRITE_PC);
}
-/* Write to the PC as if from a load instruction. */
+/* Clean up store instructions. */
static void
-load_write_pc (struct regcache *regs, ULONGEST val)
+cleanup_store (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- if (DISPLACED_STEPPING_ARCH_VERSION >= 5)
- bx_write_pc (regs, val);
- else
- branch_write_pc (regs, val);
-}
+ ULONGEST rn_val = displaced_read_reg (regs, dsc, 2);
-/* Write to the PC as if from an ALU instruction. */
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
+ if (dsc->u.ldst.xfersize > 4)
+ displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC);
+ if (!dsc->u.ldst.immed)
+ displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC);
+ if (!dsc->u.ldst.restore_r4)
+ displaced_write_reg (regs, dsc, 4, dsc->tmp[4], CANNOT_WRITE_PC);
-static void
-alu_write_pc (struct regcache *regs, ULONGEST val)
-{
- if (DISPLACED_STEPPING_ARCH_VERSION >= 7 && displaced_in_arm_mode (regs))
- bx_write_pc (regs, val);
- else
- branch_write_pc (regs, val);
+ /* Writeback. */
+ if (dsc->u.ldst.writeback)
+ displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC);
}
-/* Helper for writing to registers for displaced stepping. Writing to the PC
- has a varying effects depending on the instruction which does the write:
- this is controlled by the WRITE_PC argument. */
+/* Copy "extra" load/store instructions. These are halfword/doubleword
+ transfers, which have a different encoding to byte/word transfers. */
-void
-displaced_write_reg (struct regcache *regs, struct displaced_step_closure *dsc,
- int regno, ULONGEST val, enum pc_write_style write_pc)
+static int
+arm_copy_extra_ld_st (struct gdbarch *gdbarch, uint32_t insn, int unpriveleged,
+ struct regcache *regs, struct displaced_step_closure *dsc)
{
- if (regno == 15)
- {
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: writing pc %.8lx\n",
- (unsigned long) val);
- switch (write_pc)
- {
- case BRANCH_WRITE_PC:
- branch_write_pc (regs, val);
- break;
+ unsigned int op1 = bits (insn, 20, 24);
+ unsigned int op2 = bits (insn, 5, 6);
+ unsigned int rt = bits (insn, 12, 15);
+ unsigned int rn = bits (insn, 16, 19);
+ unsigned int rm = bits (insn, 0, 3);
+ char load[12] = {0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1};
+ char bytesize[12] = {2, 2, 2, 2, 8, 1, 8, 1, 8, 2, 8, 2};
+ int immed = (op1 & 0x4) != 0;
+ int opcode;
+ ULONGEST rt_val, rt_val2 = 0, rn_val, rm_val = 0;
- case BX_WRITE_PC:
- bx_write_pc (regs, val);
- break;
+ if (!insn_references_pc (insn, 0x000ff00ful))
+ return arm_copy_unmodified (gdbarch, insn, "extra load/store", dsc);
- case LOAD_WRITE_PC:
- load_write_pc (regs, val);
- break;
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying %sextra load/store "
+ "insn %.8lx\n", unpriveleged ? "unpriveleged " : "",
+ (unsigned long) insn);
- case ALU_WRITE_PC:
- alu_write_pc (regs, val);
- break;
+ opcode = ((op2 << 2) | (op1 & 0x1) | ((op1 & 0x4) >> 1)) - 4;
- case CANNOT_WRITE_PC:
- warning (_("Instruction wrote to PC in an unexpected way when "
- "single-stepping"));
- break;
+ if (opcode < 0)
+ internal_error (__FILE__, __LINE__,
+ _("copy_extra_ld_st: instruction decode error"));
- default:
- internal_error (__FILE__, __LINE__,
- _("Invalid argument to displaced_write_reg"));
- }
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, dsc, 1);
+ dsc->tmp[2] = displaced_read_reg (regs, dsc, 2);
+ if (!immed)
+ dsc->tmp[3] = displaced_read_reg (regs, dsc, 3);
+
+ rt_val = displaced_read_reg (regs, dsc, rt);
+ if (bytesize[opcode] == 8)
+ rt_val2 = displaced_read_reg (regs, dsc, rt + 1);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ if (!immed)
+ rm_val = displaced_read_reg (regs, dsc, rm);
+
+ displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
+ if (bytesize[opcode] == 8)
+ displaced_write_reg (regs, dsc, 1, rt_val2, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC);
+ if (!immed)
+ displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC);
+
+ dsc->rd = rt;
+ dsc->u.ldst.xfersize = bytesize[opcode];
+ dsc->u.ldst.rn = rn;
+ dsc->u.ldst.immed = immed;
+ dsc->u.ldst.writeback = bit (insn, 24) == 0 || bit (insn, 21) != 0;
+ dsc->u.ldst.restore_r4 = 0;
+
+ if (immed)
+ /* {ldr,str}<width><cond> rt, [rt2,] [rn, #imm]
+ ->
+ {ldr,str}<width><cond> r0, [r1,] [r2, #imm]. */
+ dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000;
+ else
+ /* {ldr,str}<width><cond> rt, [rt2,] [rn, +/-rm]
+ ->
+ {ldr,str}<width><cond> r0, [r1,] [r2, +/-r3]. */
+ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003;
+
+ dsc->cleanup = load[opcode] ? &cleanup_load : &cleanup_store;
- dsc->wrote_to_pc = 1;
- }
- else
- {
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: writing r%d value %.8lx\n",
- regno, (unsigned long) val);
- regcache_cooked_write_unsigned (regs, regno, val);
- }
+ return 0;
}
-/* This function is used to concisely determine if an instruction INSN
- references PC. Register fields of interest in INSN should have the
- corresponding fields of BITMASK set to 0b1111. The function
- returns return 1 if any of these fields in INSN reference the PC
- (also 0b1111, r15), else it returns 0. */
+/* Copy byte/half word/word loads and stores. */
-static int
-insn_references_pc (uint32_t insn, uint32_t bitmask)
+static void
+install_load_store (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc, int load,
+ int immed, int writeback, int size, int usermode,
+ int rt, int rm, int rn)
{
- uint32_t lowbit = 1;
+ ULONGEST rt_val, rn_val, rm_val = 0;
- while (bitmask != 0)
- {
- uint32_t mask;
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[2] = displaced_read_reg (regs, dsc, 2);
+ if (!immed)
+ dsc->tmp[3] = displaced_read_reg (regs, dsc, 3);
+ if (!load)
+ dsc->tmp[4] = displaced_read_reg (regs, dsc, 4);
- for (; lowbit && (bitmask & lowbit) == 0; lowbit <<= 1)
- ;
+ rt_val = displaced_read_reg (regs, dsc, rt);
+ rn_val = displaced_read_reg (regs, dsc, rn);
+ if (!immed)
+ rm_val = displaced_read_reg (regs, dsc, rm);
- if (!lowbit)
- break;
+ displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC);
+ if (!immed)
+ displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC);
+ dsc->rd = rt;
+ dsc->u.ldst.xfersize = size;
+ dsc->u.ldst.rn = rn;
+ dsc->u.ldst.immed = immed;
+ dsc->u.ldst.writeback = writeback;
- mask = lowbit * 0xf;
+ /* To write PC we can do:
- if ((insn & mask) == mask)
- return 1;
+ Before this sequence of instructions:
+ r0 is the PC value got from displaced_read_reg, so r0 = from + 8;
+ r2 is the Rn value got from dispalced_read_reg.
- bitmask &= ~mask;
- }
+ Insn1: push {pc} Write address of STR instruction + offset on stack
+ Insn2: pop {r4} Read it back from stack, r4 = addr(Insn1) + offset
+ Insn3: sub r4, r4, pc r4 = addr(Insn1) + offset - pc
+ = addr(Insn1) + offset - addr(Insn3) - 8
+ = offset - 16
+ Insn4: add r4, r4, #8 r4 = offset - 8
+ Insn5: add r0, r0, r4 r0 = from + 8 + offset - 8
+ = from + offset
+ Insn6: str r0, [r2, #imm] (or str r0, [r2, r3])
- return 0;
+ Otherwise we don't know what value to write for PC, since the offset is
+ architecture-dependent (sometimes PC+8, sometimes PC+12). More details
+ of this can be found in Section "Saving from r15" in
+ http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0204g/Cihbjifh.html */
+
+ dsc->cleanup = load ? &cleanup_load : &cleanup_store;
}
-/* The simplest copy function. Many instructions have the same effect no
- matter what address they are executed at: in those cases, use this. */
static int
-copy_unmodified (struct gdbarch *gdbarch, uint32_t insn,
- const char *iname, struct displaced_step_closure *dsc)
+thumb2_copy_load_literal (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc, int size)
{
+ unsigned int u_bit = bit (insn1, 7);
+ unsigned int rt = bits (insn2, 12, 15);
+ int imm12 = bits (insn2, 0, 11);
+ ULONGEST pc_val;
+
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying insn %.8lx, "
- "opcode/class '%s' unmodified\n", (unsigned long) insn,
- iname);
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying ldr pc (0x%x) R%d %c imm12 %.4x\n",
+ (unsigned int) dsc->insn_addr, rt, u_bit ? '+' : '-',
+ imm12);
- dsc->modinsn[0] = insn;
+ if (!u_bit)
+ imm12 = -1 * imm12;
- return 0;
-}
+ /* Rewrite instruction LDR Rt imm12 into:
-/* Preload instructions with immediate offset. */
+ Prepare: tmp[0] <- r0, tmp[1] <- r2, tmp[2] <- r3, r2 <- pc, r3 <- imm12
-static void
-cleanup_preload (struct gdbarch *gdbarch,
- struct regcache *regs, struct displaced_step_closure *dsc)
-{
- displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
- if (!dsc->u.preload.immed)
- displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
-}
+ LDR R0, R2, R3,
-static int
-copy_preload (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
- struct displaced_step_closure *dsc)
-{
- unsigned int rn = bits (insn, 16, 19);
- ULONGEST rn_val;
- CORE_ADDR from = dsc->insn_addr;
+ Cleanup: rt <- r0, r0 <- tmp[0], r2 <- tmp[1], r3 <- tmp[2]. */
- if (!insn_references_pc (insn, 0x000f0000ul))
- return copy_unmodified (gdbarch, insn, "preload", dsc);
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying preload insn %.8lx\n",
- (unsigned long) insn);
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[2] = displaced_read_reg (regs, dsc, 2);
+ dsc->tmp[3] = displaced_read_reg (regs, dsc, 3);
- /* Preload instructions:
+ pc_val = displaced_read_reg (regs, dsc, ARM_PC_REGNUM);
- {pli/pld} [rn, #+/-imm]
- ->
- {pli/pld} [r0, #+/-imm]. */
+ pc_val = pc_val & 0xfffffffc;
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- rn_val = displaced_read_reg (regs, from, rn);
- displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, pc_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 3, imm12, CANNOT_WRITE_PC);
- dsc->u.preload.immed = 1;
+ dsc->rd = rt;
- dsc->modinsn[0] = insn & 0xfff0ffff;
+ dsc->u.ldst.xfersize = size;
+ dsc->u.ldst.immed = 0;
+ dsc->u.ldst.writeback = 0;
+ dsc->u.ldst.restore_r4 = 0;
- dsc->cleanup = &cleanup_preload;
+ /* LDR R0, R2, R3 */
+ dsc->modinsn[0] = 0xf852;
+ dsc->modinsn[1] = 0x3;
+ dsc->numinsns = 2;
+
+ dsc->cleanup = &cleanup_load;
return 0;
}
-/* Preload instructions with register offset. */
-
static int
-copy_preload_reg (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
+thumb2_copy_load_reg_imm (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc,
+ int writeback, int immed)
{
- unsigned int rn = bits (insn, 16, 19);
- unsigned int rm = bits (insn, 0, 3);
- ULONGEST rn_val, rm_val;
- CORE_ADDR from = dsc->insn_addr;
+ unsigned int rt = bits (insn2, 12, 15);
+ unsigned int rn = bits (insn1, 0, 3);
+ unsigned int rm = bits (insn2, 0, 3); /* Only valid if !immed. */
+ /* In LDR (register), there is also a register Rm, which is not allowed to
+ be PC, so we don't have to check it. */
- if (!insn_references_pc (insn, 0x000f000ful))
- return copy_unmodified (gdbarch, insn, "preload reg", dsc);
+ if (rt != ARM_PC_REGNUM && rn != ARM_PC_REGNUM)
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "load",
+ dsc);
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying preload insn %.8lx\n",
- (unsigned long) insn);
-
- /* Preload register-offset instructions:
-
- {pli/pld} [rn, rm {, shift}]
- ->
- {pli/pld} [r0, r1 {, shift}]. */
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying ldr r%d [r%d] insn %.4x%.4x\n",
+ rt, rn, insn1, insn2);
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[1] = displaced_read_reg (regs, from, 1);
- rn_val = displaced_read_reg (regs, from, rn);
- rm_val = displaced_read_reg (regs, from, rm);
- displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 1, rm_val, CANNOT_WRITE_PC);
+ install_load_store (gdbarch, regs, dsc, 1, immed, writeback, 4,
+ 0, rt, rm, rn);
- dsc->u.preload.immed = 0;
+ dsc->u.ldst.restore_r4 = 0;
- dsc->modinsn[0] = (insn & 0xfff0fff0) | 0x1;
+ if (immed)
+ /* ldr[b]<cond> rt, [rn, #imm], etc.
+ ->
+ ldr[b]<cond> r0, [r2, #imm]. */
+ {
+ dsc->modinsn[0] = (insn1 & 0xfff0) | 0x2;
+ dsc->modinsn[1] = insn2 & 0x0fff;
+ }
+ else
+ /* ldr[b]<cond> rt, [rn, rm], etc.
+ ->
+ ldr[b]<cond> r0, [r2, r3]. */
+ {
+ dsc->modinsn[0] = (insn1 & 0xfff0) | 0x2;
+ dsc->modinsn[1] = (insn2 & 0x0ff0) | 0x3;
+ }
- dsc->cleanup = &cleanup_preload;
+ dsc->numinsns = 2;
return 0;
}
-/* Copy/cleanup coprocessor load and store instructions. */
-
-static void
-cleanup_copro_load_store (struct gdbarch *gdbarch,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
-{
- ULONGEST rn_val = displaced_read_reg (regs, dsc->insn_addr, 0);
-
- displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
-
- if (dsc->u.ldst.writeback)
- displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, LOAD_WRITE_PC);
-}
static int
-copy_copro_load_store (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
+arm_copy_ldr_str_ldrb_strb (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc,
+ int load, int size, int usermode)
{
+ int immed = !bit (insn, 25);
+ int writeback = (bit (insn, 24) == 0 || bit (insn, 21) != 0);
+ unsigned int rt = bits (insn, 12, 15);
unsigned int rn = bits (insn, 16, 19);
- ULONGEST rn_val;
- CORE_ADDR from = dsc->insn_addr;
+ unsigned int rm = bits (insn, 0, 3); /* Only valid if !immed. */
- if (!insn_references_pc (insn, 0x000f0000ul))
- return copy_unmodified (gdbarch, insn, "copro load/store", dsc);
+ if (!insn_references_pc (insn, 0x000ff00ful))
+ return arm_copy_unmodified (gdbarch, insn, "load/store", dsc);
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying coprocessor "
- "load/store insn %.8lx\n", (unsigned long) insn);
-
- /* Coprocessor load/store instructions:
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying %s%s r%d [r%d] insn %.8lx\n",
+ load ? (size == 1 ? "ldrb" : "ldr")
+ : (size == 1 ? "strb" : "str"), usermode ? "t" : "",
+ rt, rn,
+ (unsigned long) insn);
- {stc/stc2} [<Rn>, #+/-imm] (and other immediate addressing modes)
- ->
- {stc/stc2} [r0, #+/-imm].
+ install_load_store (gdbarch, regs, dsc, load, immed, writeback, size,
+ usermode, rt, rm, rn);
- ldc/ldc2 are handled identically. */
+ if (load || rt != ARM_PC_REGNUM)
+ {
+ dsc->u.ldst.restore_r4 = 0;
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- rn_val = displaced_read_reg (regs, from, rn);
- displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
+ if (immed)
+ /* {ldr,str}[b]<cond> rt, [rn, #imm], etc.
+ ->
+ {ldr,str}[b]<cond> r0, [r2, #imm]. */
+ dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000;
+ else
+ /* {ldr,str}[b]<cond> rt, [rn, rm], etc.
+ ->
+ {ldr,str}[b]<cond> r0, [r2, r3]. */
+ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003;
+ }
+ else
+ {
+ /* We need to use r4 as scratch. Make sure it's restored afterwards. */
+ dsc->u.ldst.restore_r4 = 1;
+ dsc->modinsn[0] = 0xe92d8000; /* push {pc} */
+ dsc->modinsn[1] = 0xe8bd0010; /* pop {r4} */
+ dsc->modinsn[2] = 0xe044400f; /* sub r4, r4, pc. */
+ dsc->modinsn[3] = 0xe2844008; /* add r4, r4, #8. */
+ dsc->modinsn[4] = 0xe0800004; /* add r0, r0, r4. */
- dsc->u.ldst.writeback = bit (insn, 25);
- dsc->u.ldst.rn = rn;
+ /* As above. */
+ if (immed)
+ dsc->modinsn[5] = (insn & 0xfff00fff) | 0x20000;
+ else
+ dsc->modinsn[5] = (insn & 0xfff00ff0) | 0x20003;
- dsc->modinsn[0] = insn & 0xfff0ffff;
+ dsc->numinsns = 6;
+ }
- dsc->cleanup = &cleanup_copro_load_store;
+ dsc->cleanup = load ? &cleanup_load : &cleanup_store;
return 0;
}
-/* Clean up branch instructions (actually perform the branch, by setting
- PC). */
-
-static void
-cleanup_branch (struct gdbarch *gdbarch, struct regcache *regs,
- struct displaced_step_closure *dsc)
-{
- ULONGEST from = dsc->insn_addr;
- uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
- int branch_taken = condition_true (dsc->u.branch.cond, status);
- enum pc_write_style write_pc = dsc->u.branch.exchange
- ? BX_WRITE_PC : BRANCH_WRITE_PC;
+/* Cleanup LDM instructions with fully-populated register list. This is an
+ unfortunate corner case: it's impossible to implement correctly by modifying
+ the instruction. The issue is as follows: we have an instruction,
- if (!branch_taken)
- return;
+ ldm rN, {r0-r15}
- if (dsc->u.branch.link)
- {
- ULONGEST pc = displaced_read_reg (regs, from, 15);
- displaced_write_reg (regs, dsc, 14, pc - 4, CANNOT_WRITE_PC);
- }
+ which we must rewrite to avoid loading PC. A possible solution would be to
+ do the load in two halves, something like (with suitable cleanup
+ afterwards):
- displaced_write_reg (regs, dsc, 15, dsc->u.branch.dest, write_pc);
-}
+ mov r8, rN
+ ldm[id][ab] r8!, {r0-r7}
+ str r7, <temp>
+ ldm[id][ab] r8, {r7-r14}
+ <bkpt>
-/* Copy B/BL/BLX instructions with immediate destinations. */
+ but at present there's no suitable place for <temp>, since the scratch space
+ is overwritten before the cleanup routine is called. For now, we simply
+ emulate the instruction. */
-static int
-copy_b_bl_blx (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs, struct displaced_step_closure *dsc)
+static void
+cleanup_block_load_all (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- unsigned int cond = bits (insn, 28, 31);
- int exchange = (cond == 0xf);
- int link = exchange || bit (insn, 24);
- CORE_ADDR from = dsc->insn_addr;
- long offset;
+ int inc = dsc->u.block.increment;
+ int bump_before = dsc->u.block.before ? (inc ? 4 : -4) : 0;
+ int bump_after = dsc->u.block.before ? 0 : (inc ? 4 : -4);
+ uint32_t regmask = dsc->u.block.regmask;
+ int regno = inc ? 0 : 15;
+ CORE_ADDR xfer_addr = dsc->u.block.xfer_addr;
+ int exception_return = dsc->u.block.load && dsc->u.block.user
+ && (regmask & 0x8000) != 0;
+ uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM);
+ int do_transfer = condition_true (dsc->u.block.cond, status);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying %s immediate insn "
- "%.8lx\n", (exchange) ? "blx" : (link) ? "bl" : "b",
- (unsigned long) insn);
+ if (!do_transfer)
+ return;
- /* Implement "BL<cond> <label>" as:
+ /* If the instruction is ldm rN, {...pc}^, I don't think there's anything
+ sensible we can do here. Complain loudly. */
+ if (exception_return)
+ error (_("Cannot single-step exception return"));
- Preparation: cond <- instruction condition
- Insn: mov r0, r0 (nop)
- Cleanup: if (condition true) { r14 <- pc; pc <- label }.
+ /* We don't handle any stores here for now. */
+ gdb_assert (dsc->u.block.load != 0);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: emulating block transfer: "
+ "%s %s %s\n", dsc->u.block.load ? "ldm" : "stm",
+ dsc->u.block.increment ? "inc" : "dec",
+ dsc->u.block.before ? "before" : "after");
- B<cond> similar, but don't set r14 in cleanup. */
+ while (regmask)
+ {
+ uint32_t memword;
- if (exchange)
- /* For BLX, set bit 0 of the destination. The cleanup_branch function will
- then arrange the switch into Thumb mode. */
- offset = (bits (insn, 0, 23) << 2) | (bit (insn, 24) << 1) | 1;
- else
- offset = bits (insn, 0, 23) << 2;
+ if (inc)
+ while (regno <= ARM_PC_REGNUM && (regmask & (1 << regno)) == 0)
+ regno++;
+ else
+ while (regno >= 0 && (regmask & (1 << regno)) == 0)
+ regno--;
- if (bit (offset, 25))
- offset = offset | ~0x3ffffff;
+ xfer_addr += bump_before;
- dsc->u.branch.cond = cond;
- dsc->u.branch.link = link;
- dsc->u.branch.exchange = exchange;
- dsc->u.branch.dest = from + 8 + offset;
+ memword = read_memory_unsigned_integer (xfer_addr, 4, byte_order);
+ displaced_write_reg (regs, dsc, regno, memword, LOAD_WRITE_PC);
- dsc->modinsn[0] = ARM_NOP;
+ xfer_addr += bump_after;
- dsc->cleanup = &cleanup_branch;
+ regmask &= ~(1 << regno);
+ }
- return 0;
+ if (dsc->u.block.writeback)
+ displaced_write_reg (regs, dsc, dsc->u.block.rn, xfer_addr,
+ CANNOT_WRITE_PC);
}
-/* Copy BX/BLX with register-specified destinations. */
+/* Clean up an STM which included the PC in the register list. */
-static int
-copy_bx_blx_reg (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs, struct displaced_step_closure *dsc)
+static void
+cleanup_block_store_pc (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- unsigned int cond = bits (insn, 28, 31);
- /* BX: x12xxx1x
- BLX: x12xxx3x. */
- int link = bit (insn, 5);
- unsigned int rm = bits (insn, 0, 3);
- CORE_ADDR from = dsc->insn_addr;
-
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying %s register insn "
- "%.8lx\n", (link) ? "blx" : "bx",
- (unsigned long) insn);
-
- /* Implement {BX,BLX}<cond> <reg>" as:
+ uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM);
+ int store_executed = condition_true (dsc->u.block.cond, status);
+ CORE_ADDR pc_stored_at, transferred_regs = bitcount (dsc->u.block.regmask);
+ CORE_ADDR stm_insn_addr;
+ uint32_t pc_val;
+ long offset;
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- Preparation: cond <- instruction condition
- Insn: mov r0, r0 (nop)
- Cleanup: if (condition true) { r14 <- pc; pc <- dest; }.
+ /* If condition code fails, there's nothing else to do. */
+ if (!store_executed)
+ return;
- Don't set r14 in cleanup for BX. */
+ if (dsc->u.block.increment)
+ {
+ pc_stored_at = dsc->u.block.xfer_addr + 4 * transferred_regs;
- dsc->u.branch.dest = displaced_read_reg (regs, from, rm);
+ if (dsc->u.block.before)
+ pc_stored_at += 4;
+ }
+ else
+ {
+ pc_stored_at = dsc->u.block.xfer_addr;
- dsc->u.branch.cond = cond;
- dsc->u.branch.link = link;
- dsc->u.branch.exchange = 1;
+ if (dsc->u.block.before)
+ pc_stored_at -= 4;
+ }
- dsc->modinsn[0] = ARM_NOP;
+ pc_val = read_memory_unsigned_integer (pc_stored_at, 4, byte_order);
+ stm_insn_addr = dsc->scratch_base;
+ offset = pc_val - stm_insn_addr;
- dsc->cleanup = &cleanup_branch;
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: detected PC offset %.8lx for "
+ "STM instruction\n", offset);
- return 0;
+ /* Rewrite the stored PC to the proper value for the non-displaced original
+ instruction. */
+ write_memory_unsigned_integer (pc_stored_at, 4, byte_order,
+ dsc->insn_addr + offset);
}
-/* Copy/cleanup arithmetic/logic instruction with immediate RHS. */
+/* Clean up an LDM which includes the PC in the register list. We clumped all
+ the registers in the transferred list into a contiguous range r0...rX (to
+ avoid loading PC directly and losing control of the debugged program), so we
+ must undo that here. */
static void
-cleanup_alu_imm (struct gdbarch *gdbarch,
- struct regcache *regs, struct displaced_step_closure *dsc)
+cleanup_block_load_pc (struct gdbarch *gdbarch,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- ULONGEST rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
- displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
-}
+ uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM);
+ int load_executed = condition_true (dsc->u.block.cond, status), i;
+ unsigned int mask = dsc->u.block.regmask, write_reg = ARM_PC_REGNUM;
+ unsigned int regs_loaded = bitcount (mask);
+ unsigned int num_to_shuffle = regs_loaded, clobbered;
-static int
-copy_alu_imm (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
- struct displaced_step_closure *dsc)
-{
- unsigned int rn = bits (insn, 16, 19);
- unsigned int rd = bits (insn, 12, 15);
- unsigned int op = bits (insn, 21, 24);
- int is_mov = (op == 0xd);
- ULONGEST rd_val, rn_val;
- CORE_ADDR from = dsc->insn_addr;
+ /* The method employed here will fail if the register list is fully populated
+ (we need to avoid loading PC directly). */
+ gdb_assert (num_to_shuffle < 16);
- if (!insn_references_pc (insn, 0x000ff000ul))
- return copy_unmodified (gdbarch, insn, "ALU immediate", dsc);
+ if (!load_executed)
+ return;
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying immediate %s insn "
- "%.8lx\n", is_mov ? "move" : "ALU",
- (unsigned long) insn);
+ clobbered = (1 << num_to_shuffle) - 1;
- /* Instruction is of form:
+ while (num_to_shuffle > 0)
+ {
+ if ((mask & (1 << write_reg)) != 0)
+ {
+ unsigned int read_reg = num_to_shuffle - 1;
- <op><cond> rd, [rn,] #imm
+ if (read_reg != write_reg)
+ {
+ ULONGEST rval = displaced_read_reg (regs, dsc, read_reg);
+ displaced_write_reg (regs, dsc, write_reg, rval, LOAD_WRITE_PC);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: move "
+ "loaded register r%d to r%d\n"), read_reg,
+ write_reg);
+ }
+ else if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: register "
+ "r%d already in the right place\n"),
+ write_reg);
- Rewrite as:
+ clobbered &= ~(1 << write_reg);
- Preparation: tmp1, tmp2 <- r0, r1;
- r0, r1 <- rd, rn
- Insn: <op><cond> r0, r1, #imm
- Cleanup: rd <- r0; r0 <- tmp1; r1 <- tmp2
- */
+ num_to_shuffle--;
+ }
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[1] = displaced_read_reg (regs, from, 1);
- rn_val = displaced_read_reg (regs, from, rn);
- rd_val = displaced_read_reg (regs, from, rd);
- displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
- dsc->rd = rd;
+ write_reg--;
+ }
- if (is_mov)
- dsc->modinsn[0] = insn & 0xfff00fff;
- else
- dsc->modinsn[0] = (insn & 0xfff00fff) | 0x10000;
+ /* Restore any registers we scribbled over. */
+ for (write_reg = 0; clobbered != 0; write_reg++)
+ {
+ if ((clobbered & (1 << write_reg)) != 0)
+ {
+ displaced_write_reg (regs, dsc, write_reg, dsc->tmp[write_reg],
+ CANNOT_WRITE_PC);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: restored "
+ "clobbered register r%d\n"), write_reg);
+ clobbered &= ~(1 << write_reg);
+ }
+ }
- dsc->cleanup = &cleanup_alu_imm;
+ /* Perform register writeback manually. */
+ if (dsc->u.block.writeback)
+ {
+ ULONGEST new_rn_val = dsc->u.block.xfer_addr;
- return 0;
+ if (dsc->u.block.increment)
+ new_rn_val += regs_loaded * 4;
+ else
+ new_rn_val -= regs_loaded * 4;
+
+ displaced_write_reg (regs, dsc, dsc->u.block.rn, new_rn_val,
+ CANNOT_WRITE_PC);
+ }
}
-/* Copy/cleanup arithmetic/logic insns with register RHS. */
+/* Handle ldm/stm, apart from some tricky cases which are unlikely to occur
+ in user-level code (in particular exception return, ldm rn, {...pc}^). */
-static void
-cleanup_alu_reg (struct gdbarch *gdbarch,
- struct regcache *regs, struct displaced_step_closure *dsc)
+static int
+arm_copy_block_xfer (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- ULONGEST rd_val;
- int i;
+ int load = bit (insn, 20);
+ int user = bit (insn, 22);
+ int increment = bit (insn, 23);
+ int before = bit (insn, 24);
+ int writeback = bit (insn, 21);
+ int rn = bits (insn, 16, 19);
- rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
+ /* Block transfers which don't mention PC can be run directly
+ out-of-line. */
+ if (rn != ARM_PC_REGNUM && (insn & 0x8000) == 0)
+ return arm_copy_unmodified (gdbarch, insn, "ldm/stm", dsc);
- for (i = 0; i < 3; i++)
- displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC);
+ if (rn == ARM_PC_REGNUM)
+ {
+ warning (_("displaced: Unpredictable LDM or STM with "
+ "base register r15"));
+ return arm_copy_unmodified (gdbarch, insn, "unpredictable ldm/stm", dsc);
+ }
- displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
-}
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying block transfer insn "
+ "%.8lx\n", (unsigned long) insn);
-static int
-copy_alu_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
- struct displaced_step_closure *dsc)
-{
- unsigned int rn = bits (insn, 16, 19);
- unsigned int rm = bits (insn, 0, 3);
- unsigned int rd = bits (insn, 12, 15);
- unsigned int op = bits (insn, 21, 24);
- int is_mov = (op == 0xd);
- ULONGEST rd_val, rn_val, rm_val;
- CORE_ADDR from = dsc->insn_addr;
+ dsc->u.block.xfer_addr = displaced_read_reg (regs, dsc, rn);
+ dsc->u.block.rn = rn;
+
+ dsc->u.block.load = load;
+ dsc->u.block.user = user;
+ dsc->u.block.increment = increment;
+ dsc->u.block.before = before;
+ dsc->u.block.writeback = writeback;
+ dsc->u.block.cond = bits (insn, 28, 31);
+
+ dsc->u.block.regmask = insn & 0xffff;
+
+ if (load)
+ {
+ if ((insn & 0xffff) == 0xffff)
+ {
+ /* LDM with a fully-populated register list. This case is
+ particularly tricky. Implement for now by fully emulating the
+ instruction (which might not behave perfectly in all cases, but
+ these instructions should be rare enough for that not to matter
+ too much). */
+ dsc->modinsn[0] = ARM_NOP;
+
+ dsc->cleanup = &cleanup_block_load_all;
+ }
+ else
+ {
+ /* LDM of a list of registers which includes PC. Implement by
+ rewriting the list of registers to be transferred into a
+ contiguous chunk r0...rX before doing the transfer, then shuffling
+ registers into the correct places in the cleanup routine. */
+ unsigned int regmask = insn & 0xffff;
+ unsigned int num_in_list = bitcount (regmask), new_regmask, bit = 1;
+ unsigned int to = 0, from = 0, i, new_rn;
- if (!insn_references_pc (insn, 0x000ff00ful))
- return copy_unmodified (gdbarch, insn, "ALU reg", dsc);
+ for (i = 0; i < num_in_list; i++)
+ dsc->tmp[i] = displaced_read_reg (regs, dsc, i);
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying reg %s insn %.8lx\n",
- is_mov ? "move" : "ALU", (unsigned long) insn);
+ /* Writeback makes things complicated. We need to avoid clobbering
+ the base register with one of the registers in our modified
+ register list, but just using a different register can't work in
+ all cases, e.g.:
- /* Instruction is of form:
+ ldm r14!, {r0-r13,pc}
- <op><cond> rd, [rn,] rm [, <shift>]
+ which would need to be rewritten as:
- Rewrite as:
+ ldm rN!, {r0-r14}
- Preparation: tmp1, tmp2, tmp3 <- r0, r1, r2;
- r0, r1, r2 <- rd, rn, rm
- Insn: <op><cond> r0, r1, r2 [, <shift>]
- Cleanup: rd <- r0; r0, r1, r2 <- tmp1, tmp2, tmp3
- */
+ but that can't work, because there's no free register for N.
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[1] = displaced_read_reg (regs, from, 1);
- dsc->tmp[2] = displaced_read_reg (regs, from, 2);
- rd_val = displaced_read_reg (regs, from, rd);
- rn_val = displaced_read_reg (regs, from, rn);
- rm_val = displaced_read_reg (regs, from, rm);
- displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
- dsc->rd = rd;
+ Solve this by turning off the writeback bit, and emulating
+ writeback manually in the cleanup routine. */
- if (is_mov)
- dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x2;
- else
- dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x10002;
+ if (writeback)
+ insn &= ~(1 << 21);
- dsc->cleanup = &cleanup_alu_reg;
+ new_regmask = (1 << num_in_list) - 1;
- return 0;
-}
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: LDM r%d%s, "
+ "{..., pc}: original reg list %.4x, modified "
+ "list %.4x\n"), rn, writeback ? "!" : "",
+ (int) insn & 0xffff, new_regmask);
-/* Cleanup/copy arithmetic/logic insns with shifted register RHS. */
+ dsc->modinsn[0] = (insn & ~0xffff) | (new_regmask & 0xffff);
-static void
-cleanup_alu_shifted_reg (struct gdbarch *gdbarch,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
-{
- ULONGEST rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
- int i;
+ dsc->cleanup = &cleanup_block_load_pc;
+ }
+ }
+ else
+ {
+ /* STM of a list of registers which includes PC. Run the instruction
+ as-is, but out of line: this will store the wrong value for the PC,
+ so we must manually fix up the memory in the cleanup routine.
+ Doing things this way has the advantage that we can auto-detect
+ the offset of the PC write (which is architecture-dependent) in
+ the cleanup routine. */
+ dsc->modinsn[0] = insn;
- for (i = 0; i < 4; i++)
- displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC);
+ dsc->cleanup = &cleanup_block_store_pc;
+ }
- displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
+ return 0;
}
static int
-copy_alu_shifted_reg (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
+thumb2_copy_block_xfer (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- unsigned int rn = bits (insn, 16, 19);
- unsigned int rm = bits (insn, 0, 3);
- unsigned int rd = bits (insn, 12, 15);
- unsigned int rs = bits (insn, 8, 11);
- unsigned int op = bits (insn, 21, 24);
- int is_mov = (op == 0xd), i;
- ULONGEST rd_val, rn_val, rm_val, rs_val;
- CORE_ADDR from = dsc->insn_addr;
+ int rn = bits (insn1, 0, 3);
+ int load = bit (insn1, 4);
+ int writeback = bit (insn1, 5);
- if (!insn_references_pc (insn, 0x000fff0ful))
- return copy_unmodified (gdbarch, insn, "ALU shifted reg", dsc);
+ /* Block transfers which don't mention PC can be run directly
+ out-of-line. */
+ if (rn != ARM_PC_REGNUM && (insn2 & 0x8000) == 0)
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "ldm/stm", dsc);
+
+ if (rn == ARM_PC_REGNUM)
+ {
+ warning (_("displaced: Unpredictable LDM or STM with "
+ "base register r15"));
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "unpredictable ldm/stm", dsc);
+ }
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying shifted reg %s insn "
- "%.8lx\n", is_mov ? "move" : "ALU",
- (unsigned long) insn);
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying block transfer insn "
+ "%.4x%.4x\n", insn1, insn2);
- /* Instruction is of form:
+ /* Clear bit 13, since it should be always zero. */
+ dsc->u.block.regmask = (insn2 & 0xdfff);
+ dsc->u.block.rn = rn;
- <op><cond> rd, [rn,] rm, <shift> rs
+ dsc->u.block.load = load;
+ dsc->u.block.user = 0;
+ dsc->u.block.increment = bit (insn1, 7);
+ dsc->u.block.before = bit (insn1, 8);
+ dsc->u.block.writeback = writeback;
+ dsc->u.block.cond = INST_AL;
+ dsc->u.block.xfer_addr = displaced_read_reg (regs, dsc, rn);
- Rewrite as:
+ if (load)
+ {
+ if (dsc->u.block.regmask == 0xffff)
+ {
+ /* This branch is impossible to happen. */
+ gdb_assert (0);
+ }
+ else
+ {
+ unsigned int regmask = dsc->u.block.regmask;
+ unsigned int num_in_list = bitcount (regmask), new_regmask, bit = 1;
+ unsigned int to = 0, from = 0, i, new_rn;
- Preparation: tmp1, tmp2, tmp3, tmp4 <- r0, r1, r2, r3
- r0, r1, r2, r3 <- rd, rn, rm, rs
- Insn: <op><cond> r0, r1, r2, <shift> r3
- Cleanup: tmp5 <- r0
- r0, r1, r2, r3 <- tmp1, tmp2, tmp3, tmp4
- rd <- tmp5
- */
+ for (i = 0; i < num_in_list; i++)
+ dsc->tmp[i] = displaced_read_reg (regs, dsc, i);
- for (i = 0; i < 4; i++)
- dsc->tmp[i] = displaced_read_reg (regs, from, i);
+ if (writeback)
+ insn1 &= ~(1 << 5);
- rd_val = displaced_read_reg (regs, from, rd);
- rn_val = displaced_read_reg (regs, from, rn);
- rm_val = displaced_read_reg (regs, from, rm);
- rs_val = displaced_read_reg (regs, from, rs);
- displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 3, rs_val, CANNOT_WRITE_PC);
- dsc->rd = rd;
+ new_regmask = (1 << num_in_list) - 1;
- if (is_mov)
- dsc->modinsn[0] = (insn & 0xfff000f0) | 0x302;
- else
- dsc->modinsn[0] = (insn & 0xfff000f0) | 0x10302;
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: LDM r%d%s, "
+ "{..., pc}: original reg list %.4x, modified "
+ "list %.4x\n"), rn, writeback ? "!" : "",
+ (int) dsc->u.block.regmask, new_regmask);
- dsc->cleanup = &cleanup_alu_shifted_reg;
+ dsc->modinsn[0] = insn1;
+ dsc->modinsn[1] = (new_regmask & 0xffff);
+ dsc->numinsns = 2;
+ dsc->cleanup = &cleanup_block_load_pc;
+ }
+ }
+ else
+ {
+ dsc->modinsn[0] = insn1;
+ dsc->modinsn[1] = insn2;
+ dsc->numinsns = 2;
+ dsc->cleanup = &cleanup_block_store_pc;
+ }
return 0;
}
-/* Clean up load instructions. */
+/* Cleanup/copy SVC (SWI) instructions. These two functions are overridden
+ for Linux, where some SVC instructions must be treated specially. */
static void
-cleanup_load (struct gdbarch *gdbarch, struct regcache *regs,
- struct displaced_step_closure *dsc)
+cleanup_svc (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- ULONGEST rt_val, rt_val2 = 0, rn_val;
- CORE_ADDR from = dsc->insn_addr;
+ CORE_ADDR resume_addr = dsc->insn_addr + dsc->insn_size;
- rt_val = displaced_read_reg (regs, from, 0);
- if (dsc->u.ldst.xfersize == 8)
- rt_val2 = displaced_read_reg (regs, from, 1);
- rn_val = displaced_read_reg (regs, from, 2);
-
- displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
- if (dsc->u.ldst.xfersize > 4)
- displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC);
- if (!dsc->u.ldst.immed)
- displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: cleanup for svc, resume at "
+ "%.8lx\n", (unsigned long) resume_addr);
- /* Handle register writeback. */
- if (dsc->u.ldst.writeback)
- displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC);
- /* Put result in right place. */
- displaced_write_reg (regs, dsc, dsc->rd, rt_val, LOAD_WRITE_PC);
- if (dsc->u.ldst.xfersize == 8)
- displaced_write_reg (regs, dsc, dsc->rd + 1, rt_val2, LOAD_WRITE_PC);
+ displaced_write_reg (regs, dsc, ARM_PC_REGNUM, resume_addr, BRANCH_WRITE_PC);
}
-/* Clean up store instructions. */
-static void
-cleanup_store (struct gdbarch *gdbarch, struct regcache *regs,
- struct displaced_step_closure *dsc)
+/* Common copy routine for svc instruciton. */
+
+static int
+install_svc (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- CORE_ADDR from = dsc->insn_addr;
- ULONGEST rn_val = displaced_read_reg (regs, from, 2);
+ /* Preparation: none.
+ Insn: unmodified svc.
+ Cleanup: pc <- insn_addr + insn_size. */
- displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
- if (dsc->u.ldst.xfersize > 4)
- displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC);
- if (!dsc->u.ldst.immed)
- displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC);
- if (!dsc->u.ldst.restore_r4)
- displaced_write_reg (regs, dsc, 4, dsc->tmp[4], CANNOT_WRITE_PC);
+ /* Pretend we wrote to the PC, so cleanup doesn't set PC to the next
+ instruction. */
+ dsc->wrote_to_pc = 1;
- /* Writeback. */
- if (dsc->u.ldst.writeback)
- displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC);
+ /* Allow OS-specific code to override SVC handling. */
+ if (dsc->u.svc.copy_svc_os)
+ return dsc->u.svc.copy_svc_os (gdbarch, regs, dsc);
+ else
+ {
+ dsc->cleanup = &cleanup_svc;
+ return 0;
+ }
}
-/* Copy "extra" load/store instructions. These are halfword/doubleword
- transfers, which have a different encoding to byte/word transfers. */
-
static int
-copy_extra_ld_st (struct gdbarch *gdbarch, uint32_t insn, int unpriveleged,
- struct regcache *regs, struct displaced_step_closure *dsc)
+arm_copy_svc (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
{
- unsigned int op1 = bits (insn, 20, 24);
- unsigned int op2 = bits (insn, 5, 6);
- unsigned int rt = bits (insn, 12, 15);
- unsigned int rn = bits (insn, 16, 19);
- unsigned int rm = bits (insn, 0, 3);
- char load[12] = {0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1};
- char bytesize[12] = {2, 2, 2, 2, 8, 1, 8, 1, 8, 2, 8, 2};
- int immed = (op1 & 0x4) != 0;
- int opcode;
- ULONGEST rt_val, rt_val2 = 0, rn_val, rm_val = 0;
- CORE_ADDR from = dsc->insn_addr;
-
- if (!insn_references_pc (insn, 0x000ff00ful))
- return copy_unmodified (gdbarch, insn, "extra load/store", dsc);
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying %sextra load/store "
- "insn %.8lx\n", unpriveleged ? "unpriveleged " : "",
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying svc insn %.8lx\n",
(unsigned long) insn);
- opcode = ((op2 << 2) | (op1 & 0x1) | ((op1 & 0x4) >> 1)) - 4;
+ dsc->modinsn[0] = insn;
- if (opcode < 0)
- internal_error (__FILE__, __LINE__,
- _("copy_extra_ld_st: instruction decode error"));
+ return install_svc (gdbarch, regs, dsc);
+}
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[1] = displaced_read_reg (regs, from, 1);
- dsc->tmp[2] = displaced_read_reg (regs, from, 2);
- if (!immed)
- dsc->tmp[3] = displaced_read_reg (regs, from, 3);
+static int
+thumb_copy_svc (struct gdbarch *gdbarch, uint16_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
- rt_val = displaced_read_reg (regs, from, rt);
- if (bytesize[opcode] == 8)
- rt_val2 = displaced_read_reg (regs, from, rt + 1);
- rn_val = displaced_read_reg (regs, from, rn);
- if (!immed)
- rm_val = displaced_read_reg (regs, from, rm);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying svc insn %.4x\n",
+ insn);
- displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
- if (bytesize[opcode] == 8)
- displaced_write_reg (regs, dsc, 1, rt_val2, CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC);
- if (!immed)
- displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC);
+ dsc->modinsn[0] = insn;
- dsc->rd = rt;
- dsc->u.ldst.xfersize = bytesize[opcode];
- dsc->u.ldst.rn = rn;
- dsc->u.ldst.immed = immed;
- dsc->u.ldst.writeback = bit (insn, 24) == 0 || bit (insn, 21) != 0;
- dsc->u.ldst.restore_r4 = 0;
+ return install_svc (gdbarch, regs, dsc);
+}
- if (immed)
- /* {ldr,str}<width><cond> rt, [rt2,] [rn, #imm]
- ->
- {ldr,str}<width><cond> r0, [r1,] [r2, #imm]. */
- dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000;
- else
- /* {ldr,str}<width><cond> rt, [rt2,] [rn, +/-rm]
- ->
- {ldr,str}<width><cond> r0, [r1,] [r2, +/-r3]. */
- dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003;
+/* Copy undefined instructions. */
- dsc->cleanup = load[opcode] ? &cleanup_load : &cleanup_store;
+static int
+arm_copy_undef (struct gdbarch *gdbarch, uint32_t insn,
+ struct displaced_step_closure *dsc)
+{
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying undefined insn %.8lx\n",
+ (unsigned long) insn);
+
+ dsc->modinsn[0] = insn;
return 0;
}
-/* Copy byte/word loads and stores. */
-
static int
-copy_ldr_str_ldrb_strb (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs,
- struct displaced_step_closure *dsc, int load, int byte,
- int usermode)
+thumb_32bit_copy_undef (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2,
+ struct displaced_step_closure *dsc)
{
- int immed = !bit (insn, 25);
- unsigned int rt = bits (insn, 12, 15);
- unsigned int rn = bits (insn, 16, 19);
- unsigned int rm = bits (insn, 0, 3); /* Only valid if !immed. */
- ULONGEST rt_val, rn_val, rm_val = 0;
- CORE_ADDR from = dsc->insn_addr;
-
- if (!insn_references_pc (insn, 0x000ff00ful))
- return copy_unmodified (gdbarch, insn, "load/store", dsc);
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying %s%s insn %.8lx\n",
- load ? (byte ? "ldrb" : "ldr")
- : (byte ? "strb" : "str"), usermode ? "t" : "",
- (unsigned long) insn);
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying undefined insn "
+ "%.4x %.4x\n", (unsigned short) insn1,
+ (unsigned short) insn2);
- dsc->tmp[0] = displaced_read_reg (regs, from, 0);
- dsc->tmp[2] = displaced_read_reg (regs, from, 2);
- if (!immed)
- dsc->tmp[3] = displaced_read_reg (regs, from, 3);
- if (!load)
- dsc->tmp[4] = displaced_read_reg (regs, from, 4);
+ dsc->modinsn[0] = insn1;
+ dsc->modinsn[1] = insn2;
+ dsc->numinsns = 2;
- rt_val = displaced_read_reg (regs, from, rt);
- rn_val = displaced_read_reg (regs, from, rn);
- if (!immed)
- rm_val = displaced_read_reg (regs, from, rm);
+ return 0;
+}
- displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
- displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC);
- if (!immed)
- displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC);
+/* Copy unpredictable instructions. */
- dsc->rd = rt;
- dsc->u.ldst.xfersize = byte ? 1 : 4;
- dsc->u.ldst.rn = rn;
- dsc->u.ldst.immed = immed;
- dsc->u.ldst.writeback = bit (insn, 24) == 0 || bit (insn, 21) != 0;
+static int
+arm_copy_unpred (struct gdbarch *gdbarch, uint32_t insn,
+ struct displaced_step_closure *dsc)
+{
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying unpredictable insn "
+ "%.8lx\n", (unsigned long) insn);
- /* To write PC we can do:
+ dsc->modinsn[0] = insn;
- scratch+0: str pc, temp (*temp = scratch + 8 + offset)
- scratch+4: ldr r4, temp
- scratch+8: sub r4, r4, pc (r4 = scratch + 8 + offset - scratch - 8 - 8)
- scratch+12: add r4, r4, #8 (r4 = offset)
- scratch+16: add r0, r0, r4
- scratch+20: str r0, [r2, #imm] (or str r0, [r2, r3])
- scratch+24: <temp>
+ return 0;
+}
- Otherwise we don't know what value to write for PC, since the offset is
- architecture-dependent (sometimes PC+8, sometimes PC+12). */
+/* The decode_* functions are instruction decoding helpers. They mostly follow
+ the presentation in the ARM ARM. */
- if (load || rt != 15)
- {
- dsc->u.ldst.restore_r4 = 0;
+static int
+arm_decode_misc_memhint_neon (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int op1 = bits (insn, 20, 26), op2 = bits (insn, 4, 7);
+ unsigned int rn = bits (insn, 16, 19);
- if (immed)
- /* {ldr,str}[b]<cond> rt, [rn, #imm], etc.
- ->
- {ldr,str}[b]<cond> r0, [r2, #imm]. */
- dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000;
+ if (op1 == 0x10 && (op2 & 0x2) == 0x0 && (rn & 0xe) == 0x0)
+ return arm_copy_unmodified (gdbarch, insn, "cps", dsc);
+ else if (op1 == 0x10 && op2 == 0x0 && (rn & 0xe) == 0x1)
+ return arm_copy_unmodified (gdbarch, insn, "setend", dsc);
+ else if ((op1 & 0x60) == 0x20)
+ return arm_copy_unmodified (gdbarch, insn, "neon dataproc", dsc);
+ else if ((op1 & 0x71) == 0x40)
+ return arm_copy_unmodified (gdbarch, insn, "neon elt/struct load/store",
+ dsc);
+ else if ((op1 & 0x77) == 0x41)
+ return arm_copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc);
+ else if ((op1 & 0x77) == 0x45)
+ return arm_copy_preload (gdbarch, insn, regs, dsc); /* pli. */
+ else if ((op1 & 0x77) == 0x51)
+ {
+ if (rn != 0xf)
+ return arm_copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */
else
- /* {ldr,str}[b]<cond> rt, [rn, rm], etc.
- ->
- {ldr,str}[b]<cond> r0, [r2, r3]. */
- dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003;
+ return arm_copy_unpred (gdbarch, insn, dsc);
}
+ else if ((op1 & 0x77) == 0x55)
+ return arm_copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */
+ else if (op1 == 0x57)
+ switch (op2)
+ {
+ case 0x1: return arm_copy_unmodified (gdbarch, insn, "clrex", dsc);
+ case 0x4: return arm_copy_unmodified (gdbarch, insn, "dsb", dsc);
+ case 0x5: return arm_copy_unmodified (gdbarch, insn, "dmb", dsc);
+ case 0x6: return arm_copy_unmodified (gdbarch, insn, "isb", dsc);
+ default: return arm_copy_unpred (gdbarch, insn, dsc);
+ }
+ else if ((op1 & 0x63) == 0x43)
+ return arm_copy_unpred (gdbarch, insn, dsc);
+ else if ((op2 & 0x1) == 0x0)
+ switch (op1 & ~0x80)
+ {
+ case 0x61:
+ return arm_copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc);
+ case 0x65:
+ return arm_copy_preload_reg (gdbarch, insn, regs, dsc); /* pli reg. */
+ case 0x71: case 0x75:
+ /* pld/pldw reg. */
+ return arm_copy_preload_reg (gdbarch, insn, regs, dsc);
+ case 0x63: case 0x67: case 0x73: case 0x77:
+ return arm_copy_unpred (gdbarch, insn, dsc);
+ default:
+ return arm_copy_undef (gdbarch, insn, dsc);
+ }
else
+ return arm_copy_undef (gdbarch, insn, dsc); /* Probably unreachable. */
+}
+
+static int
+arm_decode_unconditional (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ if (bit (insn, 27) == 0)
+ return arm_decode_misc_memhint_neon (gdbarch, insn, regs, dsc);
+ /* Switch on bits: 0bxxxxx321xxx0xxxxxxxxxxxxxxxxxxxx. */
+ else switch (((insn & 0x7000000) >> 23) | ((insn & 0x100000) >> 20))
{
- /* We need to use r4 as scratch. Make sure it's restored afterwards. */
- dsc->u.ldst.restore_r4 = 1;
+ case 0x0: case 0x2:
+ return arm_copy_unmodified (gdbarch, insn, "srs", dsc);
- dsc->modinsn[0] = 0xe58ff014; /* str pc, [pc, #20]. */
- dsc->modinsn[1] = 0xe59f4010; /* ldr r4, [pc, #16]. */
- dsc->modinsn[2] = 0xe044400f; /* sub r4, r4, pc. */
- dsc->modinsn[3] = 0xe2844008; /* add r4, r4, #8. */
- dsc->modinsn[4] = 0xe0800004; /* add r0, r0, r4. */
+ case 0x1: case 0x3:
+ return arm_copy_unmodified (gdbarch, insn, "rfe", dsc);
- /* As above. */
- if (immed)
- dsc->modinsn[5] = (insn & 0xfff00fff) | 0x20000;
- else
- dsc->modinsn[5] = (insn & 0xfff00ff0) | 0x20003;
+ case 0x4: case 0x5: case 0x6: case 0x7:
+ return arm_copy_b_bl_blx (gdbarch, insn, regs, dsc);
- dsc->modinsn[6] = 0x0; /* breakpoint location. */
- dsc->modinsn[7] = 0x0; /* scratch space. */
+ case 0x8:
+ switch ((insn & 0xe00000) >> 21)
+ {
+ case 0x1: case 0x3: case 0x4: case 0x5: case 0x6: case 0x7:
+ /* stc/stc2. */
+ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc);
- dsc->numinsns = 6;
- }
+ case 0x2:
+ return arm_copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc);
- dsc->cleanup = load ? &cleanup_load : &cleanup_store;
+ default:
+ return arm_copy_undef (gdbarch, insn, dsc);
+ }
- return 0;
-}
+ case 0x9:
+ {
+ int rn_f = (bits (insn, 16, 19) == 0xf);
+ switch ((insn & 0xe00000) >> 21)
+ {
+ case 0x1: case 0x3:
+ /* ldc/ldc2 imm (undefined for rn == pc). */
+ return rn_f ? arm_copy_undef (gdbarch, insn, dsc)
+ : arm_copy_copro_load_store (gdbarch, insn, regs, dsc);
-/* Cleanup LDM instructions with fully-populated register list. This is an
- unfortunate corner case: it's impossible to implement correctly by modifying
- the instruction. The issue is as follows: we have an instruction,
+ case 0x2:
+ return arm_copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc);
- ldm rN, {r0-r15}
+ case 0x4: case 0x5: case 0x6: case 0x7:
+ /* ldc/ldc2 lit (undefined for rn != pc). */
+ return rn_f ? arm_copy_copro_load_store (gdbarch, insn, regs, dsc)
+ : arm_copy_undef (gdbarch, insn, dsc);
- which we must rewrite to avoid loading PC. A possible solution would be to
- do the load in two halves, something like (with suitable cleanup
- afterwards):
+ default:
+ return arm_copy_undef (gdbarch, insn, dsc);
+ }
+ }
- mov r8, rN
- ldm[id][ab] r8!, {r0-r7}
- str r7, <temp>
- ldm[id][ab] r8, {r7-r14}
- <bkpt>
+ case 0xa:
+ return arm_copy_unmodified (gdbarch, insn, "stc/stc2", dsc);
- but at present there's no suitable place for <temp>, since the scratch space
- is overwritten before the cleanup routine is called. For now, we simply
- emulate the instruction. */
+ case 0xb:
+ if (bits (insn, 16, 19) == 0xf)
+ /* ldc/ldc2 lit. */
+ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc);
+ else
+ return arm_copy_undef (gdbarch, insn, dsc);
-static void
-cleanup_block_load_all (struct gdbarch *gdbarch, struct regcache *regs,
- struct displaced_step_closure *dsc)
-{
- ULONGEST from = dsc->insn_addr;
- int inc = dsc->u.block.increment;
- int bump_before = dsc->u.block.before ? (inc ? 4 : -4) : 0;
- int bump_after = dsc->u.block.before ? 0 : (inc ? 4 : -4);
- uint32_t regmask = dsc->u.block.regmask;
- int regno = inc ? 0 : 15;
- CORE_ADDR xfer_addr = dsc->u.block.xfer_addr;
- int exception_return = dsc->u.block.load && dsc->u.block.user
- && (regmask & 0x8000) != 0;
- uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
- int do_transfer = condition_true (dsc->u.block.cond, status);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ case 0xc:
+ if (bit (insn, 4))
+ return arm_copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc);
+ else
+ return arm_copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
- if (!do_transfer)
- return;
+ case 0xd:
+ if (bit (insn, 4))
+ return arm_copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc);
+ else
+ return arm_copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
- /* If the instruction is ldm rN, {...pc}^, I don't think there's anything
- sensible we can do here. Complain loudly. */
- if (exception_return)
- error (_("Cannot single-step exception return"));
+ default:
+ return arm_copy_undef (gdbarch, insn, dsc);
+ }
+}
- /* We don't handle any stores here for now. */
- gdb_assert (dsc->u.block.load != 0);
+/* Decode miscellaneous instructions in dp/misc encoding space. */
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: emulating block transfer: "
- "%s %s %s\n", dsc->u.block.load ? "ldm" : "stm",
- dsc->u.block.increment ? "inc" : "dec",
- dsc->u.block.before ? "before" : "after");
+static int
+arm_decode_miscellaneous (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int op2 = bits (insn, 4, 6);
+ unsigned int op = bits (insn, 21, 22);
+ unsigned int op1 = bits (insn, 16, 19);
- while (regmask)
+ switch (op2)
{
- uint32_t memword;
+ case 0x0:
+ return arm_copy_unmodified (gdbarch, insn, "mrs/msr", dsc);
- if (inc)
- while (regno <= 15 && (regmask & (1 << regno)) == 0)
- regno++;
+ case 0x1:
+ if (op == 0x1) /* bx. */
+ return arm_copy_bx_blx_reg (gdbarch, insn, regs, dsc);
+ else if (op == 0x3)
+ return arm_copy_unmodified (gdbarch, insn, "clz", dsc);
else
- while (regno >= 0 && (regmask & (1 << regno)) == 0)
- regno--;
+ return arm_copy_undef (gdbarch, insn, dsc);
- xfer_addr += bump_before;
+ case 0x2:
+ if (op == 0x1)
+ /* Not really supported. */
+ return arm_copy_unmodified (gdbarch, insn, "bxj", dsc);
+ else
+ return arm_copy_undef (gdbarch, insn, dsc);
- memword = read_memory_unsigned_integer (xfer_addr, 4, byte_order);
- displaced_write_reg (regs, dsc, regno, memword, LOAD_WRITE_PC);
+ case 0x3:
+ if (op == 0x1)
+ return arm_copy_bx_blx_reg (gdbarch, insn,
+ regs, dsc); /* blx register. */
+ else
+ return arm_copy_undef (gdbarch, insn, dsc);
- xfer_addr += bump_after;
+ case 0x5:
+ return arm_copy_unmodified (gdbarch, insn, "saturating add/sub", dsc);
- regmask &= ~(1 << regno);
- }
+ case 0x7:
+ if (op == 0x1)
+ return arm_copy_unmodified (gdbarch, insn, "bkpt", dsc);
+ else if (op == 0x3)
+ /* Not really supported. */
+ return arm_copy_unmodified (gdbarch, insn, "smc", dsc);
- if (dsc->u.block.writeback)
- displaced_write_reg (regs, dsc, dsc->u.block.rn, xfer_addr,
- CANNOT_WRITE_PC);
+ default:
+ return arm_copy_undef (gdbarch, insn, dsc);
+ }
}
-/* Clean up an STM which included the PC in the register list. */
-
-static void
-cleanup_block_store_pc (struct gdbarch *gdbarch, struct regcache *regs,
- struct displaced_step_closure *dsc)
+static int
+arm_decode_dp_misc (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- ULONGEST from = dsc->insn_addr;
- uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
- int store_executed = condition_true (dsc->u.block.cond, status);
- CORE_ADDR pc_stored_at, transferred_regs = bitcount (dsc->u.block.regmask);
- CORE_ADDR stm_insn_addr;
- uint32_t pc_val;
- long offset;
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ if (bit (insn, 25))
+ switch (bits (insn, 20, 24))
+ {
+ case 0x10:
+ return arm_copy_unmodified (gdbarch, insn, "movw", dsc);
- /* If condition code fails, there's nothing else to do. */
- if (!store_executed)
- return;
+ case 0x14:
+ return arm_copy_unmodified (gdbarch, insn, "movt", dsc);
- if (dsc->u.block.increment)
- {
- pc_stored_at = dsc->u.block.xfer_addr + 4 * transferred_regs;
+ case 0x12: case 0x16:
+ return arm_copy_unmodified (gdbarch, insn, "msr imm", dsc);
- if (dsc->u.block.before)
- pc_stored_at += 4;
- }
+ default:
+ return arm_copy_alu_imm (gdbarch, insn, regs, dsc);
+ }
else
{
- pc_stored_at = dsc->u.block.xfer_addr;
+ uint32_t op1 = bits (insn, 20, 24), op2 = bits (insn, 4, 7);
- if (dsc->u.block.before)
- pc_stored_at -= 4;
+ if ((op1 & 0x19) != 0x10 && (op2 & 0x1) == 0x0)
+ return arm_copy_alu_reg (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x19) != 0x10 && (op2 & 0x9) == 0x1)
+ return arm_copy_alu_shifted_reg (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x19) == 0x10 && (op2 & 0x8) == 0x0)
+ return arm_decode_miscellaneous (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x19) == 0x10 && (op2 & 0x9) == 0x8)
+ return arm_copy_unmodified (gdbarch, insn, "halfword mul/mla", dsc);
+ else if ((op1 & 0x10) == 0x00 && op2 == 0x9)
+ return arm_copy_unmodified (gdbarch, insn, "mul/mla", dsc);
+ else if ((op1 & 0x10) == 0x10 && op2 == 0x9)
+ return arm_copy_unmodified (gdbarch, insn, "synch", dsc);
+ else if (op2 == 0xb || (op2 & 0xd) == 0xd)
+ /* 2nd arg means "unpriveleged". */
+ return arm_copy_extra_ld_st (gdbarch, insn, (op1 & 0x12) == 0x02, regs,
+ dsc);
}
- pc_val = read_memory_unsigned_integer (pc_stored_at, 4, byte_order);
- stm_insn_addr = dsc->scratch_base;
- offset = pc_val - stm_insn_addr;
-
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: detected PC offset %.8lx for "
- "STM instruction\n", offset);
-
- /* Rewrite the stored PC to the proper value for the non-displaced original
- instruction. */
- write_memory_unsigned_integer (pc_stored_at, 4, byte_order,
- dsc->insn_addr + offset);
+ /* Should be unreachable. */
+ return 1;
}
-/* Clean up an LDM which includes the PC in the register list. We clumped all
- the registers in the transferred list into a contiguous range r0...rX (to
- avoid loading PC directly and losing control of the debugged program), so we
- must undo that here. */
-
-static void
-cleanup_block_load_pc (struct gdbarch *gdbarch,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
+static int
+arm_decode_ld_st_word_ubyte (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- ULONGEST from = dsc->insn_addr;
- uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
- int load_executed = condition_true (dsc->u.block.cond, status), i;
- unsigned int mask = dsc->u.block.regmask, write_reg = 15;
- unsigned int regs_loaded = bitcount (mask);
- unsigned int num_to_shuffle = regs_loaded, clobbered;
-
- /* The method employed here will fail if the register list is fully populated
- (we need to avoid loading PC directly). */
- gdb_assert (num_to_shuffle < 16);
+ int a = bit (insn, 25), b = bit (insn, 4);
+ uint32_t op1 = bits (insn, 20, 24);
+ int rn_f = bits (insn, 16, 19) == 0xf;
- if (!load_executed)
- return;
+ if ((!a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02)
+ || (a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02 && !b))
+ return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 4, 0);
+ else if ((!a && (op1 & 0x17) == 0x02)
+ || (a && (op1 & 0x17) == 0x02 && !b))
+ return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 4, 1);
+ else if ((!a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03)
+ || (a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03 && !b))
+ return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 4, 0);
+ else if ((!a && (op1 & 0x17) == 0x03)
+ || (a && (op1 & 0x17) == 0x03 && !b))
+ return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 4, 1);
+ else if ((!a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06)
+ || (a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06 && !b))
+ return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 0);
+ else if ((!a && (op1 & 0x17) == 0x06)
+ || (a && (op1 & 0x17) == 0x06 && !b))
+ return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 1);
+ else if ((!a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07)
+ || (a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07 && !b))
+ return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 0);
+ else if ((!a && (op1 & 0x17) == 0x07)
+ || (a && (op1 & 0x17) == 0x07 && !b))
+ return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 1);
- clobbered = (1 << num_to_shuffle) - 1;
+ /* Should be unreachable. */
+ return 1;
+}
- while (num_to_shuffle > 0)
+static int
+arm_decode_media (struct gdbarch *gdbarch, uint32_t insn,
+ struct displaced_step_closure *dsc)
+{
+ switch (bits (insn, 20, 24))
{
- if ((mask & (1 << write_reg)) != 0)
- {
- unsigned int read_reg = num_to_shuffle - 1;
+ case 0x00: case 0x01: case 0x02: case 0x03:
+ return arm_copy_unmodified (gdbarch, insn, "parallel add/sub signed", dsc);
- if (read_reg != write_reg)
- {
- ULONGEST rval = displaced_read_reg (regs, from, read_reg);
- displaced_write_reg (regs, dsc, write_reg, rval, LOAD_WRITE_PC);
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: move "
- "loaded register r%d to r%d\n"), read_reg,
- write_reg);
- }
- else if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: register "
- "r%d already in the right place\n"),
- write_reg);
+ case 0x04: case 0x05: case 0x06: case 0x07:
+ return arm_copy_unmodified (gdbarch, insn, "parallel add/sub unsigned", dsc);
- clobbered &= ~(1 << write_reg);
+ case 0x08: case 0x09: case 0x0a: case 0x0b:
+ case 0x0c: case 0x0d: case 0x0e: case 0x0f:
+ return arm_copy_unmodified (gdbarch, insn,
+ "decode/pack/unpack/saturate/reverse", dsc);
- num_to_shuffle--;
+ case 0x18:
+ if (bits (insn, 5, 7) == 0) /* op2. */
+ {
+ if (bits (insn, 12, 15) == 0xf)
+ return arm_copy_unmodified (gdbarch, insn, "usad8", dsc);
+ else
+ return arm_copy_unmodified (gdbarch, insn, "usada8", dsc);
}
+ else
+ return arm_copy_undef (gdbarch, insn, dsc);
- write_reg--;
- }
+ case 0x1a: case 0x1b:
+ if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */
+ return arm_copy_unmodified (gdbarch, insn, "sbfx", dsc);
+ else
+ return arm_copy_undef (gdbarch, insn, dsc);
- /* Restore any registers we scribbled over. */
- for (write_reg = 0; clobbered != 0; write_reg++)
- {
- if ((clobbered & (1 << write_reg)) != 0)
- {
- displaced_write_reg (regs, dsc, write_reg, dsc->tmp[write_reg],
- CANNOT_WRITE_PC);
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: restored "
- "clobbered register r%d\n"), write_reg);
- clobbered &= ~(1 << write_reg);
+ case 0x1c: case 0x1d:
+ if (bits (insn, 5, 6) == 0x0) /* op2[1:0]. */
+ {
+ if (bits (insn, 0, 3) == 0xf)
+ return arm_copy_unmodified (gdbarch, insn, "bfc", dsc);
+ else
+ return arm_copy_unmodified (gdbarch, insn, "bfi", dsc);
}
- }
-
- /* Perform register writeback manually. */
- if (dsc->u.block.writeback)
- {
- ULONGEST new_rn_val = dsc->u.block.xfer_addr;
-
- if (dsc->u.block.increment)
- new_rn_val += regs_loaded * 4;
else
- new_rn_val -= regs_loaded * 4;
+ return arm_copy_undef (gdbarch, insn, dsc);
- displaced_write_reg (regs, dsc, dsc->u.block.rn, new_rn_val,
- CANNOT_WRITE_PC);
+ case 0x1e: case 0x1f:
+ if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */
+ return arm_copy_unmodified (gdbarch, insn, "ubfx", dsc);
+ else
+ return arm_copy_undef (gdbarch, insn, dsc);
}
-}
-/* Handle ldm/stm, apart from some tricky cases which are unlikely to occur
- in user-level code (in particular exception return, ldm rn, {...pc}^). */
+ /* Should be unreachable. */
+ return 1;
+}
static int
-copy_block_xfer (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
- struct displaced_step_closure *dsc)
+arm_decode_b_bl_ldmstm (struct gdbarch *gdbarch, int32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- int load = bit (insn, 20);
- int user = bit (insn, 22);
- int increment = bit (insn, 23);
- int before = bit (insn, 24);
- int writeback = bit (insn, 21);
- int rn = bits (insn, 16, 19);
- CORE_ADDR from = dsc->insn_addr;
+ if (bit (insn, 25))
+ return arm_copy_b_bl_blx (gdbarch, insn, regs, dsc);
+ else
+ return arm_copy_block_xfer (gdbarch, insn, regs, dsc);
+}
- /* Block transfers which don't mention PC can be run directly
- out-of-line. */
- if (rn != 15 && (insn & 0x8000) == 0)
- return copy_unmodified (gdbarch, insn, "ldm/stm", dsc);
+static int
+arm_decode_ext_reg_ld_st (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int opcode = bits (insn, 20, 24);
- if (rn == 15)
+ switch (opcode)
{
- warning (_("displaced: Unpredictable LDM or STM with "
- "base register r15"));
- return copy_unmodified (gdbarch, insn, "unpredictable ldm/stm", dsc);
- }
+ case 0x04: case 0x05: /* VFP/Neon mrrc/mcrr. */
+ return arm_copy_unmodified (gdbarch, insn, "vfp/neon mrrc/mcrr", dsc);
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying block transfer insn "
- "%.8lx\n", (unsigned long) insn);
+ case 0x08: case 0x0a: case 0x0c: case 0x0e:
+ case 0x12: case 0x16:
+ return arm_copy_unmodified (gdbarch, insn, "vfp/neon vstm/vpush", dsc);
- dsc->u.block.xfer_addr = displaced_read_reg (regs, from, rn);
- dsc->u.block.rn = rn;
+ case 0x09: case 0x0b: case 0x0d: case 0x0f:
+ case 0x13: case 0x17:
+ return arm_copy_unmodified (gdbarch, insn, "vfp/neon vldm/vpop", dsc);
- dsc->u.block.load = load;
- dsc->u.block.user = user;
- dsc->u.block.increment = increment;
- dsc->u.block.before = before;
- dsc->u.block.writeback = writeback;
- dsc->u.block.cond = bits (insn, 28, 31);
+ case 0x10: case 0x14: case 0x18: case 0x1c: /* vstr. */
+ case 0x11: case 0x15: case 0x19: case 0x1d: /* vldr. */
+ /* Note: no writeback for these instructions. Bit 25 will always be
+ zero though (via caller), so the following works OK. */
+ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc);
+ }
- dsc->u.block.regmask = insn & 0xffff;
+ /* Should be unreachable. */
+ return 1;
+}
- if (load)
- {
- if ((insn & 0xffff) == 0xffff)
- {
- /* LDM with a fully-populated register list. This case is
- particularly tricky. Implement for now by fully emulating the
- instruction (which might not behave perfectly in all cases, but
- these instructions should be rare enough for that not to matter
- too much). */
- dsc->modinsn[0] = ARM_NOP;
+/* Decode shifted register instructions. */
- dsc->cleanup = &cleanup_block_load_all;
- }
- else
- {
- /* LDM of a list of registers which includes PC. Implement by
- rewriting the list of registers to be transferred into a
- contiguous chunk r0...rX before doing the transfer, then shuffling
- registers into the correct places in the cleanup routine. */
- unsigned int regmask = insn & 0xffff;
- unsigned int num_in_list = bitcount (regmask), new_regmask, bit = 1;
- unsigned int to = 0, from = 0, i, new_rn;
+static int
+thumb2_decode_dp_shift_reg (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ /* PC is only allowed to be used in instruction MOV. */
- for (i = 0; i < num_in_list; i++)
- dsc->tmp[i] = displaced_read_reg (regs, from, i);
+ unsigned int op = bits (insn1, 5, 8);
+ unsigned int rn = bits (insn1, 0, 3);
- /* Writeback makes things complicated. We need to avoid clobbering
- the base register with one of the registers in our modified
- register list, but just using a different register can't work in
- all cases, e.g.:
+ if (op == 0x2 && rn == 0xf) /* MOV */
+ return thumb2_copy_alu_imm (gdbarch, insn1, insn2, regs, dsc);
+ else
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "dp (shift reg)", dsc);
+}
- ldm r14!, {r0-r13,pc}
- which would need to be rewritten as:
+/* Decode extension register load/store. Exactly the same as
+ arm_decode_ext_reg_ld_st. */
- ldm rN!, {r0-r14}
+static int
+thumb2_decode_ext_reg_ld_st (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int opcode = bits (insn1, 4, 8);
- but that can't work, because there's no free register for N.
+ switch (opcode)
+ {
+ case 0x04: case 0x05:
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "vfp/neon vmov", dsc);
- Solve this by turning off the writeback bit, and emulating
- writeback manually in the cleanup routine. */
+ case 0x08: case 0x0c: /* 01x00 */
+ case 0x0a: case 0x0e: /* 01x10 */
+ case 0x12: case 0x16: /* 10x10 */
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "vfp/neon vstm/vpush", dsc);
- if (writeback)
- insn &= ~(1 << 21);
+ case 0x09: case 0x0d: /* 01x01 */
+ case 0x0b: case 0x0f: /* 01x11 */
+ case 0x13: case 0x17: /* 10x11 */
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "vfp/neon vldm/vpop", dsc);
- new_regmask = (1 << num_in_list) - 1;
+ case 0x10: case 0x14: case 0x18: case 0x1c: /* vstr. */
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "vstr", dsc);
+ case 0x11: case 0x15: case 0x19: case 0x1d: /* vldr. */
+ return thumb2_copy_copro_load_store (gdbarch, insn1, insn2, regs, dsc);
+ }
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, _("displaced: LDM r%d%s, "
- "{..., pc}: original reg list %.4x, modified "
- "list %.4x\n"), rn, writeback ? "!" : "",
- (int) insn & 0xffff, new_regmask);
+ /* Should be unreachable. */
+ return 1;
+}
- dsc->modinsn[0] = (insn & ~0xffff) | (new_regmask & 0xffff);
+static int
+arm_decode_svc_copro (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int op1 = bits (insn, 20, 25);
+ int op = bit (insn, 4);
+ unsigned int coproc = bits (insn, 8, 11);
+ unsigned int rn = bits (insn, 16, 19);
- dsc->cleanup = &cleanup_block_load_pc;
- }
+ if ((op1 & 0x20) == 0x00 && (op1 & 0x3a) != 0x00 && (coproc & 0xe) == 0xa)
+ return arm_decode_ext_reg_ld_st (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x21) == 0x00 && (op1 & 0x3a) != 0x00
+ && (coproc & 0xe) != 0xa)
+ /* stc/stc2. */
+ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x21) == 0x01 && (op1 & 0x3a) != 0x00
+ && (coproc & 0xe) != 0xa)
+ /* ldc/ldc2 imm/lit. */
+ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x3e) == 0x00)
+ return arm_copy_undef (gdbarch, insn, dsc);
+ else if ((op1 & 0x3e) == 0x04 && (coproc & 0xe) == 0xa)
+ return arm_copy_unmodified (gdbarch, insn, "neon 64bit xfer", dsc);
+ else if (op1 == 0x04 && (coproc & 0xe) != 0xa)
+ return arm_copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc);
+ else if (op1 == 0x05 && (coproc & 0xe) != 0xa)
+ return arm_copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc);
+ else if ((op1 & 0x30) == 0x20 && !op)
+ {
+ if ((coproc & 0xe) == 0xa)
+ return arm_copy_unmodified (gdbarch, insn, "vfp dataproc", dsc);
+ else
+ return arm_copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
}
+ else if ((op1 & 0x30) == 0x20 && op)
+ return arm_copy_unmodified (gdbarch, insn, "neon 8/16/32 bit xfer", dsc);
+ else if ((op1 & 0x31) == 0x20 && op && (coproc & 0xe) != 0xa)
+ return arm_copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc);
+ else if ((op1 & 0x31) == 0x21 && op && (coproc & 0xe) != 0xa)
+ return arm_copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc);
+ else if ((op1 & 0x30) == 0x30)
+ return arm_copy_svc (gdbarch, insn, regs, dsc);
else
- {
- /* STM of a list of registers which includes PC. Run the instruction
- as-is, but out of line: this will store the wrong value for the PC,
- so we must manually fix up the memory in the cleanup routine.
- Doing things this way has the advantage that we can auto-detect
- the offset of the PC write (which is architecture-dependent) in
- the cleanup routine. */
- dsc->modinsn[0] = insn;
+ return arm_copy_undef (gdbarch, insn, dsc); /* Possibly unreachable. */
+}
- dsc->cleanup = &cleanup_block_store_pc;
+static int
+thumb2_decode_svc_copro (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int coproc = bits (insn2, 8, 11);
+ unsigned int op1 = bits (insn1, 4, 9);
+ unsigned int bit_5_8 = bits (insn1, 5, 8);
+ unsigned int bit_9 = bit (insn1, 9);
+ unsigned int bit_4 = bit (insn1, 4);
+ unsigned int rn = bits (insn1, 0, 3);
+
+ if (bit_9 == 0)
+ {
+ if (bit_5_8 == 2)
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "neon 64bit xfer/mrrc/mrrc2/mcrr/mcrr2",
+ dsc);
+ else if (bit_5_8 == 0) /* UNDEFINED. */
+ return thumb_32bit_copy_undef (gdbarch, insn1, insn2, dsc);
+ else
+ {
+ /*coproc is 101x. SIMD/VFP, ext registers load/store. */
+ if ((coproc & 0xe) == 0xa)
+ return thumb2_decode_ext_reg_ld_st (gdbarch, insn1, insn2, regs,
+ dsc);
+ else /* coproc is not 101x. */
+ {
+ if (bit_4 == 0) /* STC/STC2. */
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "stc/stc2", dsc);
+ else /* LDC/LDC2 {literal, immeidate}. */
+ return thumb2_copy_copro_load_store (gdbarch, insn1, insn2,
+ regs, dsc);
+ }
+ }
}
+ else
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "coproc", dsc);
return 0;
}
-/* Cleanup/copy SVC (SWI) instructions. These two functions are overridden
- for Linux, where some SVC instructions must be treated specially. */
-
static void
-cleanup_svc (struct gdbarch *gdbarch, struct regcache *regs,
- struct displaced_step_closure *dsc)
+install_pc_relative (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc, int rd)
{
- CORE_ADDR from = dsc->insn_addr;
- CORE_ADDR resume_addr = from + 4;
+ /* ADR Rd, #imm
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: cleanup for svc, resume at "
- "%.8lx\n", (unsigned long) resume_addr);
+ Rewrite as:
- displaced_write_reg (regs, dsc, ARM_PC_REGNUM, resume_addr, BRANCH_WRITE_PC);
+ Preparation: Rd <- PC
+ Insn: ADD Rd, #imm
+ Cleanup: Null.
+ */
+
+ /* Rd <- PC */
+ int val = displaced_read_reg (regs, dsc, ARM_PC_REGNUM);
+ displaced_write_reg (regs, dsc, rd, val, CANNOT_WRITE_PC);
}
static int
-copy_svc (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,
- struct regcache *regs, struct displaced_step_closure *dsc)
+thumb_copy_pc_relative_16bit (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc,
+ int rd, unsigned int imm)
{
- CORE_ADDR from = dsc->insn_addr;
- /* Allow OS-specific code to override SVC handling. */
- if (dsc->u.svc.copy_svc_os)
- return dsc->u.svc.copy_svc_os (gdbarch, insn, to, regs, dsc);
+ /* Encoding T2: ADDS Rd, #imm */
+ dsc->modinsn[0] = (0x3000 | (rd << 8) | imm);
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying svc insn %.8lx\n",
- (unsigned long) insn);
+ install_pc_relative (gdbarch, regs, dsc, rd);
- /* Preparation: none.
- Insn: unmodified svc.
- Cleanup: pc <- insn_addr + 4. */
+ return 0;
+}
- dsc->modinsn[0] = insn;
+static int
+thumb_decode_pc_relative_16bit (struct gdbarch *gdbarch, uint16_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rd = bits (insn, 8, 10);
+ unsigned int imm8 = bits (insn, 0, 7);
- dsc->cleanup = &cleanup_svc;
- /* Pretend we wrote to the PC, so cleanup doesn't set PC to the next
- instruction. */
- dsc->wrote_to_pc = 1;
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying thumb adr r%d, #%d insn %.4x\n",
+ rd, imm8, insn);
- return 0;
+ return thumb_copy_pc_relative_16bit (gdbarch, regs, dsc, rd, imm8);
}
-/* Copy undefined instructions. */
-
static int
-copy_undef (struct gdbarch *gdbarch, uint32_t insn,
- struct displaced_step_closure *dsc)
-{
+thumb_copy_pc_relative_32bit (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rd = bits (insn2, 8, 11);
+ /* Since immediate has the same encoding in ADR ADD and SUB, so we simply
+ extract raw immediate encoding rather than computing immediate. When
+ generating ADD or SUB instruction, we can simply perform OR operation to
+ set immediate into ADD. */
+ unsigned int imm_3_8 = insn2 & 0x70ff;
+ unsigned int imm_i = insn1 & 0x0400; /* Clear all bits except bit 10. */
+
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog,
- "displaced: copying undefined insn %.8lx\n",
- (unsigned long) insn);
+ "displaced: copying thumb adr r%d, #%d:%d insn %.4x%.4x\n",
+ rd, imm_i, imm_3_8, insn1, insn2);
- dsc->modinsn[0] = insn;
+ if (bit (insn1, 7)) /* Encoding T2 */
+ {
+ /* Encoding T3: SUB Rd, Rd, #imm */
+ dsc->modinsn[0] = (0xf1a0 | rd | imm_i);
+ dsc->modinsn[1] = ((rd << 8) | imm_3_8);
+ }
+ else /* Encoding T3 */
+ {
+ /* Encoding T3: ADD Rd, Rd, #imm */
+ dsc->modinsn[0] = (0xf100 | rd | imm_i);
+ dsc->modinsn[1] = ((rd << 8) | imm_3_8);
+ }
+ dsc->numinsns = 2;
+
+ install_pc_relative (gdbarch, regs, dsc, rd);
return 0;
}
-/* Copy unpredictable instructions. */
-
static int
-copy_unpred (struct gdbarch *gdbarch, uint32_t insn,
- struct displaced_step_closure *dsc)
+thumb_copy_16bit_ldr_literal (struct gdbarch *gdbarch, unsigned short insn1,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
+ unsigned int rt = bits (insn1, 8, 10);
+ unsigned int pc;
+ int imm8 = (bits (insn1, 0, 7) << 2);
+ CORE_ADDR from = dsc->insn_addr;
+
+ /* LDR Rd, #imm8
+
+ Rwrite as:
+
+ Preparation: tmp0 <- R0, tmp2 <- R2, tmp3 <- R3, R2 <- PC, R3 <- #imm8;
+
+ Insn: LDR R0, [R2, R3];
+ Cleanup: R2 <- tmp2, R3 <- tmp3, Rd <- R0, R0 <- tmp0 */
+
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: copying unpredictable insn "
- "%.8lx\n", (unsigned long) insn);
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying thumb ldr r%d [pc #%d]\n"
+ , rt, imm8);
- dsc->modinsn[0] = insn;
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0);
+ dsc->tmp[2] = displaced_read_reg (regs, dsc, 2);
+ dsc->tmp[3] = displaced_read_reg (regs, dsc, 3);
+ pc = displaced_read_reg (regs, dsc, ARM_PC_REGNUM);
+ /* The assembler calculates the required value of the offset from the
+ Align(PC,4) value of this instruction to the label. */
+ pc = pc & 0xfffffffc;
+
+ displaced_write_reg (regs, dsc, 2, pc, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 3, imm8, CANNOT_WRITE_PC);
+
+ dsc->rd = rt;
+ dsc->u.ldst.xfersize = 4;
+ dsc->u.ldst.rn = 0;
+ dsc->u.ldst.immed = 0;
+ dsc->u.ldst.writeback = 0;
+ dsc->u.ldst.restore_r4 = 0;
+
+ dsc->modinsn[0] = 0x58d0; /* ldr r0, [r2, r3]*/
+
+ dsc->cleanup = &cleanup_load;
return 0;
}
-/* The decode_* functions are instruction decoding helpers. They mostly follow
- the presentation in the ARM ARM. */
+/* Copy Thumb cbnz/cbz insruction. */
static int
-decode_misc_memhint_neon (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
+thumb_copy_cbnz_cbz (struct gdbarch *gdbarch, uint16_t insn1,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- unsigned int op1 = bits (insn, 20, 26), op2 = bits (insn, 4, 7);
- unsigned int rn = bits (insn, 16, 19);
+ int non_zero = bit (insn1, 11);
+ unsigned int imm5 = (bit (insn1, 9) << 6) | (bits (insn1, 3, 7) << 1);
+ CORE_ADDR from = dsc->insn_addr;
+ int rn = bits (insn1, 0, 2);
+ int rn_val = displaced_read_reg (regs, dsc, rn);
- if (op1 == 0x10 && (op2 & 0x2) == 0x0 && (rn & 0xe) == 0x0)
- return copy_unmodified (gdbarch, insn, "cps", dsc);
- else if (op1 == 0x10 && op2 == 0x0 && (rn & 0xe) == 0x1)
- return copy_unmodified (gdbarch, insn, "setend", dsc);
- else if ((op1 & 0x60) == 0x20)
- return copy_unmodified (gdbarch, insn, "neon dataproc", dsc);
- else if ((op1 & 0x71) == 0x40)
- return copy_unmodified (gdbarch, insn, "neon elt/struct load/store", dsc);
- else if ((op1 & 0x77) == 0x41)
- return copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc);
- else if ((op1 & 0x77) == 0x45)
- return copy_preload (gdbarch, insn, regs, dsc); /* pli. */
- else if ((op1 & 0x77) == 0x51)
+ dsc->u.branch.cond = (rn_val && non_zero) || (!rn_val && !non_zero);
+ /* CBNZ and CBZ do not affect the condition flags. If condition is true,
+ set it INST_AL, so cleanup_branch will know branch is taken, otherwise,
+ condition is false, let it be, cleanup_branch will do nothing. */
+ if (dsc->u.branch.cond)
{
- if (rn != 0xf)
- return copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */
- else
- return copy_unpred (gdbarch, insn, dsc);
+ dsc->u.branch.cond = INST_AL;
+ dsc->u.branch.dest = from + 4 + imm5;
}
- else if ((op1 & 0x77) == 0x55)
- return copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */
- else if (op1 == 0x57)
- switch (op2)
- {
- case 0x1: return copy_unmodified (gdbarch, insn, "clrex", dsc);
- case 0x4: return copy_unmodified (gdbarch, insn, "dsb", dsc);
- case 0x5: return copy_unmodified (gdbarch, insn, "dmb", dsc);
- case 0x6: return copy_unmodified (gdbarch, insn, "isb", dsc);
- default: return copy_unpred (gdbarch, insn, dsc);
- }
- else if ((op1 & 0x63) == 0x43)
- return copy_unpred (gdbarch, insn, dsc);
- else if ((op2 & 0x1) == 0x0)
- switch (op1 & ~0x80)
- {
- case 0x61:
- return copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc);
- case 0x65:
- return copy_preload_reg (gdbarch, insn, regs, dsc); /* pli reg. */
- case 0x71: case 0x75:
- /* pld/pldw reg. */
- return copy_preload_reg (gdbarch, insn, regs, dsc);
- case 0x63: case 0x67: case 0x73: case 0x77:
- return copy_unpred (gdbarch, insn, dsc);
- default:
- return copy_undef (gdbarch, insn, dsc);
- }
else
- return copy_undef (gdbarch, insn, dsc); /* Probably unreachable. */
+ dsc->u.branch.dest = from + 2;
+
+ dsc->u.branch.link = 0;
+ dsc->u.branch.exchange = 0;
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying %s [r%d = 0x%x]"
+ " insn %.4x to %.8lx\n", non_zero ? "cbnz" : "cbz",
+ rn, rn_val, insn1, dsc->u.branch.dest);
+
+ dsc->modinsn[0] = THUMB_NOP;
+
+ dsc->cleanup = &cleanup_branch;
+ return 0;
}
+/* Copy Table Branch Byte/Halfword */
static int
-decode_unconditional (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
+thumb2_copy_table_branch (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- if (bit (insn, 27) == 0)
- return decode_misc_memhint_neon (gdbarch, insn, regs, dsc);
- /* Switch on bits: 0bxxxxx321xxx0xxxxxxxxxxxxxxxxxxxx. */
- else switch (((insn & 0x7000000) >> 23) | ((insn & 0x100000) >> 20))
- {
- case 0x0: case 0x2:
- return copy_unmodified (gdbarch, insn, "srs", dsc);
-
- case 0x1: case 0x3:
- return copy_unmodified (gdbarch, insn, "rfe", dsc);
-
- case 0x4: case 0x5: case 0x6: case 0x7:
- return copy_b_bl_blx (gdbarch, insn, regs, dsc);
+ ULONGEST rn_val, rm_val;
+ int is_tbh = bit (insn2, 4);
+ CORE_ADDR halfwords = 0;
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- case 0x8:
- switch ((insn & 0xe00000) >> 21)
- {
- case 0x1: case 0x3: case 0x4: case 0x5: case 0x6: case 0x7:
- /* stc/stc2. */
- return copy_copro_load_store (gdbarch, insn, regs, dsc);
+ rn_val = displaced_read_reg (regs, dsc, bits (insn1, 0, 3));
+ rm_val = displaced_read_reg (regs, dsc, bits (insn2, 0, 3));
- case 0x2:
- return copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc);
+ if (is_tbh)
+ {
+ gdb_byte buf[2];
- default:
- return copy_undef (gdbarch, insn, dsc);
- }
+ target_read_memory (rn_val + 2 * rm_val, buf, 2);
+ halfwords = extract_unsigned_integer (buf, 2, byte_order);
+ }
+ else
+ {
+ gdb_byte buf[1];
- case 0x9:
- {
- int rn_f = (bits (insn, 16, 19) == 0xf);
- switch ((insn & 0xe00000) >> 21)
- {
- case 0x1: case 0x3:
- /* ldc/ldc2 imm (undefined for rn == pc). */
- return rn_f ? copy_undef (gdbarch, insn, dsc)
- : copy_copro_load_store (gdbarch, insn, regs, dsc);
+ target_read_memory (rn_val + rm_val, buf, 1);
+ halfwords = extract_unsigned_integer (buf, 1, byte_order);
+ }
- case 0x2:
- return copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: %s base 0x%x offset 0x%x"
+ " offset 0x%x\n", is_tbh ? "tbh" : "tbb",
+ (unsigned int) rn_val, (unsigned int) rm_val,
+ (unsigned int) halfwords);
- case 0x4: case 0x5: case 0x6: case 0x7:
- /* ldc/ldc2 lit (undefined for rn != pc). */
- return rn_f ? copy_copro_load_store (gdbarch, insn, regs, dsc)
- : copy_undef (gdbarch, insn, dsc);
+ dsc->u.branch.cond = INST_AL;
+ dsc->u.branch.link = 0;
+ dsc->u.branch.exchange = 0;
+ dsc->u.branch.dest = dsc->insn_addr + 4 + 2 * halfwords;
- default:
- return copy_undef (gdbarch, insn, dsc);
- }
- }
+ dsc->cleanup = &cleanup_branch;
- case 0xa:
- return copy_unmodified (gdbarch, insn, "stc/stc2", dsc);
+ return 0;
+}
- case 0xb:
- if (bits (insn, 16, 19) == 0xf)
- /* ldc/ldc2 lit. */
- return copy_copro_load_store (gdbarch, insn, regs, dsc);
- else
- return copy_undef (gdbarch, insn, dsc);
+static void
+cleanup_pop_pc_16bit_all (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ /* PC <- r7 */
+ int val = displaced_read_reg (regs, dsc, 7);
+ displaced_write_reg (regs, dsc, ARM_PC_REGNUM, val, BX_WRITE_PC);
- case 0xc:
- if (bit (insn, 4))
- return copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc);
- else
- return copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
+ /* r7 <- r8 */
+ val = displaced_read_reg (regs, dsc, 8);
+ displaced_write_reg (regs, dsc, 7, val, CANNOT_WRITE_PC);
- case 0xd:
- if (bit (insn, 4))
- return copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc);
- else
- return copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
+ /* r8 <- tmp[0] */
+ displaced_write_reg (regs, dsc, 8, dsc->tmp[0], CANNOT_WRITE_PC);
- default:
- return copy_undef (gdbarch, insn, dsc);
- }
}
-/* Decode miscellaneous instructions in dp/misc encoding space. */
-
static int
-decode_miscellaneous (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
+thumb_copy_pop_pc_16bit (struct gdbarch *gdbarch, unsigned short insn1,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- unsigned int op2 = bits (insn, 4, 6);
- unsigned int op = bits (insn, 21, 22);
- unsigned int op1 = bits (insn, 16, 19);
+ dsc->u.block.regmask = insn1 & 0x00ff;
- switch (op2)
- {
- case 0x0:
- return copy_unmodified (gdbarch, insn, "mrs/msr", dsc);
+ /* Rewrite instruction: POP {rX, rY, ...,rZ, PC}
+ to :
- case 0x1:
- if (op == 0x1) /* bx. */
- return copy_bx_blx_reg (gdbarch, insn, regs, dsc);
- else if (op == 0x3)
- return copy_unmodified (gdbarch, insn, "clz", dsc);
- else
- return copy_undef (gdbarch, insn, dsc);
+ (1) register list is full, that is, r0-r7 are used.
+ Prepare: tmp[0] <- r8
- case 0x2:
- if (op == 0x1)
- /* Not really supported. */
- return copy_unmodified (gdbarch, insn, "bxj", dsc);
- else
- return copy_undef (gdbarch, insn, dsc);
+ POP {r0, r1, ...., r6, r7}; remove PC from reglist
+ MOV r8, r7; Move value of r7 to r8;
+ POP {r7}; Store PC value into r7.
- case 0x3:
- if (op == 0x1)
- return copy_bx_blx_reg (gdbarch, insn,
- regs, dsc); /* blx register. */
- else
- return copy_undef (gdbarch, insn, dsc);
+ Cleanup: PC <- r7, r7 <- r8, r8 <-tmp[0]
- case 0x5:
- return copy_unmodified (gdbarch, insn, "saturating add/sub", dsc);
+ (2) register list is not full, supposing there are N registers in
+ register list (except PC, 0 <= N <= 7).
+ Prepare: for each i, 0 - N, tmp[i] <- ri.
- case 0x7:
- if (op == 0x1)
- return copy_unmodified (gdbarch, insn, "bkpt", dsc);
- else if (op == 0x3)
- /* Not really supported. */
- return copy_unmodified (gdbarch, insn, "smc", dsc);
+ POP {r0, r1, ...., rN};
- default:
- return copy_undef (gdbarch, insn, dsc);
+ Cleanup: Set registers in original reglist from r0 - rN. Restore r0 - rN
+ from tmp[] properly.
+ */
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: copying thumb pop {%.8x, pc} insn %.4x\n",
+ dsc->u.block.regmask, insn1);
+
+ if (dsc->u.block.regmask == 0xff)
+ {
+ dsc->tmp[0] = displaced_read_reg (regs, dsc, 8);
+
+ dsc->modinsn[0] = (insn1 & 0xfeff); /* POP {r0,r1,...,r6, r7} */
+ dsc->modinsn[1] = 0x46b8; /* MOV r8, r7 */
+ dsc->modinsn[2] = 0xbc80; /* POP {r7} */
+
+ dsc->numinsns = 3;
+ dsc->cleanup = &cleanup_pop_pc_16bit_all;
}
-}
+ else
+ {
+ unsigned int num_in_list = bitcount (dsc->u.block.regmask);
+ unsigned int new_regmask, bit = 1;
+ unsigned int to = 0, from = 0, i, new_rn;
-static int
-decode_dp_misc (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
- struct displaced_step_closure *dsc)
-{
- if (bit (insn, 25))
- switch (bits (insn, 20, 24))
- {
- case 0x10:
- return copy_unmodified (gdbarch, insn, "movw", dsc);
+ for (i = 0; i < num_in_list + 1; i++)
+ dsc->tmp[i] = displaced_read_reg (regs, dsc, i);
+
+ new_regmask = (1 << (num_in_list + 1)) - 1;
- case 0x14:
- return copy_unmodified (gdbarch, insn, "movt", dsc);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: POP "
+ "{..., pc}: original reg list %.4x,"
+ " modified list %.4x\n"),
+ (int) dsc->u.block.regmask, new_regmask);
- case 0x12: case 0x16:
- return copy_unmodified (gdbarch, insn, "msr imm", dsc);
+ dsc->u.block.regmask |= 0x8000;
+ dsc->u.block.writeback = 0;
+ dsc->u.block.cond = INST_AL;
- default:
- return copy_alu_imm (gdbarch, insn, regs, dsc);
- }
- else
- {
- uint32_t op1 = bits (insn, 20, 24), op2 = bits (insn, 4, 7);
+ dsc->modinsn[0] = (insn1 & ~0x1ff) | (new_regmask & 0xff);
- if ((op1 & 0x19) != 0x10 && (op2 & 0x1) == 0x0)
- return copy_alu_reg (gdbarch, insn, regs, dsc);
- else if ((op1 & 0x19) != 0x10 && (op2 & 0x9) == 0x1)
- return copy_alu_shifted_reg (gdbarch, insn, regs, dsc);
- else if ((op1 & 0x19) == 0x10 && (op2 & 0x8) == 0x0)
- return decode_miscellaneous (gdbarch, insn, regs, dsc);
- else if ((op1 & 0x19) == 0x10 && (op2 & 0x9) == 0x8)
- return copy_unmodified (gdbarch, insn, "halfword mul/mla", dsc);
- else if ((op1 & 0x10) == 0x00 && op2 == 0x9)
- return copy_unmodified (gdbarch, insn, "mul/mla", dsc);
- else if ((op1 & 0x10) == 0x10 && op2 == 0x9)
- return copy_unmodified (gdbarch, insn, "synch", dsc);
- else if (op2 == 0xb || (op2 & 0xd) == 0xd)
- /* 2nd arg means "unpriveleged". */
- return copy_extra_ld_st (gdbarch, insn, (op1 & 0x12) == 0x02, regs,
- dsc);
+ dsc->cleanup = &cleanup_block_load_pc;
}
- /* Should be unreachable. */
- return 1;
+ return 0;
}
-static int
-decode_ld_st_word_ubyte (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
+static void
+thumb_process_displaced_16bit_insn (struct gdbarch *gdbarch, uint16_t insn1,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- int a = bit (insn, 25), b = bit (insn, 4);
- uint32_t op1 = bits (insn, 20, 24);
- int rn_f = bits (insn, 16, 19) == 0xf;
+ unsigned short op_bit_12_15 = bits (insn1, 12, 15);
+ unsigned short op_bit_10_11 = bits (insn1, 10, 11);
+ int err = 0;
- if ((!a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02)
- || (a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02 && !b))
- return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 0, 0);
- else if ((!a && (op1 & 0x17) == 0x02)
- || (a && (op1 & 0x17) == 0x02 && !b))
- return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 0, 1);
- else if ((!a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03)
- || (a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03 && !b))
- return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 0, 0);
- else if ((!a && (op1 & 0x17) == 0x03)
- || (a && (op1 & 0x17) == 0x03 && !b))
- return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 0, 1);
- else if ((!a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06)
- || (a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06 && !b))
- return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 0);
- else if ((!a && (op1 & 0x17) == 0x06)
- || (a && (op1 & 0x17) == 0x06 && !b))
- return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 1);
- else if ((!a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07)
- || (a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07 && !b))
- return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 0);
- else if ((!a && (op1 & 0x17) == 0x07)
- || (a && (op1 & 0x17) == 0x07 && !b))
- return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 1);
+ /* 16-bit thumb instructions. */
+ switch (op_bit_12_15)
+ {
+ /* Shift (imme), add, subtract, move and compare. */
+ case 0: case 1: case 2: case 3:
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1,
+ "shift/add/sub/mov/cmp",
+ dsc);
+ break;
+ case 4:
+ switch (op_bit_10_11)
+ {
+ case 0: /* Data-processing */
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1,
+ "data-processing",
+ dsc);
+ break;
+ case 1: /* Special data instructions and branch and exchange. */
+ {
+ unsigned short op = bits (insn1, 7, 9);
+ if (op == 6 || op == 7) /* BX or BLX */
+ err = thumb_copy_bx_blx_reg (gdbarch, insn1, regs, dsc);
+ else if (bits (insn1, 6, 7) != 0) /* ADD/MOV/CMP high registers. */
+ err = thumb_copy_alu_reg (gdbarch, insn1, regs, dsc);
+ else
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "special data",
+ dsc);
+ }
+ break;
+ default: /* LDR (literal) */
+ err = thumb_copy_16bit_ldr_literal (gdbarch, insn1, regs, dsc);
+ }
+ break;
+ case 5: case 6: case 7: case 8: case 9: /* Load/Store single data item */
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "ldr/str", dsc);
+ break;
+ case 10:
+ if (op_bit_10_11 < 2) /* Generate PC-relative address */
+ err = thumb_decode_pc_relative_16bit (gdbarch, insn1, regs, dsc);
+ else /* Generate SP-relative address */
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "sp-relative", dsc);
+ break;
+ case 11: /* Misc 16-bit instructions */
+ {
+ switch (bits (insn1, 8, 11))
+ {
+ case 1: case 3: case 9: case 11: /* CBNZ, CBZ */
+ err = thumb_copy_cbnz_cbz (gdbarch, insn1, regs, dsc);
+ break;
+ case 12: case 13: /* POP */
+ if (bit (insn1, 8)) /* PC is in register list. */
+ err = thumb_copy_pop_pc_16bit (gdbarch, insn1, regs, dsc);
+ else
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "pop", dsc);
+ break;
+ case 15: /* If-Then, and hints */
+ if (bits (insn1, 0, 3))
+ /* If-Then makes up to four following instructions conditional.
+ IT instruction itself is not conditional, so handle it as a
+ common unmodified instruction. */
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "If-Then",
+ dsc);
+ else
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "hints", dsc);
+ break;
+ default:
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "misc", dsc);
+ }
+ }
+ break;
+ case 12:
+ if (op_bit_10_11 < 2) /* Store multiple registers */
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "stm", dsc);
+ else /* Load multiple registers */
+ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "ldm", dsc);
+ break;
+ case 13: /* Conditional branch and supervisor call */
+ if (bits (insn1, 9, 11) != 7) /* conditional branch */
+ err = thumb_copy_b (gdbarch, insn1, dsc);
+ else
+ err = thumb_copy_svc (gdbarch, insn1, regs, dsc);
+ break;
+ case 14: /* Unconditional branch */
+ err = thumb_copy_b (gdbarch, insn1, dsc);
+ break;
+ default:
+ err = 1;
+ }
- /* Should be unreachable. */
- return 1;
+ if (err)
+ internal_error (__FILE__, __LINE__,
+ _("thumb_process_displaced_16bit_insn: Instruction decode error"));
}
static int
-decode_media (struct gdbarch *gdbarch, uint32_t insn,
- struct displaced_step_closure *dsc)
-{
- switch (bits (insn, 20, 24))
- {
- case 0x00: case 0x01: case 0x02: case 0x03:
- return copy_unmodified (gdbarch, insn, "parallel add/sub signed", dsc);
-
- case 0x04: case 0x05: case 0x06: case 0x07:
- return copy_unmodified (gdbarch, insn, "parallel add/sub unsigned", dsc);
-
- case 0x08: case 0x09: case 0x0a: case 0x0b:
- case 0x0c: case 0x0d: case 0x0e: case 0x0f:
- return copy_unmodified (gdbarch, insn,
- "decode/pack/unpack/saturate/reverse", dsc);
+decode_thumb_32bit_ld_mem_hints (struct gdbarch *gdbarch,
+ uint16_t insn1, uint16_t insn2,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ int rt = bits (insn2, 12, 15);
+ int rn = bits (insn1, 0, 3);
+ int op1 = bits (insn1, 7, 8);
+ int err = 0;
- case 0x18:
- if (bits (insn, 5, 7) == 0) /* op2. */
- {
- if (bits (insn, 12, 15) == 0xf)
- return copy_unmodified (gdbarch, insn, "usad8", dsc);
+ switch (bits (insn1, 5, 6))
+ {
+ case 0: /* Load byte and memory hints */
+ if (rt == 0xf) /* PLD/PLI */
+ {
+ if (rn == 0xf)
+ /* PLD literal or Encoding T3 of PLI(immediate, literal). */
+ return thumb2_copy_preload (gdbarch, insn1, insn2, regs, dsc);
else
- return copy_unmodified (gdbarch, insn, "usada8", dsc);
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "pli/pld", dsc);
}
else
- return copy_undef (gdbarch, insn, dsc);
-
- case 0x1a: case 0x1b:
- if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */
- return copy_unmodified (gdbarch, insn, "sbfx", dsc);
- else
- return copy_undef (gdbarch, insn, dsc);
-
- case 0x1c: case 0x1d:
- if (bits (insn, 5, 6) == 0x0) /* op2[1:0]. */
- {
- if (bits (insn, 0, 3) == 0xf)
- return copy_unmodified (gdbarch, insn, "bfc", dsc);
+ {
+ if (rn == 0xf) /* LDRB/LDRSB (literal) */
+ return thumb2_copy_load_literal (gdbarch, insn1, insn2, regs, dsc,
+ 1);
else
- return copy_unmodified (gdbarch, insn, "bfi", dsc);
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "ldrb{reg, immediate}/ldrbt",
+ dsc);
}
- else
- return copy_undef (gdbarch, insn, dsc);
- case 0x1e: case 0x1f:
- if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */
- return copy_unmodified (gdbarch, insn, "ubfx", dsc);
+ break;
+ case 1: /* Load halfword and memory hints. */
+ if (rt == 0xf) /* PLD{W} and Unalloc memory hint. */
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "pld/unalloc memhint", dsc);
else
- return copy_undef (gdbarch, insn, dsc);
+ {
+ if (rn == 0xf)
+ return thumb2_copy_load_literal (gdbarch, insn1, insn2, regs, dsc,
+ 2);
+ else
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "ldrh/ldrht", dsc);
+ }
+ break;
+ case 2: /* Load word */
+ {
+ int insn2_bit_8_11 = bits (insn2, 8, 11);
+
+ if (rn == 0xf)
+ return thumb2_copy_load_literal (gdbarch, insn1, insn2, regs, dsc, 4);
+ else if (op1 == 0x1) /* Encoding T3 */
+ return thumb2_copy_load_reg_imm (gdbarch, insn1, insn2, regs, dsc,
+ 0, 1);
+ else /* op1 == 0x0 */
+ {
+ if (insn2_bit_8_11 == 0xc || (insn2_bit_8_11 & 0x9) == 0x9)
+ /* LDR (immediate) */
+ return thumb2_copy_load_reg_imm (gdbarch, insn1, insn2, regs,
+ dsc, bit (insn2, 8), 1);
+ else if (insn2_bit_8_11 == 0xe) /* LDRT */
+ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "ldrt", dsc);
+ else
+ /* LDR (register) */
+ return thumb2_copy_load_reg_imm (gdbarch, insn1, insn2, regs,
+ dsc, 0, 0);
+ }
+ break;
+ }
+ default:
+ return thumb_32bit_copy_undef (gdbarch, insn1, insn2, dsc);
+ break;
}
-
- /* Should be unreachable. */
- return 1;
-}
-
-static int
-decode_b_bl_ldmstm (struct gdbarch *gdbarch, int32_t insn,
- struct regcache *regs, struct displaced_step_closure *dsc)
-{
- if (bit (insn, 25))
- return copy_b_bl_blx (gdbarch, insn, regs, dsc);
- else
- return copy_block_xfer (gdbarch, insn, regs, dsc);
+ return 0;
}
-static int
-decode_ext_reg_ld_st (struct gdbarch *gdbarch, uint32_t insn,
- struct regcache *regs,
- struct displaced_step_closure *dsc)
+static void
+thumb_process_displaced_32bit_insn (struct gdbarch *gdbarch, uint16_t insn1,
+ uint16_t insn2, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- unsigned int opcode = bits (insn, 20, 24);
+ int err = 0;
+ unsigned short op = bit (insn2, 15);
+ unsigned int op1 = bits (insn1, 11, 12);
- switch (opcode)
+ switch (op1)
{
- case 0x04: case 0x05: /* VFP/Neon mrrc/mcrr. */
- return copy_unmodified (gdbarch, insn, "vfp/neon mrrc/mcrr", dsc);
-
- case 0x08: case 0x0a: case 0x0c: case 0x0e:
- case 0x12: case 0x16:
- return copy_unmodified (gdbarch, insn, "vfp/neon vstm/vpush", dsc);
-
- case 0x09: case 0x0b: case 0x0d: case 0x0f:
- case 0x13: case 0x17:
- return copy_unmodified (gdbarch, insn, "vfp/neon vldm/vpop", dsc);
+ case 1:
+ {
+ switch (bits (insn1, 9, 10))
+ {
+ case 0:
+ if (bit (insn1, 6))
+ {
+ /* Load/store {dual, execlusive}, table branch. */
+ if (bits (insn1, 7, 8) == 1 && bits (insn1, 4, 5) == 1
+ && bits (insn2, 5, 7) == 0)
+ err = thumb2_copy_table_branch (gdbarch, insn1, insn2, regs,
+ dsc);
+ else
+ /* PC is not allowed to use in load/store {dual, exclusive}
+ instructions. */
+ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "load/store dual/ex", dsc);
+ }
+ else /* load/store multiple */
+ {
+ switch (bits (insn1, 7, 8))
+ {
+ case 0: case 3: /* SRS, RFE */
+ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "srs/rfe", dsc);
+ break;
+ case 1: case 2: /* LDM/STM/PUSH/POP */
+ err = thumb2_copy_block_xfer (gdbarch, insn1, insn2, regs, dsc);
+ break;
+ }
+ }
+ break;
- case 0x10: case 0x14: case 0x18: case 0x1c: /* vstr. */
- case 0x11: case 0x15: case 0x19: case 0x1d: /* vldr. */
- /* Note: no writeback for these instructions. Bit 25 will always be
- zero though (via caller), so the following works OK. */
- return copy_copro_load_store (gdbarch, insn, regs, dsc);
+ case 1:
+ /* Data-processing (shift register). */
+ err = thumb2_decode_dp_shift_reg (gdbarch, insn1, insn2, regs,
+ dsc);
+ break;
+ default: /* Coprocessor instructions. */
+ err = thumb2_decode_svc_copro (gdbarch, insn1, insn2, regs, dsc);
+ break;
+ }
+ break;
+ }
+ case 2: /* op1 = 2 */
+ if (op) /* Branch and misc control. */
+ {
+ if (bit (insn2, 14) /* BLX/BL */
+ || bit (insn2, 12) /* Unconditional branch */
+ || (bits (insn1, 7, 9) != 0x7)) /* Conditional branch */
+ err = thumb2_copy_b_bl_blx (gdbarch, insn1, insn2, regs, dsc);
+ else
+ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "misc ctrl", dsc);
+ }
+ else
+ {
+ if (bit (insn1, 9)) /* Data processing (plain binary imm). */
+ {
+ int op = bits (insn1, 4, 8);
+ int rn = bits (insn1, 0, 3);
+ if ((op == 0 || op == 0xa) && rn == 0xf)
+ err = thumb_copy_pc_relative_32bit (gdbarch, insn1, insn2,
+ regs, dsc);
+ else
+ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "dp/pb", dsc);
+ }
+ else /* Data processing (modified immeidate) */
+ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "dp/mi", dsc);
+ }
+ break;
+ case 3: /* op1 = 3 */
+ switch (bits (insn1, 9, 10))
+ {
+ case 0:
+ if (bit (insn1, 4))
+ err = decode_thumb_32bit_ld_mem_hints (gdbarch, insn1, insn2,
+ regs, dsc);
+ else /* NEON Load/Store and Store single data item */
+ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "neon elt/struct load/store",
+ dsc);
+ break;
+ case 1: /* op1 = 3, bits (9, 10) == 1 */
+ switch (bits (insn1, 7, 8))
+ {
+ case 0: case 1: /* Data processing (register) */
+ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "dp(reg)", dsc);
+ break;
+ case 2: /* Multiply and absolute difference */
+ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "mul/mua/diff", dsc);
+ break;
+ case 3: /* Long multiply and divide */
+ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2,
+ "lmul/lmua", dsc);
+ break;
+ }
+ break;
+ default: /* Coprocessor instructions */
+ err = thumb2_decode_svc_copro (gdbarch, insn1, insn2, regs, dsc);
+ break;
+ }
+ break;
+ default:
+ err = 1;
}
- /* Should be unreachable. */
- return 1;
+ if (err)
+ internal_error (__FILE__, __LINE__,
+ _("thumb_process_displaced_32bit_insn: Instruction decode error"));
+
}
-static int
-decode_svc_copro (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,
- struct regcache *regs, struct displaced_step_closure *dsc)
+static void
+thumb_process_displaced_insn (struct gdbarch *gdbarch, CORE_ADDR from,
+ CORE_ADDR to, struct regcache *regs,
+ struct displaced_step_closure *dsc)
{
- unsigned int op1 = bits (insn, 20, 25);
- int op = bit (insn, 4);
- unsigned int coproc = bits (insn, 8, 11);
- unsigned int rn = bits (insn, 16, 19);
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ uint16_t insn1
+ = read_memory_unsigned_integer (from, 2, byte_order_for_code);
- if ((op1 & 0x20) == 0x00 && (op1 & 0x3a) != 0x00 && (coproc & 0xe) == 0xa)
- return decode_ext_reg_ld_st (gdbarch, insn, regs, dsc);
- else if ((op1 & 0x21) == 0x00 && (op1 & 0x3a) != 0x00
- && (coproc & 0xe) != 0xa)
- /* stc/stc2. */
- return copy_copro_load_store (gdbarch, insn, regs, dsc);
- else if ((op1 & 0x21) == 0x01 && (op1 & 0x3a) != 0x00
- && (coproc & 0xe) != 0xa)
- /* ldc/ldc2 imm/lit. */
- return copy_copro_load_store (gdbarch, insn, regs, dsc);
- else if ((op1 & 0x3e) == 0x00)
- return copy_undef (gdbarch, insn, dsc);
- else if ((op1 & 0x3e) == 0x04 && (coproc & 0xe) == 0xa)
- return copy_unmodified (gdbarch, insn, "neon 64bit xfer", dsc);
- else if (op1 == 0x04 && (coproc & 0xe) != 0xa)
- return copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc);
- else if (op1 == 0x05 && (coproc & 0xe) != 0xa)
- return copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc);
- else if ((op1 & 0x30) == 0x20 && !op)
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: process thumb insn %.4x "
+ "at %.8lx\n", insn1, (unsigned long) from);
+
+ dsc->is_thumb = 1;
+ dsc->insn_size = thumb_insn_size (insn1);
+ if (thumb_insn_size (insn1) == 4)
{
- if ((coproc & 0xe) == 0xa)
- return copy_unmodified (gdbarch, insn, "vfp dataproc", dsc);
- else
- return copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
+ uint16_t insn2
+ = read_memory_unsigned_integer (from + 2, 2, byte_order_for_code);
+ thumb_process_displaced_32bit_insn (gdbarch, insn1, insn2, regs, dsc);
}
- else if ((op1 & 0x30) == 0x20 && op)
- return copy_unmodified (gdbarch, insn, "neon 8/16/32 bit xfer", dsc);
- else if ((op1 & 0x31) == 0x20 && op && (coproc & 0xe) != 0xa)
- return copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc);
- else if ((op1 & 0x31) == 0x21 && op && (coproc & 0xe) != 0xa)
- return copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc);
- else if ((op1 & 0x30) == 0x30)
- return copy_svc (gdbarch, insn, to, regs, dsc);
else
- return copy_undef (gdbarch, insn, dsc); /* Possibly unreachable. */
+ thumb_process_displaced_16bit_insn (gdbarch, insn1, regs, dsc);
}
void
-arm_process_displaced_insn (struct gdbarch *gdbarch, uint32_t insn,
- CORE_ADDR from, CORE_ADDR to,
- struct regcache *regs,
+arm_process_displaced_insn (struct gdbarch *gdbarch, CORE_ADDR from,
+ CORE_ADDR to, struct regcache *regs,
struct displaced_step_closure *dsc)
{
int err = 0;
-
- if (!displaced_in_arm_mode (regs))
- error (_("Displaced stepping is only supported in ARM mode"));
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ uint32_t insn;
/* Most displaced instructions use a 1-instruction scratch space, so set this
here and override below if/when necessary. */
dsc->cleanup = NULL;
dsc->wrote_to_pc = 0;
+ if (!displaced_in_arm_mode (regs))
+ return thumb_process_displaced_insn (gdbarch, from, to, regs, dsc);
+
+ dsc->is_thumb = 0;
+ dsc->insn_size = 4;
+ insn = read_memory_unsigned_integer (from, 4, byte_order_for_code);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx "
+ "at %.8lx\n", (unsigned long) insn,
+ (unsigned long) from);
+
if ((insn & 0xf0000000) == 0xf0000000)
- err = decode_unconditional (gdbarch, insn, regs, dsc);
+ err = arm_decode_unconditional (gdbarch, insn, regs, dsc);
else switch (((insn & 0x10) >> 4) | ((insn & 0xe000000) >> 24))
{
case 0x0: case 0x1: case 0x2: case 0x3:
- err = decode_dp_misc (gdbarch, insn, regs, dsc);
+ err = arm_decode_dp_misc (gdbarch, insn, regs, dsc);
break;
case 0x4: case 0x5: case 0x6:
- err = decode_ld_st_word_ubyte (gdbarch, insn, regs, dsc);
+ err = arm_decode_ld_st_word_ubyte (gdbarch, insn, regs, dsc);
break;
case 0x7:
- err = decode_media (gdbarch, insn, dsc);
+ err = arm_decode_media (gdbarch, insn, dsc);
break;
case 0x8: case 0x9: case 0xa: case 0xb:
- err = decode_b_bl_ldmstm (gdbarch, insn, regs, dsc);
+ err = arm_decode_b_bl_ldmstm (gdbarch, insn, regs, dsc);
break;
case 0xc: case 0xd: case 0xe: case 0xf:
- err = decode_svc_copro (gdbarch, insn, to, regs, dsc);
+ err = arm_decode_svc_copro (gdbarch, insn, to, regs, dsc);
break;
}
CORE_ADDR to, struct displaced_step_closure *dsc)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
- unsigned int i;
+ unsigned int i, len, offset;
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ int size = dsc->is_thumb? 2 : 4;
+ const unsigned char *bkp_insn;
+ offset = 0;
/* Poke modified instruction(s). */
for (i = 0; i < dsc->numinsns; i++)
{
if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: writing insn %.8lx at "
- "%.8lx\n", (unsigned long) dsc->modinsn[i],
- (unsigned long) to + i * 4);
- write_memory_unsigned_integer (to + i * 4, 4, byte_order_for_code,
+ {
+ fprintf_unfiltered (gdb_stdlog, "displaced: writing insn ");
+ if (size == 4)
+ fprintf_unfiltered (gdb_stdlog, "%.8lx",
+ dsc->modinsn[i]);
+ else if (size == 2)
+ fprintf_unfiltered (gdb_stdlog, "%.4x",
+ (unsigned short)dsc->modinsn[i]);
+
+ fprintf_unfiltered (gdb_stdlog, " at %.8lx\n",
+ (unsigned long) to + offset);
+
+ }
+ write_memory_unsigned_integer (to + offset, size,
+ byte_order_for_code,
dsc->modinsn[i]);
+ offset += size;
+ }
+
+ /* Choose the correct breakpoint instruction. */
+ if (dsc->is_thumb)
+ {
+ bkp_insn = tdep->thumb_breakpoint;
+ len = tdep->thumb_breakpoint_size;
+ }
+ else
+ {
+ bkp_insn = tdep->arm_breakpoint;
+ len = tdep->arm_breakpoint_size;
}
/* Put breakpoint afterwards. */
- write_memory (to + dsc->numinsns * 4, tdep->arm_breakpoint,
- tdep->arm_breakpoint_size);
+ write_memory (to + offset, bkp_insn, len);
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ",
{
struct displaced_step_closure *dsc
= xmalloc (sizeof (struct displaced_step_closure));
- enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- uint32_t insn = read_memory_unsigned_integer (from, 4, byte_order_for_code);
-
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx "
- "at %.8lx\n", (unsigned long) insn,
- (unsigned long) from);
-
- arm_process_displaced_insn (gdbarch, insn, from, to, regs, dsc);
+ arm_process_displaced_insn (gdbarch, from, to, regs, dsc);
arm_displaced_init_closure (gdbarch, from, to, dsc);
return dsc;
dsc->cleanup (gdbarch, regs, dsc);
if (!dsc->wrote_to_pc)
- regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, dsc->insn_addr + 4);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM,
+ dsc->insn_addr + dsc->insn_size);
+
}
#include "bfd-in2.h"
{
unsigned short inst1;
inst1 = extract_unsigned_integer (buf, 2, byte_order_for_code);
- if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
+ if (thumb_insn_size (inst1) == 4)
{
*lenptr = tdep->thumb2_breakpoint_size;
return tdep->thumb2_breakpoint;
|| TYPE_CODE (type) == TYPE_CODE_REF
|| TYPE_CODE (type) == TYPE_CODE_ENUM)
{
- /* If the the type is a plain integer, then the access is
- straight-forward. Otherwise we have to play around a bit more. */
+ /* If the type is a plain integer, then the access is
+ straight-forward. Otherwise we have to play around a bit
+ more. */
int len = TYPE_LENGTH (type);
int regno = ARM_A1_REGNUM;
ULONGEST tmp;
break;
default:
- internal_error
- (__FILE__, __LINE__,
- _("arm_store_return_value: Floating point model not supported"));
+ internal_error (__FILE__, __LINE__,
+ _("arm_store_return_value: Floating "
+ "point model not supported"));
break;
}
}
gdbarch_info_init (&info);
if (!gdbarch_update_p (info))
- internal_error (__FILE__, __LINE__, "could not update architecture");
+ internal_error (__FILE__, __LINE__, _("could not update architecture"));
}
static void
static void
arm_elf_make_msymbol_special(asymbol *sym, struct minimal_symbol *msym)
{
- /* Thumb symbols are of type STT_LOPROC, (synonymous with
- STT_ARM_TFUNC). */
- if (ELF_ST_TYPE (((elf_symbol_type *)sym)->internal_elf_sym.st_info)
- == STT_LOPROC)
+ if (ARM_SYM_BRANCH_TYPE (&((elf_symbol_type *)sym)->internal_elf_sym)
+ == ST_BRANCH_TO_THUMB)
MSYMBOL_SET_SPECIAL (msym);
}
ABI, even if a NEON unit is not present. REGNUM is the index of
the quad register, in [0, 15]. */
-static void
+static enum register_status
arm_neon_quad_read (struct gdbarch *gdbarch, struct regcache *regcache,
int regnum, gdb_byte *buf)
{
char name_buf[4];
gdb_byte reg_buf[8];
int offset, double_regnum;
+ enum register_status status;
sprintf (name_buf, "d%d", regnum << 1);
double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
else
offset = 0;
- regcache_raw_read (regcache, double_regnum, reg_buf);
+ status = regcache_raw_read (regcache, double_regnum, reg_buf);
+ if (status != REG_VALID)
+ return status;
memcpy (buf + offset, reg_buf, 8);
offset = 8 - offset;
- regcache_raw_read (regcache, double_regnum + 1, reg_buf);
+ status = regcache_raw_read (regcache, double_regnum + 1, reg_buf);
+ if (status != REG_VALID)
+ return status;
memcpy (buf + offset, reg_buf, 8);
+
+ return REG_VALID;
}
-static void
+static enum register_status
arm_pseudo_read (struct gdbarch *gdbarch, struct regcache *regcache,
int regnum, gdb_byte *buf)
{
if (gdbarch_tdep (gdbarch)->have_neon_pseudos && regnum >= 32 && regnum < 48)
/* Quad-precision register. */
- arm_neon_quad_read (gdbarch, regcache, regnum - 32, buf);
+ return arm_neon_quad_read (gdbarch, regcache, regnum - 32, buf);
else
{
+ enum register_status status;
+
/* Single-precision register. */
gdb_assert (regnum < 32);
double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
strlen (name_buf));
- regcache_raw_read (regcache, double_regnum, reg_buf);
- memcpy (buf, reg_buf + offset, 4);
+ status = regcache_raw_read (regcache, double_regnum, reg_buf);
+ if (status == REG_VALID)
+ memcpy (buf, reg_buf + offset, 4);
+ return status;
}
}
arm_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
struct reggroup *group)
{
- /* FPS register's type is INT, but belongs to float_group. */
+ /* FPS register's type is INT, but belongs to float_reggroup. Beside
+ this, FPS register belongs to save_regroup, restore_reggroup, and
+ all_reggroup, of course. */
if (regnum == ARM_FPS_REGNUM)
- return (group == float_reggroup);
+ return (group == float_reggroup
+ || group == save_reggroup
+ || group == restore_reggroup
+ || group == all_reggroup);
else
return default_register_reggroup_p (gdbarch, regnum, group);
}
if (!valid_p)
break;
}
+ if (!valid_p && i == 16)
+ valid_p = 1;
- if (!valid_p && i != 16)
+ /* Also require FPSCR. */
+ valid_p &= tdesc_numbered_register (feature, tdesc_data,
+ ARM_FPSCR_REGNUM, "fpscr");
+ if (!valid_p)
{
tdesc_data_cleanup (tdesc_data);
return NULL;
/* Add some default predicates. */
frame_unwind_append_unwinder (gdbarch, &arm_stub_unwind);
dwarf2_append_unwinders (gdbarch);
+ frame_unwind_append_unwinder (gdbarch, &arm_exidx_unwind);
frame_unwind_append_unwinder (gdbarch, &arm_prologue_unwind);
/* Now we have tuned the configuration, set a few final things,
if (tdep->arm_abi == ARM_ABI_AUTO)
tdep->arm_abi = ARM_ABI_APCS;
+ /* Watchpoints are not steppable. */
+ set_gdbarch_have_nonsteppable_watchpoint (gdbarch, 1);
+
/* We used to default to FPA for generic ARM, but almost nobody
uses that now, and we now provide a way for the user to force
the model. So default to the most useful variant. */
arm_objfile_data_key
= register_objfile_data_with_cleanup (NULL, arm_objfile_data_free);
+ /* Add ourselves to objfile event chain. */
+ observer_attach_new_objfile (arm_exidx_new_objfile);
+ arm_exidx_data_key
+ = register_objfile_data_with_cleanup (NULL, arm_exidx_data_free);
+
/* Register an ELF OS ABI sniffer for ARM binaries. */
gdbarch_register_osabi_sniffer (bfd_arch_arm,
bfd_target_elf_flavour,
/* Initialize the standard target descriptions. */
initialize_tdesc_arm_with_m ();
+ initialize_tdesc_arm_with_iwmmxt ();
+ initialize_tdesc_arm_with_vfpv2 ();
+ initialize_tdesc_arm_with_vfpv3 ();
+ initialize_tdesc_arm_with_neon ();
/* Get the number of possible sets of register names defined in opcodes. */
num_disassembly_options = get_arm_regname_num_options ();
projects / deliverable / binutils-gdb.git / blobdiff