#include "elf/m68hc11.h"
#include "elf-bfd.h"
+/* Macros for setting and testing a bit in a minimal symbol.
+ For 68HC11/68HC12 we have two flags that tell which return
+ type the function is using. This is used for prologue and frame
+ analysis to compute correct stack frame layout.
+
+ The MSB of the minimal symbol's "info" field is used for this purpose.
+ This field is already being used to store the symbol size, so the
+ assumption is that the symbol size cannot exceed 2^30.
+
+ MSYMBOL_SET_RTC Actually sets the "RTC" bit.
+ MSYMBOL_SET_RTI Actually sets the "RTI" bit.
+ MSYMBOL_IS_RTC Tests the "RTC" bit in a minimal symbol.
+ MSYMBOL_IS_RTI Tests the "RTC" bit in a minimal symbol.
+ MSYMBOL_SIZE Returns the size of the minimal symbol,
+ i.e. the "info" field with the "special" bit
+ masked out. */
+
+#define MSYMBOL_SET_RTC(msym) \
+ MSYMBOL_INFO (msym) = (char *) (((long) MSYMBOL_INFO (msym)) \
+ | 0x80000000)
+
+#define MSYMBOL_SET_RTI(msym) \
+ MSYMBOL_INFO (msym) = (char *) (((long) MSYMBOL_INFO (msym)) \
+ | 0x40000000)
+
+#define MSYMBOL_IS_RTC(msym) \
+ (((long) MSYMBOL_INFO (msym) & 0x80000000) != 0)
+
+#define MSYMBOL_IS_RTI(msym) \
+ (((long) MSYMBOL_INFO (msym) & 0x40000000) != 0)
+
+#define MSYMBOL_SIZE(msym) \
+ ((long) MSYMBOL_INFO (msym) & 0x3fffffff)
+
+enum insn_return_kind {
+ RETURN_RTS,
+ RETURN_RTC,
+ RETURN_RTI
+};
+
+
/* Register numbers of various important registers.
Note that some of these values are "real" register numbers,
and correspond to the general registers of the machine,
/* Description of instructions in the prologue. */
struct insn_sequence *prologue;
+ /* True if the page memory bank register is available
+ and must be used. */
+ int use_page_register;
+
/* ELF flags for ABI. */
int elf_flags;
};
#define M6811_TDEP gdbarch_tdep (current_gdbarch)
#define STACK_CORRECTION (M6811_TDEP->stack_correction)
+#define USE_PAGE_REGISTER (M6811_TDEP->use_page_register)
struct frame_extra_info
{
- int frame_reg;
CORE_ADDR return_pc;
- CORE_ADDR dummy;
int frameless;
int size;
+ enum insn_return_kind return_kind;
};
/* Table of registers for 68HC11. This includes the hard registers
static CORE_ADDR
m68hc11_frame_args_address (struct frame_info *frame)
{
- return frame->frame + frame->extra_info->size + STACK_CORRECTION + 2;
+ CORE_ADDR addr;
+
+ addr = frame->frame + frame->extra_info->size + STACK_CORRECTION + 2;
+ if (frame->extra_info->return_kind == RETURN_RTC)
+ addr += 1;
+ else if (frame->extra_info->return_kind == RETURN_RTI)
+ addr += 7;
+
+ return addr;
}
static CORE_ADDR
return 0;
}
+/* Return the instruction that the function at the PC is using. */
+static enum insn_return_kind
+m68hc11_get_return_insn (CORE_ADDR pc)
+{
+ struct minimal_symbol *sym;
+
+ /* A flag indicating that this is a STO_M68HC12_FAR or STO_M68HC12_INTERRUPT
+ function is stored by elfread.c in the high bit of the info field.
+ Use this to decide which instruction the function uses to return. */
+ sym = lookup_minimal_symbol_by_pc (pc);
+ if (sym == 0)
+ return RETURN_RTS;
+
+ if (MSYMBOL_IS_RTC (sym))
+ return RETURN_RTC;
+ else if (MSYMBOL_IS_RTI (sym))
+ return RETURN_RTI;
+ else
+ return RETURN_RTS;
+}
+
+
/* Analyze the function prologue to find some information
about the function:
- the PC of the first line (for m68hc11_skip_prologue)
{
CORE_ADDR pc;
CORE_ADDR addr;
-
+
if (fi->saved_regs == NULL)
frame_saved_regs_zalloc (fi);
else
memset (fi->saved_regs, 0, sizeof (fi->saved_regs));
pc = fi->pc;
+ fi->extra_info->return_kind = m68hc11_get_return_insn (pc);
m68hc11_guess_from_prologue (pc, fi->frame, &pc, &fi->extra_info->size,
fi->saved_regs);
addr = fi->frame + fi->extra_info->size + STACK_CORRECTION;
if (soft_regs[SOFT_FP_REGNUM].name)
fi->saved_regs[SOFT_FP_REGNUM] = addr - 2;
+
+ /* Take into account how the function was called/returns. */
+ if (fi->extra_info->return_kind == RETURN_RTC)
+ {
+ fi->saved_regs[HARD_PAGE_REGNUM] = addr;
+ addr++;
+ }
+ else if (fi->extra_info->return_kind == RETURN_RTI)
+ {
+ fi->saved_regs[HARD_CCR_REGNUM] = addr;
+ fi->saved_regs[HARD_D_REGNUM] = addr + 1;
+ fi->saved_regs[HARD_X_REGNUM] = addr + 3;
+ fi->saved_regs[HARD_Y_REGNUM] = addr + 5;
+ addr += 7;
+ }
fi->saved_regs[HARD_SP_REGNUM] = addr;
fi->saved_regs[HARD_PC_REGNUM] = fi->saved_regs[HARD_SP_REGNUM];
}
if (fromleaf)
{
+ fi->extra_info->return_kind = m68hc11_get_return_insn (fi->pc);
fi->extra_info->return_pc = m68hc11_saved_pc_after_call (fi);
}
else
{
- addr = fi->frame + fi->extra_info->size + STACK_CORRECTION;
+ addr = fi->saved_regs[HARD_PC_REGNUM];
addr = read_memory_unsigned_integer (addr, 2) & 0x0ffff;
+
+ /* Take into account the 68HC12 specific call (PC + page). */
+ if (fi->extra_info->return_kind == RETURN_RTC
+ && addr >= 0x08000 && addr < 0x0c000
+ && USE_PAGE_REGISTER)
+ {
+ CORE_ADDR page_addr = fi->saved_regs[HARD_PAGE_REGNUM];
+
+ unsigned page = read_memory_unsigned_integer (page_addr, 1);
+ addr -= 0x08000;
+ addr += ((page & 0x0ff) << 14);
+ addr += 0x1000000;
+ }
fi->extra_info->return_pc = addr;
-#if 0
- printf ("Pc@0x%04x, FR 0x%04x, size %d, read ret @0x%04x -> 0x%04x\n",
- fi->pc,
- fi->frame, fi->size,
- addr & 0x0ffff,
- fi->return_pc);
-#endif
}
}
ccr & M6811_V_BIT ? 'V' : '-',
ccr & M6811_C_BIT ? 'C' : '-');
- printf_filtered ("D=%04x IX=%04x IY=%04x\n",
+ printf_filtered ("D=%04x IX=%04x IY=%04x",
(int) read_register (HARD_D_REGNUM),
(int) read_register (HARD_X_REGNUM),
(int) read_register (HARD_Y_REGNUM));
+ if (USE_PAGE_REGISTER)
+ {
+ printf_filtered (" Page=%02x",
+ (int) read_register (HARD_PAGE_REGNUM));
+ }
+ printf_filtered ("\n");
+
nr = 0;
for (i = SOFT_D1_REGNUM; i < M68HC11_ALL_REGS; i++)
{
}
}
+/* Test whether the ELF symbol corresponds to a function using rtc or
+ rti to return. */
+
+static void
+m68hc11_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
+{
+ unsigned char flags;
+
+ flags = ((elf_symbol_type *)sym)->internal_elf_sym.st_other;
+ if (flags & STO_M68HC12_FAR)
+ MSYMBOL_SET_RTC (msym);
+ if (flags & STO_M68HC12_INTERRUPT)
+ MSYMBOL_SET_RTI (msym);
+}
+
static int
gdb_print_insn_m68hc11 (bfd_vma memaddr, disassemble_info *info)
{
{
case bfd_arch_m68hc11:
tdep->stack_correction = 1;
+ tdep->use_page_register = 0;
tdep->prologue = m6811_prologue;
break;
case bfd_arch_m68hc12:
tdep->stack_correction = 0;
+ tdep->use_page_register = elf_flags & E_M68HC12_BANKS;
tdep->prologue = m6812_prologue;
break;
set_gdbarch_stack_align (gdbarch, m68hc11_stack_align);
set_gdbarch_print_insn (gdbarch, gdb_print_insn_m68hc11);
+ /* Minsymbol frobbing. */
+ set_gdbarch_elf_make_msymbol_special (gdbarch,
+ m68hc11_elf_make_msymbol_special);
+
set_gdbarch_believe_pcc_promotion (gdbarch, 1);
return gdbarch;
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