--- /dev/null
+/* Target machine description for VxWorks on the 29k, for GDB, the GNU debugger.
+ Copyright 1994 Free Software Foundation, Inc.
+ Contributed by Cygnus Support.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "a29k/tm-a29k.h"
+
+#define GDBINIT_FILENAME ".vxgdbinit"
+
+#define DEFAULT_PROMPT "(vxgdb) "
+
+/* Number of registers in a ptrace_getregs call. */
+
+#define VX_NUM_REGS (NUM_REGS)
+
+/* Number of registers in a ptrace_getfpregs call. */
+
+/* #define VX_SIZE_FPREGS */
+
+/* This is almost certainly the wrong place for this: */
+#define LR2_REGNUM 34
+\f
+
+/* Vxworks has its own CALL_DUMMY since it manages breakpoints in the kernel */
+
+#undef CALL_DUMMY
+
+/* Replace the breakpoint instruction in the CALL_DUMMY with a nop.
+ For Vxworks, the breakpoint is set and deleted by calls to
+ CALL_DUMMY_BREAK_SET and CALL_DUMMY_BREAK_DELETE. */
+
+#if TARGET_BYTE_ORDER == HOST_BYTE_ORDER
+#define CALL_DUMMY {0x0400870f,\
+ 0x36008200|(MSP_HW_REGNUM), \
+ 0x15000040|(MSP_HW_REGNUM<<8)|(MSP_HW_REGNUM<<16), \
+ 0x03ff80ff, 0x02ff80ff, 0xc8008080, 0x70400101, 0x70400101}
+#else /* Byte order differs. */
+#define CALL_DUMMY {0x0f870004,\
+ 0x00820036|(MSP_HW_REGNUM << 24), \
+ 0x40000015|(MSP_HW_REGNUM<<8)|(MSP_HW_REGNUM<<16), \
+ 0xff80ff03, 0xff80ff02, 0x808000c8, 0x01014070, 0x01014070}
+#endif /* Byte order differs. */
+
+
+/* For the basic CALL_DUMMY definitions, see "tm-29k.h." We use the
+ same CALL_DUMMY code, but define FIX_CALL_DUMMY (and related macros)
+ locally to handle remote debugging of VxWorks targets. The difference
+ is in the setting and clearing of the breakpoint at the end of the
+ CALL_DUMMY code fragment; under VxWorks, we can't simply insert a
+ breakpoint instruction into the code, since that would interfere with
+ the breakpoint management mechanism on the target.
+ Note that CALL_DUMMY is a piece of code that is used to call any C function
+ thru VxGDB */
+
+/* The offset of the instruction within the CALL_DUMMY code where we
+ want the inferior to stop after the function call has completed.
+ call_function_by_hand () sets a breakpoint here (via CALL_DUMMY_BREAK_SET),
+ which POP_FRAME later deletes (via CALL_DUMMY_BREAK_DELETE). */
+
+#define CALL_DUMMY_STOP_OFFSET (7 * 4)
+
+/* The offset of the first instruction of the CALL_DUMMY code fragment
+ relative to the frame pointer for a dummy frame. This is equal to
+ the size of the CALL_DUMMY plus the arg_slop area size (see the diagram
+ in "tm-29k.h"). */
+/* PAD : the arg_slop area size doesn't appear to me to be useful since, the
+ call dummy code no longer modify the msp. See below. This must be checked. */
+
+#define CALL_DUMMY_OFFSET_IN_FRAME (CALL_DUMMY_LENGTH + 16 * 4)
+
+/* Insert the specified number of args and function address
+ into a CALL_DUMMY sequence stored at DUMMYNAME, replace the third
+ instruction (add msp, msp, 16*4) with a nop, and leave the final nop.
+ We can't keep using a CALL_DUMMY that modify the msp since, for VxWorks,
+ CALL_DUMMY is stored in the Memory Stack. Adding 16 words to the msp
+ would then make possible for the inferior to overwrite the CALL_DUMMY code,
+ thus creating a lot of trouble when exiting the inferior to come back in
+ a CALL_DUMMY code that no longer exists... Furthermore, ESF are also stored
+ from the msp in the memory stack. If msp is set higher than the dummy code,
+ an ESF may clobber this code. */
+
+#if TARGET_BYTE_ORDER == BIG_ENDIAN
+#define NOP_INSTR 0x70400101
+#else /* Target is little endian */
+#define NOP_INSTR 0x01014070
+#endif
+
+#undef FIX_CALL_DUMMY
+#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
+ { \
+ *(int *)((char *)dummyname + 8) = NOP_INSTR; \
+ STUFF_I16((char *)dummyname + CONST_INSN, fun); \
+ STUFF_I16((char *)dummyname + CONST_INSN + 4, fun >> 16); \
+ }
+
+/* For VxWorks, CALL_DUMMY must be stored in the stack of the task that is
+ being debugged and executed "in the context of" this task */
+
+#undef CALL_DUMMY_LOCATION
+#define CALL_DUMMY_LOCATION ON_STACK
+
+/* Set or delete a breakpoint at the location within a CALL_DUMMY code
+ fragment where we want the target program to stop after the function
+ call is complete. CALL_DUMMY_ADDR is the address of the first
+ instruction in the CALL_DUMMY. DUMMY_FRAME_ADDR is the value of the
+ frame pointer in the dummy frame.
+
+ NOTE: in the both of the following definitions, we take advantage of
+ knowledge of the implementation of the target breakpoint operation,
+ in that we pass a null pointer as the second argument. It seems
+ reasonable to assume that any target requiring the use of
+ CALL_DUMMY_BREAK_{SET,DELETE} will not store the breakpoint
+ shadow contents in GDB; in any case, this assumption is vaild
+ for all VxWorks-related targets. */
+
+#define CALL_DUMMY_BREAK_SET(call_dummy_addr) \
+ target_insert_breakpoint ((call_dummy_addr) + CALL_DUMMY_STOP_OFFSET, \
+ (char *) 0)
+
+#define CALL_DUMMY_BREAK_DELETE(dummy_frame_addr) \
+ target_remove_breakpoint ((dummy_frame_addr) - (CALL_DUMMY_OFFSET_IN_FRAME \
+ - CALL_DUMMY_STOP_OFFSET), \
+ (char *) 0)
+
+/* Return nonzero if the pc is executing within a CALL_DUMMY frame. */
+
+#define PC_IN_CALL_DUMMY(pc, sp, frame_address) \
+ ((pc) >= (sp) \
+ && (pc) <= (sp) + CALL_DUMMY_OFFSET_IN_FRAME + CALL_DUMMY_LENGTH)
+
+/* Defining this prevents us from trying to pass a structure-valued argument
+ to a function called via the CALL_DUMMY mechanism. This is not handled
+ properly in call_function_by_hand (), and the fix might require re-writing
+ the CALL_DUMMY handling for all targets (at least, a clean solution
+ would probably require this). Arguably, this should go in "tm-29k.h"
+ rather than here. */
+
+#define STRUCT_VAL_ARGS_UNSUPPORTED
+
+#define BKPT_OFFSET (7 * 4)
+#define BKPT_INSTR 0x72500101
+
+#undef FIX_CALL_DUMMY
+#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
+ {\
+ STUFF_I16((char *)dummyname + CONST_INSN, fun);\
+ STUFF_I16((char *)dummyname + CONST_INSN + 4, fun >> 16);\
+ *(int *)((char *)dummyname + BKPT_OFFSET) = BKPT_INSTR;\
+ }
+
+\f
+/* Offsets into jmp_buf. They are derived from VxWorks' REG_SET struct
+ (see VxWorks' setjmp.h). Note that Sun2, Sun3 and SunOS4 and VxWorks have
+ different REG_SET structs, hence different layouts for the jmp_buf struct.
+ Only JB_PC is needed for getting the saved PC value. */
+
+#define JB_ELEMENT_SIZE 4 /* size of each element in jmp_buf */
+#define JB_PC 3 /* offset of pc (pc1) in jmp_buf */
+
+/* Figure out where the longjmp will land. We expect that we have just entered
+ longjmp and haven't yet setup the stack frame, so the args are still in the
+ output regs. lr2 (LR2_REGNUM) points at the jmp_buf structure from which we
+ extract the pc (JB_PC) that we will land at. The pc is copied into ADDR.
+ This routine returns true on success */
+
+#define GET_LONGJMP_TARGET(ADDR) get_longjmp_target(ADDR)
+extern int get_longjmp_target PARAMS ((CORE_ADDR *));
+
+/* VxWorks adjusts the PC after a breakpoint has been hit. */
+
+#undef DECR_PC_AFTER_BREAK
+#define DECR_PC_AFTER_BREAK 0
+
+/* Do whatever promotions are appropriate on a value being returned
+ from a function. VAL is the user-supplied value, and FUNC_TYPE
+ is the return type of the function if known, else 0.
+
+ For the Am29k, as far as I understand, if the function return type is known,
+ cast the value to that type; otherwise, ensure that integer return values
+ fill all of gr96.
+
+ This definition really belongs in "tm-29k.h", since it applies
+ to most Am29K-based systems; but once moved into that file, it might
+ need to be redefined for all Am29K-based targets that also redefine
+ STORE_RETURN_VALUE. For now, to be safe, we define it here. */
+
+#define PROMOTE_RETURN_VALUE(val, func_type) \
+ do { \
+ if (func_type) \
+ val = value_cast (func_type, val); \
+ if ((TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_INT \
+ || TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_ENUM) \
+ && TYPE_LENGTH (VALUE_TYPE (val)) < REGISTER_RAW_SIZE (0)) \
+ val = value_cast (builtin_type_int, val); \
+ } while (0)
+
+#define SPECIAL_FRAME_CHAIN_FP get_fp_contents
+#undef FRAME_CHAIN_VALID
+#define FRAME_CHAIN_VALID(chain, thisframe) \
+ (SPECIAL_FRAME_CHAIN_FP (chain, thisframe))
+
+extern int SPECIAL_FRAME_CHAIN_FP ();
+
+extern CORE_ADDR frame_saved_call_site ();
+
+#undef PREPARE_TO_INIT_FRAME_INFO
+#define PREPARE_TO_INIT_FRAME_INFO(fci) do { \
+ long current_msp = read_register (MSP_REGNUM); \
+ if (PC_IN_CALL_DUMMY (fci->pc, current_msp, 0)) \
+ { \
+ fci->rsize = DUMMY_FRAME_RSIZE; \
+ fci->msize = 0; \
+ fci->saved_msp = \
+ read_register_stack_integer (fci->frame + DUMMY_FRAME_RSIZE - 4, 4); \
+ fci->flags |= (TRANSPARENT|MFP_USED); \
+ return; \
+ } \
+ } while (0)
projects / deliverable / binutils-gdb.git / commitdiff
