[thirdparty/binutils-gdb.git] / gdb / config / a29k / tm-vx29k.h

/* Target machine description for VxWorks on the 29k, for GDB, the GNU debugger.
   Copyright 1994, 1999 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., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "a29k/tm-a29k.h"
#include "tm-vxworks.h"

/* 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)

extern int vx29k_frame_chain_valid PARAMS ((CORE_ADDR, struct frame_info *));
#define FRAME_CHAIN_VALID(chain, thisframe) vx29k_frame_chain_valid (chain, thisframe)

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)
Commit	Line	Data
c906108c	1	/* Target machine description for VxWorks on the 29k, for GDB, the GNU debugger.
cce74817	2	Copyright 1994, 1999 Free Software Foundation, Inc.
c906108c SS	3	Contributed by Cygnus Support.
c906108c SS	4
c5aa993b	5	This file is part of GDB.
c906108c	6
c5aa993b JM	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 2 of the License, or
	10	(at your option) any later version.
c906108c	11
c5aa993b JM	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
c906108c	16
c5aa993b JM	17	You should have received a copy of the GNU General Public License
	18	along with this program; if not, write to the Free Software
	19	Foundation, Inc., 59 Temple Place - Suite 330,
	20	Boston, MA 02111-1307, USA. */
c906108c SS	21
c906108c SS	22	#include "a29k/tm-a29k.h"
cce74817	23	#include "tm-vxworks.h"
c906108c SS	24
	25	/* Number of registers in a ptrace_getregs call. */
	26
	27	#define VX_NUM_REGS (NUM_REGS)
	28
	29	/* Number of registers in a ptrace_getfpregs call. */
	30
	31	/* #define VX_SIZE_FPREGS */
	32
	33	/* This is almost certainly the wrong place for this: */
	34	#define LR2_REGNUM 34
	35	\f
	36
	37	/* Vxworks has its own CALL_DUMMY since it manages breakpoints in the kernel */
	38
	39	#undef CALL_DUMMY
	40
	41	/* Replace the breakpoint instruction in the CALL_DUMMY with a nop.
	42	For Vxworks, the breakpoint is set and deleted by calls to
	43	CALL_DUMMY_BREAK_SET and CALL_DUMMY_BREAK_DELETE. */
	44
	45	#if TARGET_BYTE_ORDER == HOST_BYTE_ORDER
	46	#define CALL_DUMMY {0x0400870f,\
	47	0x36008200\|(MSP_HW_REGNUM), \
	48	0x15000040\|(MSP_HW_REGNUM<<8)\|(MSP_HW_REGNUM<<16), \
	49	0x03ff80ff, 0x02ff80ff, 0xc8008080, 0x70400101, 0x70400101}
	50	#else /* Byte order differs. */
	51	#define CALL_DUMMY {0x0f870004,\
	52	0x00820036\|(MSP_HW_REGNUM << 24), \
	53	0x40000015\|(MSP_HW_REGNUM<<8)\|(MSP_HW_REGNUM<<16), \
	54	0xff80ff03, 0xff80ff02, 0x808000c8, 0x01014070, 0x01014070}
	55	#endif /* Byte order differs. */
	56
	57
	58	/* For the basic CALL_DUMMY definitions, see "tm-29k.h." We use the
	59	same CALL_DUMMY code, but define FIX_CALL_DUMMY (and related macros)
	60	locally to handle remote debugging of VxWorks targets. The difference
	61	is in the setting and clearing of the breakpoint at the end of the
	62	CALL_DUMMY code fragment; under VxWorks, we can't simply insert a
	63	breakpoint instruction into the code, since that would interfere with
	64	the breakpoint management mechanism on the target.
	65	Note that CALL_DUMMY is a piece of code that is used to call any C function
	66	thru VxGDB */
	67
	68	/* The offset of the instruction within the CALL_DUMMY code where we
	69	want the inferior to stop after the function call has completed.
	70	call_function_by_hand () sets a breakpoint here (via CALL_DUMMY_BREAK_SET),
	71	which POP_FRAME later deletes (via CALL_DUMMY_BREAK_DELETE). */
c5aa993b	72
c906108c	73	#define CALL_DUMMY_STOP_OFFSET (7 * 4)
c5aa993b	74
c906108c SS	75	/* The offset of the first instruction of the CALL_DUMMY code fragment
	76	relative to the frame pointer for a dummy frame. This is equal to
	77	the size of the CALL_DUMMY plus the arg_slop area size (see the diagram
	78	in "tm-29k.h"). */
	79	/* PAD : the arg_slop area size doesn't appear to me to be useful since, the
	80	call dummy code no longer modify the msp. See below. This must be checked. */
	81
	82	#define CALL_DUMMY_OFFSET_IN_FRAME (CALL_DUMMY_LENGTH + 16 * 4)
	83
	84	/* Insert the specified number of args and function address
	85	into a CALL_DUMMY sequence stored at DUMMYNAME, replace the third
	86	instruction (add msp, msp, 16*4) with a nop, and leave the final nop.
	87	We can't keep using a CALL_DUMMY that modify the msp since, for VxWorks,
	88	CALL_DUMMY is stored in the Memory Stack. Adding 16 words to the msp
	89	would then make possible for the inferior to overwrite the CALL_DUMMY code,
	90	thus creating a lot of trouble when exiting the inferior to come back in
	91	a CALL_DUMMY code that no longer exists... Furthermore, ESF are also stored
	92	from the msp in the memory stack. If msp is set higher than the dummy code,
	93	an ESF may clobber this code. */
	94
	95	#if TARGET_BYTE_ORDER == BIG_ENDIAN
	96	#define NOP_INSTR 0x70400101
	97	#else /* Target is little endian */
	98	#define NOP_INSTR 0x01014070
	99	#endif
	100
	101	#undef FIX_CALL_DUMMY
	102	#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
	103	{ \
	104	(int )((char *)dummyname + 8) = NOP_INSTR; \
	105	STUFF_I16((char *)dummyname + CONST_INSN, fun); \
	106	STUFF_I16((char *)dummyname + CONST_INSN + 4, fun >> 16); \
	107	}
	108
	109	/* For VxWorks, CALL_DUMMY must be stored in the stack of the task that is
	110	being debugged and executed "in the context of" this task */
	111
	112	#undef CALL_DUMMY_LOCATION
	113	#define CALL_DUMMY_LOCATION ON_STACK
	114
	115	/* Set or delete a breakpoint at the location within a CALL_DUMMY code
	116	fragment where we want the target program to stop after the function
	117	call is complete. CALL_DUMMY_ADDR is the address of the first
	118	instruction in the CALL_DUMMY. DUMMY_FRAME_ADDR is the value of the
	119	frame pointer in the dummy frame.
	120
	121	NOTE: in the both of the following definitions, we take advantage of
c5aa993b JM	122	knowledge of the implementation of the target breakpoint operation,
	123	in that we pass a null pointer as the second argument. It seems
	124	reasonable to assume that any target requiring the use of
	125	CALL_DUMMY_BREAK_{SET,DELETE} will not store the breakpoint
	126	shadow contents in GDB; in any case, this assumption is vaild
	127	for all VxWorks-related targets. */
c906108c SS	128
	129	#define CALL_DUMMY_BREAK_SET(call_dummy_addr) \
	130	target_insert_breakpoint ((call_dummy_addr) + CALL_DUMMY_STOP_OFFSET, \
	131	(char *) 0)
	132
	133	#define CALL_DUMMY_BREAK_DELETE(dummy_frame_addr) \
	134	target_remove_breakpoint ((dummy_frame_addr) - (CALL_DUMMY_OFFSET_IN_FRAME \
	135	- CALL_DUMMY_STOP_OFFSET), \
	136	(char *) 0)
	137
	138	/* Return nonzero if the pc is executing within a CALL_DUMMY frame. */
	139
	140	#define PC_IN_CALL_DUMMY(pc, sp, frame_address) \
	141	((pc) >= (sp) \
	142	&& (pc) <= (sp) + CALL_DUMMY_OFFSET_IN_FRAME + CALL_DUMMY_LENGTH)
	143
	144	/* Defining this prevents us from trying to pass a structure-valued argument
	145	to a function called via the CALL_DUMMY mechanism. This is not handled
	146	properly in call_function_by_hand (), and the fix might require re-writing
	147	the CALL_DUMMY handling for all targets (at least, a clean solution
	148	would probably require this). Arguably, this should go in "tm-29k.h"
	149	rather than here. */
c5aa993b	150
c906108c SS	151	#define STRUCT_VAL_ARGS_UNSUPPORTED
	152
	153	#define BKPT_OFFSET (7 * 4)
	154	#define BKPT_INSTR 0x72500101
	155
	156	#undef FIX_CALL_DUMMY
	157	#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
	158	{\
	159	STUFF_I16((char *)dummyname + CONST_INSN, fun);\
	160	STUFF_I16((char *)dummyname + CONST_INSN + 4, fun >> 16);\
	161	(int )((char *)dummyname + BKPT_OFFSET) = BKPT_INSTR;\
	162	}
c906108c	163	\f
c5aa993b	164
c906108c SS	165	/* Offsets into jmp_buf. They are derived from VxWorks' REG_SET struct
	166	(see VxWorks' setjmp.h). Note that Sun2, Sun3 and SunOS4 and VxWorks have
	167	different REG_SET structs, hence different layouts for the jmp_buf struct.
	168	Only JB_PC is needed for getting the saved PC value. */
	169
c5aa993b	170	#define JB_ELEMENT_SIZE 4 /* size of each element in jmp_buf */
c906108c	171	#define JB_PC 3 /* offset of pc (pc1) in jmp_buf */
c5aa993b	172
c906108c SS	173	/* Figure out where the longjmp will land. We expect that we have just entered
	174	longjmp and haven't yet setup the stack frame, so the args are still in the
	175	output regs. lr2 (LR2_REGNUM) points at the jmp_buf structure from which we
	176	extract the pc (JB_PC) that we will land at. The pc is copied into ADDR.
	177	This routine returns true on success */
	178
	179	#define GET_LONGJMP_TARGET(ADDR) get_longjmp_target(ADDR)
	180	extern int get_longjmp_target PARAMS ((CORE_ADDR *));
	181
	182	/* VxWorks adjusts the PC after a breakpoint has been hit. */
c5aa993b	183
c906108c SS	184	#undef DECR_PC_AFTER_BREAK
	185	#define DECR_PC_AFTER_BREAK 0
	186
	187	/* Do whatever promotions are appropriate on a value being returned
	188	from a function. VAL is the user-supplied value, and FUNC_TYPE
	189	is the return type of the function if known, else 0.
c5aa993b	190
c906108c SS	191	For the Am29k, as far as I understand, if the function return type is known,
	192	cast the value to that type; otherwise, ensure that integer return values
	193	fill all of gr96.
	194
	195	This definition really belongs in "tm-29k.h", since it applies
	196	to most Am29K-based systems; but once moved into that file, it might
	197	need to be redefined for all Am29K-based targets that also redefine
	198	STORE_RETURN_VALUE. For now, to be safe, we define it here. */
c5aa993b	199
c906108c SS	200	#define PROMOTE_RETURN_VALUE(val, func_type) \
	201	do { \
	202	if (func_type) \
	203	val = value_cast (func_type, val); \
	204	if ((TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_INT \
	205	\|\| TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_ENUM) \
	206	&& TYPE_LENGTH (VALUE_TYPE (val)) < REGISTER_RAW_SIZE (0)) \
	207	val = value_cast (builtin_type_int, val); \
	208	} while (0)
	209
	210	extern int vx29k_frame_chain_valid PARAMS ((CORE_ADDR, struct frame_info *));
	211	#define FRAME_CHAIN_VALID(chain, thisframe) vx29k_frame_chain_valid (chain, thisframe)
	212
	213	extern CORE_ADDR frame_saved_call_site ();
	214
	215	#undef PREPARE_TO_INIT_FRAME_INFO
	216	#define PREPARE_TO_INIT_FRAME_INFO(fci) do { \
	217	long current_msp = read_register (MSP_REGNUM); \
	218	if (PC_IN_CALL_DUMMY (fci->pc, current_msp, 0)) \
	219	{ \
	220	fci->rsize = DUMMY_FRAME_RSIZE; \
	221	fci->msize = 0; \
	222	fci->saved_msp = \
	223	read_register_stack_integer (fci->frame + DUMMY_FRAME_RSIZE - 4, 4); \
	224	fci->flags \|= (TRANSPARENT\|MFP_USED); \
	225	return; \
	226	} \
	227	} while (0)