1 /* Target-dependent code for the Motorola 68000 series.
3 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2000,
4 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 #include "dwarf2-frame.h"
26 #include "frame-base.h"
27 #include "frame-unwind.h"
28 #include "floatformat.h"
32 #include "gdb_string.h"
33 #include "gdb_assert.h"
36 #include "arch-utils.h"
40 #include "m68k-tdep.h"
43 #define P_LINKL_FP 0x480e
44 #define P_LINKW_FP 0x4e56
45 #define P_PEA_FP 0x4856
46 #define P_MOVEAL_SP_FP 0x2c4f
47 #define P_ADDAW_SP 0xdefc
48 #define P_ADDAL_SP 0xdffc
49 #define P_SUBQW_SP 0x514f
50 #define P_SUBQL_SP 0x518f
51 #define P_LEA_SP_SP 0x4fef
52 #define P_LEA_PC_A5 0x4bfb0170
53 #define P_FMOVEMX_SP 0xf227
54 #define P_MOVEL_SP 0x2f00
55 #define P_MOVEML_SP 0x48e7
58 #define REGISTER_BYTES_FP (16*4 + 8 + 8*12 + 3*4)
59 #define REGISTER_BYTES_NOFP (16*4 + 8)
61 /* Offset from SP to first arg on stack at first instruction of a function */
62 #define SP_ARG0 (1 * 4)
64 #if !defined (BPT_VECTOR)
65 #define BPT_VECTOR 0xf
68 static const unsigned char *
69 m68k_local_breakpoint_from_pc (CORE_ADDR
*pcptr
, int *lenptr
)
71 static unsigned char break_insn
[] = {0x4e, (0x40 | BPT_VECTOR
)};
72 *lenptr
= sizeof (break_insn
);
78 m68k_register_bytes_ok (long numbytes
)
80 return ((numbytes
== REGISTER_BYTES_FP
)
81 || (numbytes
== REGISTER_BYTES_NOFP
));
84 /* Return the GDB type object for the "standard" data type of data in
85 register N. This should be int for D0-D7, SR, FPCONTROL and
86 FPSTATUS, long double for FP0-FP7, and void pointer for all others
87 (A0-A7, PC, FPIADDR). Note, for registers which contain
88 addresses return pointer to void, not pointer to char, because we
89 don't want to attempt to print the string after printing the
93 m68k_register_type (struct gdbarch
*gdbarch
, int regnum
)
95 if (regnum
>= FP0_REGNUM
&& regnum
<= FP0_REGNUM
+ 7)
96 return builtin_type_m68881_ext
;
98 if (regnum
== M68K_FPI_REGNUM
|| regnum
== PC_REGNUM
)
99 return builtin_type_void_func_ptr
;
101 if (regnum
== M68K_FPC_REGNUM
|| regnum
== M68K_FPS_REGNUM
102 || regnum
== PS_REGNUM
)
103 return builtin_type_int32
;
105 if (regnum
>= M68K_A0_REGNUM
&& regnum
<= M68K_A0_REGNUM
+ 7)
106 return builtin_type_void_data_ptr
;
108 return builtin_type_int32
;
111 /* Function: m68k_register_name
112 Returns the name of the standard m68k register regnum. */
115 m68k_register_name (int regnum
)
117 static char *register_names
[] = {
118 "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7",
119 "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp",
121 "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7",
122 "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags"
126 regnum
>= sizeof (register_names
) / sizeof (register_names
[0]))
127 internal_error (__FILE__
, __LINE__
,
128 "m68k_register_name: illegal register number %d", regnum
);
130 return register_names
[regnum
];
133 /* There is a fair number of calling conventions that are in somewhat
134 wide use. The 68000/08/10 don't support an FPU, not even as a
135 coprocessor. All function return values are stored in %d0/%d1.
136 Structures are returned in a static buffer, a pointer to which is
137 returned in %d0. This means that functions returning a structure
138 are not re-entrant. To avoid this problem some systems use a
139 convention where the caller passes a pointer to a buffer in %a1
140 where the return values is to be stored. This convention is the
141 default, and is implemented in the function m68k_return_value.
143 The 68020/030/040/060 do support an FPU, either as a coprocessor
144 (68881/2) or built-in (68040/68060). That's why System V release 4
145 (SVR4) instroduces a new calling convention specified by the SVR4
146 psABI. Integer values are returned in %d0/%d1, pointer return
147 values in %a0 and floating values in %fp0. When calling functions
148 returning a structure the caller should pass a pointer to a buffer
149 for the return value in %a0. This convention is implemented in the
150 function m68k_svr4_return_value, and by appropriately setting the
151 struct_value_regnum member of `struct gdbarch_tdep'.
153 GNU/Linux returns values in the same way as SVR4 does, but uses %a1
154 for passing the structure return value buffer.
156 GCC can also generate code where small structures are returned in
157 %d0/%d1 instead of in memory by using -freg-struct-return. This is
158 the default on NetBSD a.out, OpenBSD and GNU/Linux and several
159 embedded systems. This convention is implemented by setting the
160 struct_return member of `struct gdbarch_tdep' to reg_struct_return. */
162 /* Read a function return value of TYPE from REGCACHE, and copy that
166 m68k_extract_return_value (struct type
*type
, struct regcache
*regcache
,
169 int len
= TYPE_LENGTH (type
);
170 char buf
[M68K_MAX_REGISTER_SIZE
];
174 regcache_raw_read (regcache
, M68K_D0_REGNUM
, buf
);
175 memcpy (valbuf
, buf
+ (4 - len
), len
);
179 regcache_raw_read (regcache
, M68K_D0_REGNUM
, buf
);
180 memcpy (valbuf
, buf
+ (8 - len
), len
- 4);
181 regcache_raw_read (regcache
, M68K_D1_REGNUM
,
182 (char *) valbuf
+ (len
- 4));
185 internal_error (__FILE__
, __LINE__
,
186 "Cannot extract return value of %d bytes long.", len
);
190 m68k_svr4_extract_return_value (struct type
*type
, struct regcache
*regcache
,
193 int len
= TYPE_LENGTH (type
);
194 char buf
[M68K_MAX_REGISTER_SIZE
];
196 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
198 regcache_raw_read (regcache
, M68K_FP0_REGNUM
, buf
);
199 convert_typed_floating (buf
, builtin_type_m68881_ext
, valbuf
, type
);
201 else if (TYPE_CODE (type
) == TYPE_CODE_PTR
&& len
== 4)
202 regcache_raw_read (regcache
, M68K_A0_REGNUM
, valbuf
);
204 m68k_extract_return_value (type
, regcache
, valbuf
);
207 /* Write a function return value of TYPE from VALBUF into REGCACHE. */
210 m68k_store_return_value (struct type
*type
, struct regcache
*regcache
,
213 int len
= TYPE_LENGTH (type
);
216 regcache_raw_write_part (regcache
, M68K_D0_REGNUM
, 4 - len
, len
, valbuf
);
219 regcache_raw_write_part (regcache
, M68K_D0_REGNUM
, 8 - len
,
221 regcache_raw_write (regcache
, M68K_D1_REGNUM
,
222 (char *) valbuf
+ (len
- 4));
225 internal_error (__FILE__
, __LINE__
,
226 "Cannot store return value of %d bytes long.", len
);
230 m68k_svr4_store_return_value (struct type
*type
, struct regcache
*regcache
,
233 int len
= TYPE_LENGTH (type
);
235 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
237 char buf
[M68K_MAX_REGISTER_SIZE
];
238 convert_typed_floating (valbuf
, type
, buf
, builtin_type_m68881_ext
);
239 regcache_raw_write (regcache
, M68K_FP0_REGNUM
, buf
);
241 else if (TYPE_CODE (type
) == TYPE_CODE_PTR
&& len
== 4)
243 regcache_raw_write (regcache
, M68K_A0_REGNUM
, valbuf
);
244 regcache_raw_write (regcache
, M68K_D0_REGNUM
, valbuf
);
247 m68k_store_return_value (type
, regcache
, valbuf
);
250 /* Return non-zero if TYPE, which is assumed to be a structure or
251 union type, should be returned in registers for architecture
255 m68k_reg_struct_return_p (struct gdbarch
*gdbarch
, struct type
*type
)
257 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
258 enum type_code code
= TYPE_CODE (type
);
259 int len
= TYPE_LENGTH (type
);
261 gdb_assert (code
== TYPE_CODE_STRUCT
|| code
== TYPE_CODE_UNION
);
263 if (tdep
->struct_return
== pcc_struct_return
)
266 return (len
== 1 || len
== 2 || len
== 4 || len
== 8);
269 /* Determine, for architecture GDBARCH, how a return value of TYPE
270 should be returned. If it is supposed to be returned in registers,
271 and READBUF is non-zero, read the appropriate value from REGCACHE,
272 and copy it into READBUF. If WRITEBUF is non-zero, write the value
273 from WRITEBUF into REGCACHE. */
275 static enum return_value_convention
276 m68k_return_value (struct gdbarch
*gdbarch
, struct type
*type
,
277 struct regcache
*regcache
, void *readbuf
,
278 const void *writebuf
)
280 enum type_code code
= TYPE_CODE (type
);
282 if ((code
== TYPE_CODE_STRUCT
|| code
== TYPE_CODE_UNION
)
283 && !m68k_reg_struct_return_p (gdbarch
, type
))
284 return RETURN_VALUE_STRUCT_CONVENTION
;
286 /* GCC returns a `long double' in memory. */
287 if (code
== TYPE_CODE_FLT
&& TYPE_LENGTH (type
) == 12)
288 return RETURN_VALUE_STRUCT_CONVENTION
;
291 m68k_extract_return_value (type
, regcache
, readbuf
);
293 m68k_store_return_value (type
, regcache
, writebuf
);
295 return RETURN_VALUE_REGISTER_CONVENTION
;
298 static enum return_value_convention
299 m68k_svr4_return_value (struct gdbarch
*gdbarch
, struct type
*type
,
300 struct regcache
*regcache
, void *readbuf
,
301 const void *writebuf
)
303 enum type_code code
= TYPE_CODE (type
);
305 if ((code
== TYPE_CODE_STRUCT
|| code
== TYPE_CODE_UNION
)
306 && !m68k_reg_struct_return_p (gdbarch
, type
))
307 return RETURN_VALUE_STRUCT_CONVENTION
;
309 /* This special case is for structures consisting of a single
310 `float' or `double' member. These structures are returned in
311 %fp0. For these structures, we call ourselves recursively,
312 changing TYPE into the type of the first member of the structure.
313 Since that should work for all structures that have only one
314 member, we don't bother to check the member's type here. */
315 if (code
== TYPE_CODE_STRUCT
&& TYPE_NFIELDS (type
) == 1)
317 type
= check_typedef (TYPE_FIELD_TYPE (type
, 0));
318 return m68k_svr4_return_value (gdbarch
, type
, regcache
,
323 m68k_svr4_extract_return_value (type
, regcache
, readbuf
);
325 m68k_svr4_store_return_value (type
, regcache
, writebuf
);
327 return RETURN_VALUE_REGISTER_CONVENTION
;
332 m68k_push_dummy_call (struct gdbarch
*gdbarch
, CORE_ADDR func_addr
,
333 struct regcache
*regcache
, CORE_ADDR bp_addr
, int nargs
,
334 struct value
**args
, CORE_ADDR sp
, int struct_return
,
335 CORE_ADDR struct_addr
)
337 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
341 /* Push arguments in reverse order. */
342 for (i
= nargs
- 1; i
>= 0; i
--)
344 struct type
*value_type
= VALUE_ENCLOSING_TYPE (args
[i
]);
345 int len
= TYPE_LENGTH (value_type
);
346 int container_len
= (len
+ 3) & ~3;
349 /* Non-scalars bigger than 4 bytes are left aligned, others are
351 if ((TYPE_CODE (value_type
) == TYPE_CODE_STRUCT
352 || TYPE_CODE (value_type
) == TYPE_CODE_UNION
353 || TYPE_CODE (value_type
) == TYPE_CODE_ARRAY
)
357 offset
= container_len
- len
;
359 write_memory (sp
+ offset
, VALUE_CONTENTS_ALL (args
[i
]), len
);
362 /* Store struct value address. */
365 store_unsigned_integer (buf
, 4, struct_addr
);
366 regcache_cooked_write (regcache
, tdep
->struct_value_regnum
, buf
);
369 /* Store return address. */
371 store_unsigned_integer (buf
, 4, bp_addr
);
372 write_memory (sp
, buf
, 4);
374 /* Finally, update the stack pointer... */
375 store_unsigned_integer (buf
, 4, sp
);
376 regcache_cooked_write (regcache
, M68K_SP_REGNUM
, buf
);
378 /* ...and fake a frame pointer. */
379 regcache_cooked_write (regcache
, M68K_FP_REGNUM
, buf
);
381 /* DWARF2/GCC uses the stack address *before* the function call as a
386 struct m68k_frame_cache
393 /* Saved registers. */
394 CORE_ADDR saved_regs
[M68K_NUM_REGS
];
397 /* Stack space reserved for local variables. */
401 /* Allocate and initialize a frame cache. */
403 static struct m68k_frame_cache
*
404 m68k_alloc_frame_cache (void)
406 struct m68k_frame_cache
*cache
;
409 cache
= FRAME_OBSTACK_ZALLOC (struct m68k_frame_cache
);
413 cache
->sp_offset
= -4;
416 /* Saved registers. We initialize these to -1 since zero is a valid
417 offset (that's where %fp is supposed to be stored). */
418 for (i
= 0; i
< M68K_NUM_REGS
; i
++)
419 cache
->saved_regs
[i
] = -1;
421 /* Frameless until proven otherwise. */
427 /* Check whether PC points at a code that sets up a new stack frame.
428 If so, it updates CACHE and returns the address of the first
429 instruction after the sequence that sets removes the "hidden"
430 argument from the stack or CURRENT_PC, whichever is smaller.
431 Otherwise, return PC. */
434 m68k_analyze_frame_setup (CORE_ADDR pc
, CORE_ADDR current_pc
,
435 struct m68k_frame_cache
*cache
)
439 if (pc
>= current_pc
)
442 op
= read_memory_unsigned_integer (pc
, 2);
444 if (op
== P_LINKW_FP
|| op
== P_LINKL_FP
|| op
== P_PEA_FP
)
446 cache
->saved_regs
[M68K_FP_REGNUM
] = 0;
447 cache
->sp_offset
+= 4;
448 if (op
== P_LINKW_FP
)
450 /* link.w %fp, #-N */
451 /* link.w %fp, #0; adda.l #-N, %sp */
452 cache
->locals
= -read_memory_integer (pc
+ 2, 2);
454 if (pc
+ 4 < current_pc
&& cache
->locals
== 0)
456 op
= read_memory_unsigned_integer (pc
+ 4, 2);
457 if (op
== P_ADDAL_SP
)
459 cache
->locals
= read_memory_integer (pc
+ 6, 4);
466 else if (op
== P_LINKL_FP
)
468 /* link.l %fp, #-N */
469 cache
->locals
= -read_memory_integer (pc
+ 2, 4);
474 /* pea (%fp); movea.l %sp, %fp */
477 if (pc
+ 2 < current_pc
)
479 op
= read_memory_unsigned_integer (pc
+ 2, 2);
481 if (op
== P_MOVEAL_SP_FP
)
483 /* move.l %sp, %fp */
491 else if ((op
& 0170777) == P_SUBQW_SP
|| (op
& 0170777) == P_SUBQL_SP
)
493 /* subq.[wl] #N,%sp */
494 /* subq.[wl] #8,%sp; subq.[wl] #N,%sp */
495 cache
->locals
= (op
& 07000) == 0 ? 8 : (op
& 07000) >> 9;
496 if (pc
+ 2 < current_pc
)
498 op
= read_memory_unsigned_integer (pc
+ 2, 2);
499 if ((op
& 0170777) == P_SUBQW_SP
|| (op
& 0170777) == P_SUBQL_SP
)
501 cache
->locals
+= (op
& 07000) == 0 ? 8 : (op
& 07000) >> 9;
507 else if (op
== P_ADDAW_SP
|| op
== P_LEA_SP_SP
)
510 /* lea (-N,%sp),%sp */
511 cache
->locals
= -read_memory_integer (pc
+ 2, 2);
514 else if (op
== P_ADDAL_SP
)
517 cache
->locals
= -read_memory_integer (pc
+ 2, 4);
524 /* Check whether PC points at code that saves registers on the stack.
525 If so, it updates CACHE and returns the address of the first
526 instruction after the register saves or CURRENT_PC, whichever is
527 smaller. Otherwise, return PC. */
530 m68k_analyze_register_saves (CORE_ADDR pc
, CORE_ADDR current_pc
,
531 struct m68k_frame_cache
*cache
)
533 if (cache
->locals
>= 0)
539 offset
= -4 - cache
->locals
;
540 while (pc
< current_pc
)
542 op
= read_memory_unsigned_integer (pc
, 2);
543 if (op
== P_FMOVEMX_SP
)
545 /* fmovem.x REGS,-(%sp) */
546 op
= read_memory_unsigned_integer (pc
+ 2, 2);
547 if ((op
& 0xff00) == 0xe000)
550 for (i
= 0; i
< 16; i
++, mask
>>= 1)
554 cache
->saved_regs
[i
+ M68K_FP0_REGNUM
] = offset
;
563 else if ((op
& 0170677) == P_MOVEL_SP
)
565 /* move.l %R,-(%sp) */
566 regno
= ((op
& 07000) >> 9) | ((op
& 0100) >> 3);
567 cache
->saved_regs
[regno
] = offset
;
571 else if (op
== P_MOVEML_SP
)
573 /* movem.l REGS,-(%sp) */
574 mask
= read_memory_unsigned_integer (pc
+ 2, 2);
575 for (i
= 0; i
< 16; i
++, mask
>>= 1)
579 cache
->saved_regs
[15 - i
] = offset
;
594 /* Do a full analysis of the prologue at PC and update CACHE
595 accordingly. Bail out early if CURRENT_PC is reached. Return the
596 address where the analysis stopped.
598 We handle all cases that can be generated by gcc.
600 For allocating a stack frame:
604 pea (%fp); move.l %sp,%fp
605 link.w %a6,#0; add.l #-N,%sp
608 subq.w #8,%sp; subq.w #N-8,%sp
613 For saving registers:
617 move.l R1,-(%sp); move.l R2,-(%sp)
620 For setting up the PIC register:
627 m68k_analyze_prologue (CORE_ADDR pc
, CORE_ADDR current_pc
,
628 struct m68k_frame_cache
*cache
)
632 pc
= m68k_analyze_frame_setup (pc
, current_pc
, cache
);
633 pc
= m68k_analyze_register_saves (pc
, current_pc
, cache
);
634 if (pc
>= current_pc
)
637 /* Check for GOT setup. */
638 op
= read_memory_unsigned_integer (pc
, 4);
639 if (op
== P_LEA_PC_A5
)
641 /* lea (%pc,N),%a5 */
648 /* Return PC of first real instruction. */
651 m68k_skip_prologue (CORE_ADDR start_pc
)
653 struct m68k_frame_cache cache
;
658 pc
= m68k_analyze_prologue (start_pc
, (CORE_ADDR
) -1, &cache
);
659 if (cache
.locals
< 0)
665 m68k_unwind_pc (struct gdbarch
*gdbarch
, struct frame_info
*next_frame
)
669 frame_unwind_register (next_frame
, PC_REGNUM
, buf
);
670 return extract_typed_address (buf
, builtin_type_void_func_ptr
);
675 static struct m68k_frame_cache
*
676 m68k_frame_cache (struct frame_info
*next_frame
, void **this_cache
)
678 struct m68k_frame_cache
*cache
;
685 cache
= m68k_alloc_frame_cache ();
688 /* In principle, for normal frames, %fp holds the frame pointer,
689 which holds the base address for the current stack frame.
690 However, for functions that don't need it, the frame pointer is
691 optional. For these "frameless" functions the frame pointer is
692 actually the frame pointer of the calling frame. Signal
693 trampolines are just a special case of a "frameless" function.
694 They (usually) share their frame pointer with the frame that was
695 in progress when the signal occurred. */
697 frame_unwind_register (next_frame
, M68K_FP_REGNUM
, buf
);
698 cache
->base
= extract_unsigned_integer (buf
, 4);
699 if (cache
->base
== 0)
702 /* For normal frames, %pc is stored at 4(%fp). */
703 cache
->saved_regs
[M68K_PC_REGNUM
] = 4;
705 cache
->pc
= frame_func_unwind (next_frame
);
707 m68k_analyze_prologue (cache
->pc
, frame_pc_unwind (next_frame
), cache
);
709 if (cache
->locals
< 0)
711 /* We didn't find a valid frame, which means that CACHE->base
712 currently holds the frame pointer for our calling frame. If
713 we're at the start of a function, or somewhere half-way its
714 prologue, the function's frame probably hasn't been fully
715 setup yet. Try to reconstruct the base address for the stack
716 frame by looking at the stack pointer. For truly "frameless"
717 functions this might work too. */
719 frame_unwind_register (next_frame
, M68K_SP_REGNUM
, buf
);
720 cache
->base
= extract_unsigned_integer (buf
, 4) + cache
->sp_offset
;
723 /* Now that we have the base address for the stack frame we can
724 calculate the value of %sp in the calling frame. */
725 cache
->saved_sp
= cache
->base
+ 8;
727 /* Adjust all the saved registers such that they contain addresses
728 instead of offsets. */
729 for (i
= 0; i
< M68K_NUM_REGS
; i
++)
730 if (cache
->saved_regs
[i
] != -1)
731 cache
->saved_regs
[i
] += cache
->base
;
737 m68k_frame_this_id (struct frame_info
*next_frame
, void **this_cache
,
738 struct frame_id
*this_id
)
740 struct m68k_frame_cache
*cache
= m68k_frame_cache (next_frame
, this_cache
);
742 /* This marks the outermost frame. */
743 if (cache
->base
== 0)
746 /* See the end of m68k_push_dummy_call. */
747 *this_id
= frame_id_build (cache
->base
+ 8, cache
->pc
);
751 m68k_frame_prev_register (struct frame_info
*next_frame
, void **this_cache
,
752 int regnum
, int *optimizedp
,
753 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
754 int *realnump
, void *valuep
)
756 struct m68k_frame_cache
*cache
= m68k_frame_cache (next_frame
, this_cache
);
758 gdb_assert (regnum
>= 0);
760 if (regnum
== M68K_SP_REGNUM
&& cache
->saved_sp
)
768 /* Store the value. */
769 store_unsigned_integer (valuep
, 4, cache
->saved_sp
);
774 if (regnum
< M68K_NUM_REGS
&& cache
->saved_regs
[regnum
] != -1)
777 *lvalp
= lval_memory
;
778 *addrp
= cache
->saved_regs
[regnum
];
782 /* Read the value in from memory. */
783 read_memory (*addrp
, valuep
,
784 register_size (current_gdbarch
, regnum
));
789 frame_register_unwind (next_frame
, regnum
,
790 optimizedp
, lvalp
, addrp
, realnump
, valuep
);
793 static const struct frame_unwind m68k_frame_unwind
=
797 m68k_frame_prev_register
800 static const struct frame_unwind
*
801 m68k_frame_sniffer (struct frame_info
*next_frame
)
803 return &m68k_frame_unwind
;
807 m68k_frame_base_address (struct frame_info
*next_frame
, void **this_cache
)
809 struct m68k_frame_cache
*cache
= m68k_frame_cache (next_frame
, this_cache
);
814 static const struct frame_base m68k_frame_base
=
817 m68k_frame_base_address
,
818 m68k_frame_base_address
,
819 m68k_frame_base_address
822 static struct frame_id
823 m68k_unwind_dummy_id (struct gdbarch
*gdbarch
, struct frame_info
*next_frame
)
828 frame_unwind_register (next_frame
, M68K_FP_REGNUM
, buf
);
829 fp
= extract_unsigned_integer (buf
, 4);
831 /* See the end of m68k_push_dummy_call. */
832 return frame_id_build (fp
+ 8, frame_pc_unwind (next_frame
));
835 #ifdef USE_PROC_FS /* Target dependent support for /proc */
837 #include <sys/procfs.h>
839 /* Prototypes for supply_gregset etc. */
842 /* The /proc interface divides the target machine's register set up into
843 two different sets, the general register set (gregset) and the floating
844 point register set (fpregset). For each set, there is an ioctl to get
845 the current register set and another ioctl to set the current values.
847 The actual structure passed through the ioctl interface is, of course,
848 naturally machine dependent, and is different for each set of registers.
849 For the m68k for example, the general register set is typically defined
852 typedef int gregset_t[18];
858 and the floating point set by:
860 typedef struct fpregset {
864 int f_fpregs[8][3]; (8 regs, 96 bits each)
867 These routines provide the packing and unpacking of gregset_t and
868 fpregset_t formatted data.
872 /* Atari SVR4 has R_SR but not R_PS */
874 #if !defined (R_PS) && defined (R_SR)
878 /* Given a pointer to a general register set in /proc format (gregset_t *),
879 unpack the register contents and supply them as gdb's idea of the current
883 supply_gregset (gregset_t
*gregsetp
)
886 greg_t
*regp
= (greg_t
*) gregsetp
;
888 for (regi
= 0; regi
< R_PC
; regi
++)
890 supply_register (regi
, (char *) (regp
+ regi
));
892 supply_register (PS_REGNUM
, (char *) (regp
+ R_PS
));
893 supply_register (PC_REGNUM
, (char *) (regp
+ R_PC
));
897 fill_gregset (gregset_t
*gregsetp
, int regno
)
900 greg_t
*regp
= (greg_t
*) gregsetp
;
902 for (regi
= 0; regi
< R_PC
; regi
++)
904 if (regno
== -1 || regno
== regi
)
905 regcache_collect (regi
, regp
+ regi
);
907 if (regno
== -1 || regno
== PS_REGNUM
)
908 regcache_collect (PS_REGNUM
, regp
+ R_PS
);
909 if (regno
== -1 || regno
== PC_REGNUM
)
910 regcache_collect (PC_REGNUM
, regp
+ R_PC
);
913 #if defined (FP0_REGNUM)
915 /* Given a pointer to a floating point register set in /proc format
916 (fpregset_t *), unpack the register contents and supply them as gdb's
917 idea of the current floating point register values. */
920 supply_fpregset (fpregset_t
*fpregsetp
)
925 for (regi
= FP0_REGNUM
; regi
< M68K_FPC_REGNUM
; regi
++)
927 from
= (char *) &(fpregsetp
->f_fpregs
[regi
- FP0_REGNUM
][0]);
928 supply_register (regi
, from
);
930 supply_register (M68K_FPC_REGNUM
, (char *) &(fpregsetp
->f_pcr
));
931 supply_register (M68K_FPS_REGNUM
, (char *) &(fpregsetp
->f_psr
));
932 supply_register (M68K_FPI_REGNUM
, (char *) &(fpregsetp
->f_fpiaddr
));
935 /* Given a pointer to a floating point register set in /proc format
936 (fpregset_t *), update the register specified by REGNO from gdb's idea
937 of the current floating point register set. If REGNO is -1, update
941 fill_fpregset (fpregset_t
*fpregsetp
, int regno
)
945 for (regi
= FP0_REGNUM
; regi
< M68K_FPC_REGNUM
; regi
++)
947 if (regno
== -1 || regno
== regi
)
948 regcache_collect (regi
, &fpregsetp
->f_fpregs
[regi
- FP0_REGNUM
][0]);
950 if (regno
== -1 || regno
== M68K_FPC_REGNUM
)
951 regcache_collect (M68K_FPC_REGNUM
, &fpregsetp
->f_pcr
);
952 if (regno
== -1 || regno
== M68K_FPS_REGNUM
)
953 regcache_collect (M68K_FPS_REGNUM
, &fpregsetp
->f_psr
);
954 if (regno
== -1 || regno
== M68K_FPI_REGNUM
)
955 regcache_collect (M68K_FPI_REGNUM
, &fpregsetp
->f_fpiaddr
);
958 #endif /* defined (FP0_REGNUM) */
960 #endif /* USE_PROC_FS */
962 /* Figure out where the longjmp will land. Slurp the args out of the stack.
963 We expect the first arg to be a pointer to the jmp_buf structure from which
964 we extract the pc (JB_PC) that we will land at. The pc is copied into PC.
965 This routine returns true on success. */
968 m68k_get_longjmp_target (CORE_ADDR
*pc
)
971 CORE_ADDR sp
, jb_addr
;
972 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
976 internal_error (__FILE__
, __LINE__
,
977 "m68k_get_longjmp_target: not implemented");
981 buf
= alloca (TARGET_PTR_BIT
/ TARGET_CHAR_BIT
);
982 sp
= read_register (SP_REGNUM
);
984 if (target_read_memory (sp
+ SP_ARG0
, /* Offset of first arg on stack */
985 buf
, TARGET_PTR_BIT
/ TARGET_CHAR_BIT
))
988 jb_addr
= extract_unsigned_integer (buf
, TARGET_PTR_BIT
/ TARGET_CHAR_BIT
);
990 if (target_read_memory (jb_addr
+ tdep
->jb_pc
* tdep
->jb_elt_size
, buf
,
991 TARGET_PTR_BIT
/ TARGET_CHAR_BIT
))
994 *pc
= extract_unsigned_integer (buf
, TARGET_PTR_BIT
/ TARGET_CHAR_BIT
);
999 /* System V Release 4 (SVR4). */
1002 m68k_svr4_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
1004 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
1006 /* SVR4 uses a different calling convention. */
1007 set_gdbarch_return_value (gdbarch
, m68k_svr4_return_value
);
1009 /* SVR4 uses %a0 instead of %a1. */
1010 tdep
->struct_value_regnum
= M68K_A0_REGNUM
;
1014 /* Function: m68k_gdbarch_init
1015 Initializer function for the m68k gdbarch vector.
1016 Called by gdbarch. Sets up the gdbarch vector(s) for this target. */
1018 static struct gdbarch
*
1019 m68k_gdbarch_init (struct gdbarch_info info
, struct gdbarch_list
*arches
)
1021 struct gdbarch_tdep
*tdep
= NULL
;
1022 struct gdbarch
*gdbarch
;
1024 /* find a candidate among the list of pre-declared architectures. */
1025 arches
= gdbarch_list_lookup_by_info (arches
, &info
);
1027 return (arches
->gdbarch
);
1029 tdep
= xmalloc (sizeof (struct gdbarch_tdep
));
1030 gdbarch
= gdbarch_alloc (&info
, tdep
);
1032 set_gdbarch_long_double_format (gdbarch
, &floatformat_m68881_ext
);
1033 set_gdbarch_long_double_bit (gdbarch
, 96);
1035 set_gdbarch_skip_prologue (gdbarch
, m68k_skip_prologue
);
1036 set_gdbarch_breakpoint_from_pc (gdbarch
, m68k_local_breakpoint_from_pc
);
1038 /* Stack grows down. */
1039 set_gdbarch_inner_than (gdbarch
, core_addr_lessthan
);
1041 set_gdbarch_believe_pcc_promotion (gdbarch
, 1);
1042 set_gdbarch_decr_pc_after_break (gdbarch
, 2);
1044 set_gdbarch_frame_args_skip (gdbarch
, 8);
1046 set_gdbarch_register_type (gdbarch
, m68k_register_type
);
1047 set_gdbarch_register_name (gdbarch
, m68k_register_name
);
1048 set_gdbarch_num_regs (gdbarch
, 29);
1049 set_gdbarch_register_bytes_ok (gdbarch
, m68k_register_bytes_ok
);
1050 set_gdbarch_sp_regnum (gdbarch
, M68K_SP_REGNUM
);
1051 set_gdbarch_pc_regnum (gdbarch
, M68K_PC_REGNUM
);
1052 set_gdbarch_ps_regnum (gdbarch
, M68K_PS_REGNUM
);
1053 set_gdbarch_fp0_regnum (gdbarch
, M68K_FP0_REGNUM
);
1055 set_gdbarch_push_dummy_call (gdbarch
, m68k_push_dummy_call
);
1056 set_gdbarch_return_value (gdbarch
, m68k_return_value
);
1059 set_gdbarch_print_insn (gdbarch
, print_insn_m68k
);
1061 #if defined JB_PC && defined JB_ELEMENT_SIZE
1062 tdep
->jb_pc
= JB_PC
;
1063 tdep
->jb_elt_size
= JB_ELEMENT_SIZE
;
1067 tdep
->struct_value_regnum
= M68K_A1_REGNUM
;
1068 tdep
->struct_return
= reg_struct_return
;
1070 /* Frame unwinder. */
1071 set_gdbarch_unwind_dummy_id (gdbarch
, m68k_unwind_dummy_id
);
1072 set_gdbarch_unwind_pc (gdbarch
, m68k_unwind_pc
);
1074 /* Hook in the DWARF CFI frame unwinder. */
1075 frame_unwind_append_sniffer (gdbarch
, dwarf2_frame_sniffer
);
1077 frame_base_set_default (gdbarch
, &m68k_frame_base
);
1079 /* Hook in ABI-specific overrides, if they have been registered. */
1080 gdbarch_init_osabi (info
, gdbarch
);
1082 /* Now we have tuned the configuration, set a few final things,
1083 based on what the OS ABI has told us. */
1085 if (tdep
->jb_pc
>= 0)
1086 set_gdbarch_get_longjmp_target (gdbarch
, m68k_get_longjmp_target
);
1088 frame_unwind_append_sniffer (gdbarch
, m68k_frame_sniffer
);
1095 m68k_dump_tdep (struct gdbarch
*current_gdbarch
, struct ui_file
*file
)
1097 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
1103 extern initialize_file_ftype _initialize_m68k_tdep
; /* -Wmissing-prototypes */
1106 _initialize_m68k_tdep (void)
1108 gdbarch_register (bfd_arch_m68k
, m68k_gdbarch_init
, m68k_dump_tdep
);