1 /* Target-dependent code for the MIPS architecture, for GDB, the GNU Debugger.
2 Copyright 1988, 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
3 Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
4 and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
33 #include "opcode/mips.h"
35 #define VM_MIN_ADDRESS (unsigned)0x400000
37 static int mips_in_lenient_prologue
PARAMS ((CORE_ADDR
, CORE_ADDR
));
39 /* Some MIPS boards don't support floating point, so we permit the
40 user to turn it off. */
43 /* Heuristic_proc_start may hunt through the text section for a long
44 time across a 2400 baud serial line. Allows the user to limit this
46 static unsigned int heuristic_fence_post
= 0;
48 #define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */
49 #define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */
50 #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset)
51 #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg)
52 #define PROC_REG_MASK(proc) ((proc)->pdr.regmask)
53 #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask)
54 #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset)
55 #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset)
56 #define PROC_PC_REG(proc) ((proc)->pdr.pcreg)
57 #define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym)
58 #define _PROC_MAGIC_ 0x0F0F0F0F
59 #define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_)
60 #define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_)
62 struct linked_proc_info
64 struct mips_extra_func_info info
;
65 struct linked_proc_info
*next
;
66 } *linked_proc_desc_table
= NULL
;
69 #define READ_FRAME_REG(fi, regno) read_next_frame_reg((fi)->next, regno)
72 read_next_frame_reg(fi
, regno
)
76 /* If it is the frame for sigtramp we have a complete sigcontext
77 immediately below the frame and we get the saved registers from there.
78 If the stack layout for sigtramp changes we might have to change these
79 constants and the companion fixup_sigtramp in mipsread.c */
81 #define SIGFRAME_BASE 0x12c /* sizeof(sigcontext) */
82 #define SIGFRAME_PC_OFF (-SIGFRAME_BASE + 2 * 4)
83 #define SIGFRAME_REGSAVE_OFF (-SIGFRAME_BASE + 3 * 4)
85 for (; fi
; fi
= fi
->next
)
86 if (in_sigtramp(fi
->pc
, 0)) {
88 if (regno
== PC_REGNUM
) offset
= SIGFRAME_PC_OFF
;
89 else if (regno
< 32) offset
= SIGFRAME_REGSAVE_OFF
+ regno
* 4;
91 return read_memory_integer(fi
->frame
+ offset
, 4);
93 else if (regno
== SP_REGNUM
) return fi
->frame
;
94 else if (fi
->saved_regs
->regs
[regno
])
95 return read_memory_integer(fi
->saved_regs
->regs
[regno
], 4);
96 return read_register(regno
);
100 mips_frame_saved_pc(frame
)
103 mips_extra_func_info_t proc_desc
= frame
->proc_desc
;
104 int pcreg
= proc_desc
? PROC_PC_REG(proc_desc
) : RA_REGNUM
;
106 if (proc_desc
&& PROC_DESC_IS_DUMMY(proc_desc
))
107 return read_memory_integer(frame
->frame
- 4, 4);
109 return read_next_frame_reg(frame
, pcreg
);
112 static struct mips_extra_func_info temp_proc_desc
;
113 static struct frame_saved_regs temp_saved_regs
;
115 /* This fencepost looks highly suspicious to me. Removing it also
116 seems suspicious as it could affect remote debugging across serial
120 heuristic_proc_start(pc
)
123 CORE_ADDR start_pc
= pc
;
124 CORE_ADDR fence
= start_pc
- heuristic_fence_post
;
126 if (start_pc
== 0) return 0;
128 if (heuristic_fence_post
== UINT_MAX
129 || fence
< VM_MIN_ADDRESS
)
130 fence
= VM_MIN_ADDRESS
;
132 /* search back for previous return */
133 for (start_pc
-= 4; ; start_pc
-= 4)
134 if (start_pc
< fence
)
136 /* It's not clear to me why we reach this point when
137 stop_soon_quietly, but with this test, at least we
138 don't print out warnings for every child forked (eg, on
139 decstation). 22apr93 rich@cygnus.com. */
140 if (!stop_soon_quietly
)
142 static int blurb_printed
= 0;
144 if (fence
== VM_MIN_ADDRESS
)
145 warning("Hit beginning of text section without finding");
147 warning("Hit heuristic-fence-post without finding");
149 warning("enclosing function for address 0x%x", pc
);
153 This warning occurs if you are debugging a function without any symbols\n\
154 (for example, in a stripped executable). In that case, you may wish to\n\
155 increase the size of the search with the `set heuristic-fence-post' command.\n\
157 Otherwise, you told GDB there was a function where there isn't one, or\n\
158 (more likely) you have encountered a bug in GDB.\n");
165 else if (ABOUT_TO_RETURN(start_pc
))
168 start_pc
+= 8; /* skip return, and its delay slot */
170 /* skip nops (usually 1) 0 - is this */
171 while (start_pc
< pc
&& read_memory_integer (start_pc
, 4) == 0)
177 static mips_extra_func_info_t
178 heuristic_proc_desc(start_pc
, limit_pc
, next_frame
)
179 CORE_ADDR start_pc
, limit_pc
;
182 CORE_ADDR sp
= next_frame
? next_frame
->frame
: read_register (SP_REGNUM
);
185 int has_frame_reg
= 0;
186 int reg30
; /* Value of $r30. Used by gcc for frame-pointer */
187 unsigned long reg_mask
= 0;
189 if (start_pc
== 0) return NULL
;
190 memset(&temp_proc_desc
, '\0', sizeof(temp_proc_desc
));
191 memset(&temp_saved_regs
, '\0', sizeof(struct frame_saved_regs
));
192 PROC_LOW_ADDR(&temp_proc_desc
) = start_pc
;
194 if (start_pc
+ 200 < limit_pc
) limit_pc
= start_pc
+ 200;
197 for (cur_pc
= start_pc
; cur_pc
< limit_pc
; cur_pc
+= 4) {
202 status
= read_memory_nobpt (cur_pc
, buf
, 4);
203 if (status
) memory_error (status
, cur_pc
);
204 word
= extract_unsigned_integer (buf
, 4);
206 if ((word
& 0xFFFF0000) == 0x27bd0000) /* addiu $sp,$sp,-i */
207 frame_size
+= (-word
) & 0xFFFF;
208 else if ((word
& 0xFFFF0000) == 0x23bd0000) /* addu $sp,$sp,-i */
209 frame_size
+= (-word
) & 0xFFFF;
210 else if ((word
& 0xFFE00000) == 0xafa00000) { /* sw reg,offset($sp) */
211 int reg
= (word
& 0x001F0000) >> 16;
212 reg_mask
|= 1 << reg
;
213 temp_saved_regs
.regs
[reg
] = sp
+ (short)word
;
215 else if ((word
& 0xFFFF0000) == 0x27be0000) { /* addiu $30,$sp,size */
216 if ((unsigned short)word
!= frame_size
)
217 reg30
= sp
+ (unsigned short)word
;
218 else if (!has_frame_reg
) {
221 reg30
= read_next_frame_reg(next_frame
, 30);
222 alloca_adjust
= reg30
- (sp
+ (unsigned short)word
);
223 if (alloca_adjust
> 0) {
224 /* FP > SP + frame_size. This may be because
225 /* of an alloca or somethings similar.
226 * Fix sp to "pre-alloca" value, and try again.
233 else if ((word
& 0xFFE00000) == 0xafc00000) { /* sw reg,offset($30) */
234 int reg
= (word
& 0x001F0000) >> 16;
235 reg_mask
|= 1 << reg
;
236 temp_saved_regs
.regs
[reg
] = reg30
+ (short)word
;
240 PROC_FRAME_REG(&temp_proc_desc
) = 30;
241 PROC_FRAME_OFFSET(&temp_proc_desc
) = 0;
244 PROC_FRAME_REG(&temp_proc_desc
) = SP_REGNUM
;
245 PROC_FRAME_OFFSET(&temp_proc_desc
) = frame_size
;
247 PROC_REG_MASK(&temp_proc_desc
) = reg_mask
;
248 PROC_PC_REG(&temp_proc_desc
) = RA_REGNUM
;
249 return &temp_proc_desc
;
252 static mips_extra_func_info_t
253 find_proc_desc(pc
, next_frame
)
257 mips_extra_func_info_t proc_desc
;
258 struct block
*b
= block_for_pc(pc
);
262 find_pc_partial_function (pc
, NULL
, &startaddr
, NULL
);
267 if (startaddr
> BLOCK_START (b
))
268 /* This is the "pathological" case referred to in a comment in
269 print_frame_info. It might be better to move this check into
273 sym
= lookup_symbol (MIPS_EFI_SYMBOL_NAME
, b
, LABEL_NAMESPACE
,
279 /* IF this is the topmost frame AND
280 * (this proc does not have debugging information OR
281 * the PC is in the procedure prologue)
282 * THEN create a "heuristic" proc_desc (by analyzing
283 * the actual code) to replace the "official" proc_desc.
285 proc_desc
= (mips_extra_func_info_t
)SYMBOL_VALUE(sym
);
286 if (next_frame
== NULL
) {
287 struct symtab_and_line val
;
288 struct symbol
*proc_symbol
=
289 PROC_DESC_IS_DUMMY(proc_desc
) ? 0 : PROC_SYMBOL(proc_desc
);
292 val
= find_pc_line (BLOCK_START
293 (SYMBOL_BLOCK_VALUE(proc_symbol
)),
295 val
.pc
= val
.end
? val
.end
: pc
;
297 if (!proc_symbol
|| pc
< val
.pc
) {
298 mips_extra_func_info_t found_heuristic
=
299 heuristic_proc_desc(PROC_LOW_ADDR(proc_desc
),
301 if (found_heuristic
) proc_desc
= found_heuristic
;
307 /* Is linked_proc_desc_table really necessary? It only seems to be used
308 by procedure call dummys. However, the procedures being called ought
309 to have their own proc_descs, and even if they don't,
310 heuristic_proc_desc knows how to create them! */
312 register struct linked_proc_info
*link
;
313 for (link
= linked_proc_desc_table
; link
; link
= link
->next
)
314 if (PROC_LOW_ADDR(&link
->info
) <= pc
315 && PROC_HIGH_ADDR(&link
->info
) > pc
)
319 startaddr
= heuristic_proc_start (pc
);
322 heuristic_proc_desc (startaddr
, pc
, next_frame
);
327 mips_extra_func_info_t cached_proc_desc
;
330 mips_frame_chain(frame
)
333 mips_extra_func_info_t proc_desc
;
334 CORE_ADDR saved_pc
= FRAME_SAVED_PC(frame
);
336 if (saved_pc
== 0 || inside_entry_file (saved_pc
))
339 proc_desc
= find_proc_desc(saved_pc
, frame
);
343 cached_proc_desc
= proc_desc
;
344 /* If frame size is zero, we must be at end of stack (or otherwise hosed).
345 If we don't check frame size, we loop forever if we see it == 0. */
346 if (PROC_FRAME_OFFSET (proc_desc
) == 0)
349 return read_next_frame_reg(frame
, PROC_FRAME_REG(proc_desc
))
350 + PROC_FRAME_OFFSET(proc_desc
);
354 init_extra_frame_info(fci
)
355 struct frame_info
*fci
;
357 extern struct obstack frame_cache_obstack
;
358 /* Use proc_desc calculated in frame_chain */
359 mips_extra_func_info_t proc_desc
=
360 fci
->next
? cached_proc_desc
: find_proc_desc(fci
->pc
, fci
->next
);
362 fci
->saved_regs
= (struct frame_saved_regs
*)
363 obstack_alloc (&frame_cache_obstack
, sizeof(struct frame_saved_regs
));
364 memset (fci
->saved_regs
, 0, sizeof (struct frame_saved_regs
));
366 proc_desc
== &temp_proc_desc
? 0 : proc_desc
;
370 CORE_ADDR reg_position
;
372 /* r0 bit means kernel trap */
373 int kernel_trap
= PROC_REG_MASK(proc_desc
) & 1;
375 /* Fixup frame-pointer - only needed for top frame */
376 /* This may not be quite right, if proc has a real frame register */
377 if (fci
->pc
== PROC_LOW_ADDR(proc_desc
) && !PROC_DESC_IS_DUMMY(proc_desc
))
378 fci
->frame
= read_register (SP_REGNUM
);
380 fci
->frame
= READ_FRAME_REG(fci
, PROC_FRAME_REG(proc_desc
))
381 + PROC_FRAME_OFFSET(proc_desc
);
383 /* If this is the innermost frame, and we are still in the
384 prologue (loosely defined), then the registers may not have
386 if (fci
->next
== NULL
387 && !PROC_DESC_IS_DUMMY(proc_desc
)
388 && mips_in_lenient_prologue (PROC_LOW_ADDR (proc_desc
), fci
->pc
))
390 /* Can't just say that the registers are not saved, because they
391 might get clobbered halfway through the prologue.
392 heuristic_proc_desc already has the right code to figure out
393 exactly what has been saved, so use it. As far as I know we
394 could be doing this (as we do on the 68k, for example)
395 regardless of whether we are in the prologue; I'm leaving in
396 the check for being in the prologue only out of conservatism
397 (I'm not sure whether heuristic_proc_desc handles all cases,
400 This stuff is ugly (and getting uglier by the minute). Probably
401 the best way to clean it up is to ignore the proc_desc's from
402 the symbols altogher, and get all the information we need by
403 examining the prologue (provided we can make the prologue
404 examining code good enough to get all the cases...). */
406 heuristic_proc_desc (PROC_LOW_ADDR (proc_desc
),
411 if (proc_desc
== &temp_proc_desc
)
412 *fci
->saved_regs
= temp_saved_regs
;
415 /* find which general-purpose registers were saved */
416 reg_position
= fci
->frame
+ PROC_REG_OFFSET(proc_desc
);
417 mask
= kernel_trap
? 0xFFFFFFFF : PROC_REG_MASK(proc_desc
);
418 for (ireg
= 31; mask
; --ireg
, mask
<<= 1)
419 if (mask
& 0x80000000)
421 fci
->saved_regs
->regs
[ireg
] = reg_position
;
424 /* find which floating-point registers were saved */
425 reg_position
= fci
->frame
+ PROC_FREG_OFFSET(proc_desc
);
427 /* The freg_offset points to where the first *double* register
428 is saved. So skip to the high-order word. */
430 mask
= kernel_trap
? 0xFFFFFFFF : PROC_FREG_MASK(proc_desc
);
431 for (ireg
= 31; mask
; --ireg
, mask
<<= 1)
432 if (mask
& 0x80000000)
434 fci
->saved_regs
->regs
[FP0_REGNUM
+ireg
] = reg_position
;
439 /* hack: if argument regs are saved, guess these contain args */
440 if ((PROC_REG_MASK(proc_desc
) & 0xF0) == 0) fci
->num_args
= -1;
441 else if ((PROC_REG_MASK(proc_desc
) & 0x80) == 0) fci
->num_args
= 4;
442 else if ((PROC_REG_MASK(proc_desc
) & 0x40) == 0) fci
->num_args
= 3;
443 else if ((PROC_REG_MASK(proc_desc
) & 0x20) == 0) fci
->num_args
= 2;
444 else if ((PROC_REG_MASK(proc_desc
) & 0x10) == 0) fci
->num_args
= 1;
446 fci
->saved_regs
->regs
[PC_REGNUM
] = fci
->saved_regs
->regs
[RA_REGNUM
];
450 /* MIPS stack frames are almost impenetrable. When execution stops,
451 we basically have to look at symbol information for the function
452 that we stopped in, which tells us *which* register (if any) is
453 the base of the frame pointer, and what offset from that register
454 the frame itself is at.
456 This presents a problem when trying to examine a stack in memory
457 (that isn't executing at the moment), using the "frame" command. We
458 don't have a PC, nor do we have any registers except SP.
460 This routine takes two arguments, SP and PC, and tries to make the
461 cached frames look as if these two arguments defined a frame on the
462 cache. This allows the rest of info frame to extract the important
463 arguments without difficulty. */
466 setup_arbitrary_frame (argc
, argv
)
471 error ("MIPS frame specifications require two arguments: sp and pc");
473 return create_new_frame (argv
[0], argv
[1]);
478 mips_push_arguments(nargs
, args
, sp
, struct_return
, struct_addr
)
483 CORE_ADDR struct_addr
;
487 int accumulate_size
= struct_return
? 4 : 0;
488 struct mips_arg
{ char *contents
; int len
; int offset
; };
489 struct mips_arg
*mips_args
=
490 (struct mips_arg
*)alloca(nargs
* sizeof(struct mips_arg
));
491 register struct mips_arg
*m_arg
;
492 for (i
= 0, m_arg
= mips_args
; i
< nargs
; i
++, m_arg
++) {
493 extern value
value_arg_coerce();
494 value arg
= value_arg_coerce (args
[i
]);
495 m_arg
->len
= TYPE_LENGTH (VALUE_TYPE (arg
));
496 /* This entire mips-specific routine is because doubles must be aligned
497 * on 8-byte boundaries. It still isn't quite right, because MIPS decided
498 * to align 'struct {int a, b}' on 4-byte boundaries (even though this
499 * breaks their varargs implementation...). A correct solution
500 * requires an simulation of gcc's 'alignof' (and use of 'alignof'
501 * in stdarg.h/varargs.h).
503 if (m_arg
->len
> 4) accumulate_size
= (accumulate_size
+ 7) & -8;
504 m_arg
->offset
= accumulate_size
;
505 accumulate_size
= (accumulate_size
+ m_arg
->len
+ 3) & -4;
506 m_arg
->contents
= VALUE_CONTENTS(arg
);
508 accumulate_size
= (accumulate_size
+ 7) & (-8);
509 if (accumulate_size
< 16) accumulate_size
= 16;
510 sp
-= accumulate_size
;
511 for (i
= nargs
; m_arg
--, --i
>= 0; )
512 write_memory(sp
+ m_arg
->offset
, m_arg
->contents
, m_arg
->len
);
515 write_memory(sp
, (char *)&buf
, sizeof(CORE_ADDR
));
520 /* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */
521 #define MASK(i,j) ((1 << (j)+1)-1 ^ (1 << (i))-1)
524 mips_push_dummy_frame()
527 struct linked_proc_info
*link
= (struct linked_proc_info
*)
528 xmalloc(sizeof(struct linked_proc_info
));
529 mips_extra_func_info_t proc_desc
= &link
->info
;
530 CORE_ADDR sp
= read_register (SP_REGNUM
);
531 CORE_ADDR save_address
;
532 REGISTER_TYPE buffer
;
533 link
->next
= linked_proc_desc_table
;
534 linked_proc_desc_table
= link
;
535 #define PUSH_FP_REGNUM 16 /* must be a register preserved across calls */
536 #define GEN_REG_SAVE_MASK MASK(1,16)|MASK(24,28)|(1<<31)
537 #define GEN_REG_SAVE_COUNT 22
538 #define FLOAT_REG_SAVE_MASK MASK(0,19)
539 #define FLOAT_REG_SAVE_COUNT 20
540 #define SPECIAL_REG_SAVE_COUNT 4
542 * The registers we must save are all those not preserved across
543 * procedure calls. Dest_Reg (see tm-mips.h) must also be saved.
544 * In addition, we must save the PC, and PUSH_FP_REGNUM.
545 * (Ideally, we should also save MDLO/-HI and FP Control/Status reg.)
547 * Dummy frame layout:
550 * Saved MMHI, MMLO, FPC_CSR
555 * Saved D18 (i.e. F19, F18)
557 * Saved D0 (i.e. F1, F0)
558 * CALL_DUMMY (subroutine stub; see tm-mips.h)
559 * Parameter build area (not yet implemented)
562 PROC_REG_MASK(proc_desc
) = GEN_REG_SAVE_MASK
;
563 PROC_FREG_MASK(proc_desc
) = mips_fpu
? FLOAT_REG_SAVE_MASK
: 0;
564 PROC_REG_OFFSET(proc_desc
) = /* offset of (Saved R31) from FP */
565 -sizeof(long) - 4 * SPECIAL_REG_SAVE_COUNT
;
566 PROC_FREG_OFFSET(proc_desc
) = /* offset of (Saved D18) from FP */
567 -sizeof(double) - 4 * (SPECIAL_REG_SAVE_COUNT
+ GEN_REG_SAVE_COUNT
);
568 /* save general registers */
569 save_address
= sp
+ PROC_REG_OFFSET(proc_desc
);
570 for (ireg
= 32; --ireg
>= 0; )
571 if (PROC_REG_MASK(proc_desc
) & (1 << ireg
))
573 buffer
= read_register (ireg
);
574 write_memory (save_address
, (char *)&buffer
, sizeof(REGISTER_TYPE
));
577 /* save floating-points registers starting with high order word */
578 save_address
= sp
+ PROC_FREG_OFFSET(proc_desc
) + 4;
579 for (ireg
= 32; --ireg
>= 0; )
580 if (PROC_FREG_MASK(proc_desc
) & (1 << ireg
))
582 buffer
= read_register (ireg
+ FP0_REGNUM
);
583 write_memory (save_address
, (char *)&buffer
, 4);
586 write_register (PUSH_FP_REGNUM
, sp
);
587 PROC_FRAME_REG(proc_desc
) = PUSH_FP_REGNUM
;
588 PROC_FRAME_OFFSET(proc_desc
) = 0;
589 buffer
= read_register (PC_REGNUM
);
590 write_memory (sp
- 4, (char *)&buffer
, sizeof(REGISTER_TYPE
));
591 buffer
= read_register (HI_REGNUM
);
592 write_memory (sp
- 8, (char *)&buffer
, sizeof(REGISTER_TYPE
));
593 buffer
= read_register (LO_REGNUM
);
594 write_memory (sp
- 12, (char *)&buffer
, sizeof(REGISTER_TYPE
));
595 buffer
= read_register (mips_fpu
? FCRCS_REGNUM
: ZERO_REGNUM
);
596 write_memory (sp
- 16, (char *)&buffer
, sizeof(REGISTER_TYPE
));
597 sp
-= 4 * (GEN_REG_SAVE_COUNT
598 + (mips_fpu
? FLOAT_REG_SAVE_COUNT
: 0)
599 + SPECIAL_REG_SAVE_COUNT
);
600 write_register (SP_REGNUM
, sp
);
601 PROC_LOW_ADDR(proc_desc
) = sp
- CALL_DUMMY_SIZE
+ CALL_DUMMY_START_OFFSET
;
602 PROC_HIGH_ADDR(proc_desc
) = sp
;
603 SET_PROC_DESC_IS_DUMMY(proc_desc
);
604 PROC_PC_REG(proc_desc
) = RA_REGNUM
;
611 FRAME frame
= get_current_frame ();
612 CORE_ADDR new_sp
= frame
->frame
;
614 mips_extra_func_info_t proc_desc
= frame
->proc_desc
;
616 write_register (PC_REGNUM
, FRAME_SAVED_PC(frame
));
619 for (regnum
= 32; --regnum
>= 0; )
620 if (PROC_REG_MASK(proc_desc
) & (1 << regnum
))
621 write_register (regnum
,
622 read_memory_integer (frame
->saved_regs
->regs
[regnum
],
624 for (regnum
= 32; --regnum
>= 0; )
625 if (PROC_FREG_MASK(proc_desc
) & (1 << regnum
))
626 write_register (regnum
+ FP0_REGNUM
,
627 read_memory_integer (frame
->saved_regs
->regs
[regnum
+ FP0_REGNUM
], 4));
629 write_register (SP_REGNUM
, new_sp
);
630 flush_cached_frames ();
631 /* We let mips_init_extra_frame_info figure out the frame pointer */
632 set_current_frame (create_new_frame (0, read_pc ()));
634 if (PROC_DESC_IS_DUMMY(proc_desc
))
636 struct linked_proc_info
*pi_ptr
, *prev_ptr
;
638 for (pi_ptr
= linked_proc_desc_table
, prev_ptr
= NULL
;
640 prev_ptr
= pi_ptr
, pi_ptr
= pi_ptr
->next
)
642 if (&pi_ptr
->info
== proc_desc
)
647 error ("Can't locate dummy extra frame info\n");
649 if (prev_ptr
!= NULL
)
650 prev_ptr
->next
= pi_ptr
->next
;
652 linked_proc_desc_table
= pi_ptr
->next
;
656 write_register (HI_REGNUM
, read_memory_integer(new_sp
- 8, 4));
657 write_register (LO_REGNUM
, read_memory_integer(new_sp
- 12, 4));
659 write_register (FCRCS_REGNUM
, read_memory_integer(new_sp
- 16, 4));
664 mips_print_register (regnum
, all
)
667 unsigned char raw_buffer
[MAX_REGISTER_RAW_SIZE
];
670 /* Get the data in raw format. */
671 if (read_relative_register_raw_bytes (regnum
, raw_buffer
))
673 printf_filtered ("%s: [Invalid]", reg_names
[regnum
]);
677 /* If an even floating pointer register, also print as double. */
678 if (regnum
>= FP0_REGNUM
&& regnum
< FP0_REGNUM
+32
679 && !((regnum
-FP0_REGNUM
) & 1)) {
680 char dbuffer
[MAX_REGISTER_RAW_SIZE
];
682 read_relative_register_raw_bytes (regnum
, dbuffer
);
683 read_relative_register_raw_bytes (regnum
+1, dbuffer
+4);
684 #ifdef REGISTER_CONVERT_TO_TYPE
685 REGISTER_CONVERT_TO_TYPE(regnum
, builtin_type_double
, dbuffer
);
687 printf_filtered ("(d%d: ", regnum
-FP0_REGNUM
);
688 val_print (builtin_type_double
, dbuffer
, 0,
689 stdout
, 0, 1, 0, Val_pretty_default
);
690 printf_filtered ("); ");
692 fputs_filtered (reg_names
[regnum
], stdout
);
694 /* The problem with printing numeric register names (r26, etc.) is that
695 the user can't use them on input. Probably the best solution is to
696 fix it so that either the numeric or the funky (a2, etc.) names
697 are accepted on input. */
699 printf_filtered ("(r%d): ", regnum
);
701 printf_filtered (": ");
703 /* If virtual format is floating, print it that way. */
704 if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (regnum
)) == TYPE_CODE_FLT
705 && ! INVALID_FLOAT (raw_buffer
, REGISTER_VIRTUAL_SIZE(regnum
))) {
706 val_print (REGISTER_VIRTUAL_TYPE (regnum
), raw_buffer
, 0,
707 stdout
, 0, 1, 0, Val_pretty_default
);
709 /* Else print as integer in hex. */
714 val
= extract_signed_integer (raw_buffer
,
715 REGISTER_RAW_SIZE (regnum
));
718 printf_filtered ("0");
720 /* FIXME: We should be printing this in a fixed field width, so that
721 registers line up. */
722 printf_filtered (local_hex_format(), val
);
724 printf_filtered ("%s=%d", local_hex_string(val
), val
);
728 /* Replacement for generic do_registers_info. */
730 mips_do_registers_info (regnum
, fpregs
)
735 mips_print_register (regnum
, 0);
736 printf_filtered ("\n");
739 for (regnum
= 0; regnum
< NUM_REGS
; ) {
740 if ((!fpregs
) && regnum
>= FP0_REGNUM
&& regnum
<= FCRIR_REGNUM
) {
744 mips_print_register (regnum
, 1);
746 if ((regnum
& 3) == 0 || regnum
== NUM_REGS
)
747 printf_filtered (";\n");
749 printf_filtered ("; ");
753 /* Return number of args passed to a frame. described by FIP.
754 Can return -1, meaning no way to tell. */
757 mips_frame_num_args(fip
)
761 struct chain_info_t
*p
;
763 p
= mips_find_cached_frame(FRAME_FP(fip
));
765 return p
->the_info
.numargs
;
770 /* Is this a branch with a delay slot? */
776 for (i
= 0; i
< NUMOPCODES
; ++i
)
777 if (mips_opcodes
[i
].pinfo
!= INSN_MACRO
778 && (insn
& mips_opcodes
[i
].mask
) == mips_opcodes
[i
].match
)
780 return (i
< NUMOPCODES
781 && (mips_opcodes
[i
].pinfo
& (INSN_UNCOND_BRANCH_DELAY
782 | INSN_COND_BRANCH_DELAY
783 | INSN_COND_BRANCH_LIKELY
)));
786 /* To skip prologues, I use this predicate. Returns either PC itself
787 if the code at PC does not look like a function prologue; otherwise
788 returns an address that (if we're lucky) follows the prologue. If
789 LENIENT, then we must skip everything which is involved in setting
790 up the frame (it's OK to skip more, just so long as we don't skip
791 anything which might clobber the registers which are being saved.
792 We must skip more in the case where part of the prologue is in the
793 delay slot of a non-prologue instruction). */
796 mips_skip_prologue (pc
, lenient
)
804 int seen_sp_adjust
= 0;
806 /* Skip the typical prologue instructions. These are the stack adjustment
807 instruction and the instructions that save registers on the stack
808 or in the gcc frame. */
809 for (offset
= 0; offset
< 100; offset
+= 4)
814 status
= read_memory_nobpt (pc
+ offset
, buf
, 4);
816 memory_error (status
, pc
+ offset
);
817 inst
= extract_unsigned_integer (buf
, 4);
819 if (lenient
&& is_delayed (inst
))
822 if ((inst
& 0xffff0000) == 0x27bd0000) /* addiu $sp,$sp,offset */
824 else if ((inst
& 0xFFE00000) == 0xAFA00000 && (inst
& 0x001F0000))
825 continue; /* sw reg,n($sp) */
827 else if ((inst
& 0xFFE00000) == 0xE7A00000) /* swc1 freg,n($sp) */
829 else if ((inst
& 0xF3E00000) == 0xA3C00000 && (inst
& 0x001F0000))
831 continue; /* reg != $zero */
832 else if (inst
== 0x03A0F021) /* move $s8,$sp */
834 else if ((inst
& 0xFF9F07FF) == 0x00800021) /* move reg,$a0-$a3 */
841 /* FIXME schauer. The following code seems no longer necessary if we
842 always skip the typical prologue instructions. */
848 /* Well, it looks like a frameless. Let's make sure.
849 Note that we are not called on the current PC,
850 but on the function`s start PC, and I have definitely
851 seen optimized code that adjusts the SP quite later */
852 b
= block_for_pc(pc
);
855 f
= lookup_symbol(MIPS_EFI_SYMBOL_NAME
, b
, LABEL_NAMESPACE
, 0, NULL
);
857 /* Ideally, I would like to use the adjusted info
858 from mips_frame_info(), but for all practical
859 purposes it will not matter (and it would require
860 a different definition of SKIP_PROLOGUE())
862 Actually, it would not hurt to skip the storing
863 of arguments on the stack as well. */
864 if (((mips_extra_func_info_t
)SYMBOL_VALUE(f
))->pdr
.frameoffset
)
871 /* Is address PC in the prologue (loosely defined) for function at
875 mips_in_lenient_prologue (startaddr
, pc
)
879 CORE_ADDR end_prologue
= mips_skip_prologue (startaddr
, 1);
880 return pc
>= startaddr
&& pc
< end_prologue
;
883 /* Given a return value in `regbuf' with a type `valtype',
884 extract and copy its value into `valbuf'. */
886 mips_extract_return_value (valtype
, regbuf
, valbuf
)
887 struct type
*valtype
;
888 char regbuf
[REGISTER_BYTES
];
893 regnum
= TYPE_CODE (valtype
) == TYPE_CODE_FLT
&& mips_fpu
? FP0_REGNUM
: 2;
895 memcpy (valbuf
, regbuf
+ REGISTER_BYTE (regnum
), TYPE_LENGTH (valtype
));
896 #ifdef REGISTER_CONVERT_TO_TYPE
897 REGISTER_CONVERT_TO_TYPE(regnum
, valtype
, valbuf
);
901 /* Given a return value in `regbuf' with a type `valtype',
902 write it's value into the appropriate register. */
904 mips_store_return_value (valtype
, valbuf
)
905 struct type
*valtype
;
909 char raw_buffer
[MAX_REGISTER_RAW_SIZE
];
911 regnum
= TYPE_CODE (valtype
) == TYPE_CODE_FLT
&& mips_fpu
? FP0_REGNUM
: 2;
912 memcpy(raw_buffer
, valbuf
, TYPE_LENGTH (valtype
));
914 #ifdef REGISTER_CONVERT_FROM_TYPE
915 REGISTER_CONVERT_FROM_TYPE(regnum
, valtype
, raw_buffer
);
918 write_register_bytes(REGISTER_BYTE (regnum
), raw_buffer
, TYPE_LENGTH (valtype
));
921 static void reinit_frame_cache_sfunc
PARAMS ((char *, int
922 struct cmd_list_element
*));
924 /* Just like reinit_frame_cache, but with the right arguments to be
925 callable as an sfunc. */
927 reinit_frame_cache_sfunc (args
, from_tty
, c
)
930 struct cmd_list_element
*c
;
932 reinit_frame_cache ();
936 _initialize_mips_tdep ()
938 struct cmd_list_element
*c
;
940 /* Let the user turn off floating point and set the fence post for
941 heuristic_proc_start. */
944 (add_set_cmd ("mipsfpu", class_support
, var_boolean
,
946 "Set use of floating point coprocessor.\n\
947 Turn off to avoid using floating point instructions when calling functions\n\
948 or dealing with return values.", &setlist
),
951 /* We really would like to have both "0" and "unlimited" work, but
952 command.c doesn't deal with that. So make it a var_zinteger
953 because the user can always use "999999" or some such for unlimited. */
954 c
= add_set_cmd ("heuristic-fence-post", class_support
, var_zinteger
,
955 (char *) &heuristic_fence_post
,
957 Set the distance searched for the start of a function.\n\
958 If you are debugging a stripped executable, GDB needs to search through the\n\
959 program for the start of a function. This command sets the distance of the\n\
960 search. The only need to set it is when debugging a stripped executable.",
962 /* We need to throw away the frame cache when we set this, since it
963 might change our ability to get backtraces. */
964 c
->function
.sfunc
= reinit_frame_cache_sfunc
;
965 add_show_from_set (c
, &showlist
);