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
;
345 /* If no frame pointer and frame size is zero, we must be at end
346 of stack (or otherwise hosed). If we don't check frame size,
347 we loop forever if we see a zero size frame. */
348 if (PROC_FRAME_REG (proc_desc
) == SP_REGNUM
349 && PROC_FRAME_OFFSET (proc_desc
) == 0
350 /* Frameless functions, which can happen on the innermost frame
351 or a frame which was innermost when a signal happened, can
352 have frame size zero. No need to check for non-frameless
353 functions in these situations, though (I don't think). */
354 && frame
->next
!= NULL
355 && !frame
->next
->signal_handler_caller
)
358 return read_next_frame_reg(frame
, PROC_FRAME_REG(proc_desc
))
359 + PROC_FRAME_OFFSET(proc_desc
);
363 init_extra_frame_info(fci
)
364 struct frame_info
*fci
;
366 extern struct obstack frame_cache_obstack
;
367 /* Use proc_desc calculated in frame_chain */
368 mips_extra_func_info_t proc_desc
=
369 fci
->next
? cached_proc_desc
: find_proc_desc(fci
->pc
, fci
->next
);
371 fci
->saved_regs
= (struct frame_saved_regs
*)
372 obstack_alloc (&frame_cache_obstack
, sizeof(struct frame_saved_regs
));
373 memset (fci
->saved_regs
, 0, sizeof (struct frame_saved_regs
));
375 proc_desc
== &temp_proc_desc
? 0 : proc_desc
;
379 CORE_ADDR reg_position
;
381 /* r0 bit means kernel trap */
382 int kernel_trap
= PROC_REG_MASK(proc_desc
) & 1;
384 /* Fixup frame-pointer - only needed for top frame */
385 /* This may not be quite right, if proc has a real frame register */
386 if (fci
->pc
== PROC_LOW_ADDR(proc_desc
) && !PROC_DESC_IS_DUMMY(proc_desc
))
387 fci
->frame
= read_register (SP_REGNUM
);
389 fci
->frame
= READ_FRAME_REG(fci
, PROC_FRAME_REG(proc_desc
))
390 + PROC_FRAME_OFFSET(proc_desc
);
392 /* If this is the innermost frame, and we are still in the
393 prologue (loosely defined), then the registers may not have
395 if (fci
->next
== NULL
396 && !PROC_DESC_IS_DUMMY(proc_desc
)
397 && mips_in_lenient_prologue (PROC_LOW_ADDR (proc_desc
), fci
->pc
))
399 /* Can't just say that the registers are not saved, because they
400 might get clobbered halfway through the prologue.
401 heuristic_proc_desc already has the right code to figure out
402 exactly what has been saved, so use it. As far as I know we
403 could be doing this (as we do on the 68k, for example)
404 regardless of whether we are in the prologue; I'm leaving in
405 the check for being in the prologue only out of conservatism
406 (I'm not sure whether heuristic_proc_desc handles all cases,
409 This stuff is ugly (and getting uglier by the minute). Probably
410 the best way to clean it up is to ignore the proc_desc's from
411 the symbols altogher, and get all the information we need by
412 examining the prologue (provided we can make the prologue
413 examining code good enough to get all the cases...). */
415 heuristic_proc_desc (PROC_LOW_ADDR (proc_desc
),
420 if (proc_desc
== &temp_proc_desc
)
421 *fci
->saved_regs
= temp_saved_regs
;
424 /* find which general-purpose registers were saved */
425 reg_position
= fci
->frame
+ PROC_REG_OFFSET(proc_desc
);
426 mask
= kernel_trap
? 0xFFFFFFFF : PROC_REG_MASK(proc_desc
);
427 for (ireg
= 31; mask
; --ireg
, mask
<<= 1)
428 if (mask
& 0x80000000)
430 fci
->saved_regs
->regs
[ireg
] = reg_position
;
433 /* find which floating-point registers were saved */
434 reg_position
= fci
->frame
+ PROC_FREG_OFFSET(proc_desc
);
436 /* The freg_offset points to where the first *double* register
437 is saved. So skip to the high-order word. */
439 mask
= kernel_trap
? 0xFFFFFFFF : PROC_FREG_MASK(proc_desc
);
440 for (ireg
= 31; mask
; --ireg
, mask
<<= 1)
441 if (mask
& 0x80000000)
443 fci
->saved_regs
->regs
[FP0_REGNUM
+ireg
] = reg_position
;
448 /* hack: if argument regs are saved, guess these contain args */
449 if ((PROC_REG_MASK(proc_desc
) & 0xF0) == 0) fci
->num_args
= -1;
450 else if ((PROC_REG_MASK(proc_desc
) & 0x80) == 0) fci
->num_args
= 4;
451 else if ((PROC_REG_MASK(proc_desc
) & 0x40) == 0) fci
->num_args
= 3;
452 else if ((PROC_REG_MASK(proc_desc
) & 0x20) == 0) fci
->num_args
= 2;
453 else if ((PROC_REG_MASK(proc_desc
) & 0x10) == 0) fci
->num_args
= 1;
455 fci
->saved_regs
->regs
[PC_REGNUM
] = fci
->saved_regs
->regs
[RA_REGNUM
];
459 /* MIPS stack frames are almost impenetrable. When execution stops,
460 we basically have to look at symbol information for the function
461 that we stopped in, which tells us *which* register (if any) is
462 the base of the frame pointer, and what offset from that register
463 the frame itself is at.
465 This presents a problem when trying to examine a stack in memory
466 (that isn't executing at the moment), using the "frame" command. We
467 don't have a PC, nor do we have any registers except SP.
469 This routine takes two arguments, SP and PC, and tries to make the
470 cached frames look as if these two arguments defined a frame on the
471 cache. This allows the rest of info frame to extract the important
472 arguments without difficulty. */
475 setup_arbitrary_frame (argc
, argv
)
480 error ("MIPS frame specifications require two arguments: sp and pc");
482 return create_new_frame (argv
[0], argv
[1]);
487 mips_push_arguments(nargs
, args
, sp
, struct_return
, struct_addr
)
492 CORE_ADDR struct_addr
;
496 int accumulate_size
= struct_return
? 4 : 0;
497 struct mips_arg
{ char *contents
; int len
; int offset
; };
498 struct mips_arg
*mips_args
=
499 (struct mips_arg
*)alloca(nargs
* sizeof(struct mips_arg
));
500 register struct mips_arg
*m_arg
;
501 for (i
= 0, m_arg
= mips_args
; i
< nargs
; i
++, m_arg
++) {
502 extern value
value_arg_coerce();
503 value arg
= value_arg_coerce (args
[i
]);
504 m_arg
->len
= TYPE_LENGTH (VALUE_TYPE (arg
));
505 /* This entire mips-specific routine is because doubles must be aligned
506 * on 8-byte boundaries. It still isn't quite right, because MIPS decided
507 * to align 'struct {int a, b}' on 4-byte boundaries (even though this
508 * breaks their varargs implementation...). A correct solution
509 * requires an simulation of gcc's 'alignof' (and use of 'alignof'
510 * in stdarg.h/varargs.h).
512 if (m_arg
->len
> 4) accumulate_size
= (accumulate_size
+ 7) & -8;
513 m_arg
->offset
= accumulate_size
;
514 accumulate_size
= (accumulate_size
+ m_arg
->len
+ 3) & -4;
515 m_arg
->contents
= VALUE_CONTENTS(arg
);
517 accumulate_size
= (accumulate_size
+ 7) & (-8);
518 if (accumulate_size
< 16) accumulate_size
= 16;
519 sp
-= accumulate_size
;
520 for (i
= nargs
; m_arg
--, --i
>= 0; )
521 write_memory(sp
+ m_arg
->offset
, m_arg
->contents
, m_arg
->len
);
524 write_memory(sp
, (char *)&buf
, sizeof(CORE_ADDR
));
529 /* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */
530 #define MASK(i,j) ((1 << (j)+1)-1 ^ (1 << (i))-1)
533 mips_push_dummy_frame()
536 struct linked_proc_info
*link
= (struct linked_proc_info
*)
537 xmalloc(sizeof(struct linked_proc_info
));
538 mips_extra_func_info_t proc_desc
= &link
->info
;
539 CORE_ADDR sp
= read_register (SP_REGNUM
);
540 CORE_ADDR save_address
;
541 REGISTER_TYPE buffer
;
542 link
->next
= linked_proc_desc_table
;
543 linked_proc_desc_table
= link
;
544 #define PUSH_FP_REGNUM 16 /* must be a register preserved across calls */
545 #define GEN_REG_SAVE_MASK MASK(1,16)|MASK(24,28)|(1<<31)
546 #define GEN_REG_SAVE_COUNT 22
547 #define FLOAT_REG_SAVE_MASK MASK(0,19)
548 #define FLOAT_REG_SAVE_COUNT 20
549 #define SPECIAL_REG_SAVE_COUNT 4
551 * The registers we must save are all those not preserved across
552 * procedure calls. Dest_Reg (see tm-mips.h) must also be saved.
553 * In addition, we must save the PC, and PUSH_FP_REGNUM.
554 * (Ideally, we should also save MDLO/-HI and FP Control/Status reg.)
556 * Dummy frame layout:
559 * Saved MMHI, MMLO, FPC_CSR
564 * Saved D18 (i.e. F19, F18)
566 * Saved D0 (i.e. F1, F0)
567 * CALL_DUMMY (subroutine stub; see tm-mips.h)
568 * Parameter build area (not yet implemented)
571 PROC_REG_MASK(proc_desc
) = GEN_REG_SAVE_MASK
;
572 PROC_FREG_MASK(proc_desc
) = mips_fpu
? FLOAT_REG_SAVE_MASK
: 0;
573 PROC_REG_OFFSET(proc_desc
) = /* offset of (Saved R31) from FP */
574 -sizeof(long) - 4 * SPECIAL_REG_SAVE_COUNT
;
575 PROC_FREG_OFFSET(proc_desc
) = /* offset of (Saved D18) from FP */
576 -sizeof(double) - 4 * (SPECIAL_REG_SAVE_COUNT
+ GEN_REG_SAVE_COUNT
);
577 /* save general registers */
578 save_address
= sp
+ PROC_REG_OFFSET(proc_desc
);
579 for (ireg
= 32; --ireg
>= 0; )
580 if (PROC_REG_MASK(proc_desc
) & (1 << ireg
))
582 buffer
= read_register (ireg
);
583 write_memory (save_address
, (char *)&buffer
, sizeof(REGISTER_TYPE
));
586 /* save floating-points registers starting with high order word */
587 save_address
= sp
+ PROC_FREG_OFFSET(proc_desc
) + 4;
588 for (ireg
= 32; --ireg
>= 0; )
589 if (PROC_FREG_MASK(proc_desc
) & (1 << ireg
))
591 buffer
= read_register (ireg
+ FP0_REGNUM
);
592 write_memory (save_address
, (char *)&buffer
, 4);
595 write_register (PUSH_FP_REGNUM
, sp
);
596 PROC_FRAME_REG(proc_desc
) = PUSH_FP_REGNUM
;
597 PROC_FRAME_OFFSET(proc_desc
) = 0;
598 buffer
= read_register (PC_REGNUM
);
599 write_memory (sp
- 4, (char *)&buffer
, sizeof(REGISTER_TYPE
));
600 buffer
= read_register (HI_REGNUM
);
601 write_memory (sp
- 8, (char *)&buffer
, sizeof(REGISTER_TYPE
));
602 buffer
= read_register (LO_REGNUM
);
603 write_memory (sp
- 12, (char *)&buffer
, sizeof(REGISTER_TYPE
));
604 buffer
= read_register (mips_fpu
? FCRCS_REGNUM
: ZERO_REGNUM
);
605 write_memory (sp
- 16, (char *)&buffer
, sizeof(REGISTER_TYPE
));
606 sp
-= 4 * (GEN_REG_SAVE_COUNT
607 + (mips_fpu
? FLOAT_REG_SAVE_COUNT
: 0)
608 + SPECIAL_REG_SAVE_COUNT
);
609 write_register (SP_REGNUM
, sp
);
610 PROC_LOW_ADDR(proc_desc
) = sp
- CALL_DUMMY_SIZE
+ CALL_DUMMY_START_OFFSET
;
611 PROC_HIGH_ADDR(proc_desc
) = sp
;
612 SET_PROC_DESC_IS_DUMMY(proc_desc
);
613 PROC_PC_REG(proc_desc
) = RA_REGNUM
;
620 FRAME frame
= get_current_frame ();
621 CORE_ADDR new_sp
= frame
->frame
;
623 mips_extra_func_info_t proc_desc
= frame
->proc_desc
;
625 write_register (PC_REGNUM
, FRAME_SAVED_PC(frame
));
628 for (regnum
= 32; --regnum
>= 0; )
629 if (PROC_REG_MASK(proc_desc
) & (1 << regnum
))
630 write_register (regnum
,
631 read_memory_integer (frame
->saved_regs
->regs
[regnum
],
633 for (regnum
= 32; --regnum
>= 0; )
634 if (PROC_FREG_MASK(proc_desc
) & (1 << regnum
))
635 write_register (regnum
+ FP0_REGNUM
,
636 read_memory_integer (frame
->saved_regs
->regs
[regnum
+ FP0_REGNUM
], 4));
638 write_register (SP_REGNUM
, new_sp
);
639 flush_cached_frames ();
640 /* We let mips_init_extra_frame_info figure out the frame pointer */
641 set_current_frame (create_new_frame (0, read_pc ()));
643 if (PROC_DESC_IS_DUMMY(proc_desc
))
645 struct linked_proc_info
*pi_ptr
, *prev_ptr
;
647 for (pi_ptr
= linked_proc_desc_table
, prev_ptr
= NULL
;
649 prev_ptr
= pi_ptr
, pi_ptr
= pi_ptr
->next
)
651 if (&pi_ptr
->info
== proc_desc
)
656 error ("Can't locate dummy extra frame info\n");
658 if (prev_ptr
!= NULL
)
659 prev_ptr
->next
= pi_ptr
->next
;
661 linked_proc_desc_table
= pi_ptr
->next
;
665 write_register (HI_REGNUM
, read_memory_integer(new_sp
- 8, 4));
666 write_register (LO_REGNUM
, read_memory_integer(new_sp
- 12, 4));
668 write_register (FCRCS_REGNUM
, read_memory_integer(new_sp
- 16, 4));
673 mips_print_register (regnum
, all
)
676 unsigned char raw_buffer
[MAX_REGISTER_RAW_SIZE
];
679 /* Get the data in raw format. */
680 if (read_relative_register_raw_bytes (regnum
, raw_buffer
))
682 printf_filtered ("%s: [Invalid]", reg_names
[regnum
]);
686 /* If an even floating pointer register, also print as double. */
687 if (regnum
>= FP0_REGNUM
&& regnum
< FP0_REGNUM
+32
688 && !((regnum
-FP0_REGNUM
) & 1)) {
689 char dbuffer
[MAX_REGISTER_RAW_SIZE
];
691 read_relative_register_raw_bytes (regnum
, dbuffer
);
692 read_relative_register_raw_bytes (regnum
+1, dbuffer
+4);
693 #ifdef REGISTER_CONVERT_TO_TYPE
694 REGISTER_CONVERT_TO_TYPE(regnum
, builtin_type_double
, dbuffer
);
696 printf_filtered ("(d%d: ", regnum
-FP0_REGNUM
);
697 val_print (builtin_type_double
, dbuffer
, 0,
698 stdout
, 0, 1, 0, Val_pretty_default
);
699 printf_filtered ("); ");
701 fputs_filtered (reg_names
[regnum
], stdout
);
703 /* The problem with printing numeric register names (r26, etc.) is that
704 the user can't use them on input. Probably the best solution is to
705 fix it so that either the numeric or the funky (a2, etc.) names
706 are accepted on input. */
708 printf_filtered ("(r%d): ", regnum
);
710 printf_filtered (": ");
712 /* If virtual format is floating, print it that way. */
713 if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (regnum
)) == TYPE_CODE_FLT
714 && ! INVALID_FLOAT (raw_buffer
, REGISTER_VIRTUAL_SIZE(regnum
))) {
715 val_print (REGISTER_VIRTUAL_TYPE (regnum
), raw_buffer
, 0,
716 stdout
, 0, 1, 0, Val_pretty_default
);
718 /* Else print as integer in hex. */
723 val
= extract_signed_integer (raw_buffer
,
724 REGISTER_RAW_SIZE (regnum
));
727 printf_filtered ("0");
729 /* FIXME: We should be printing this in a fixed field width, so that
730 registers line up. */
731 printf_filtered (local_hex_format(), val
);
733 printf_filtered ("%s=%d", local_hex_string(val
), val
);
737 /* Replacement for generic do_registers_info. */
739 mips_do_registers_info (regnum
, fpregs
)
744 mips_print_register (regnum
, 0);
745 printf_filtered ("\n");
748 for (regnum
= 0; regnum
< NUM_REGS
; ) {
749 if ((!fpregs
) && regnum
>= FP0_REGNUM
&& regnum
<= FCRIR_REGNUM
) {
753 mips_print_register (regnum
, 1);
755 if ((regnum
& 3) == 0 || regnum
== NUM_REGS
)
756 printf_filtered (";\n");
758 printf_filtered ("; ");
762 /* Return number of args passed to a frame. described by FIP.
763 Can return -1, meaning no way to tell. */
766 mips_frame_num_args(fip
)
770 struct chain_info_t
*p
;
772 p
= mips_find_cached_frame(FRAME_FP(fip
));
774 return p
->the_info
.numargs
;
779 /* Is this a branch with a delay slot? */
785 for (i
= 0; i
< NUMOPCODES
; ++i
)
786 if (mips_opcodes
[i
].pinfo
!= INSN_MACRO
787 && (insn
& mips_opcodes
[i
].mask
) == mips_opcodes
[i
].match
)
789 return (i
< NUMOPCODES
790 && (mips_opcodes
[i
].pinfo
& (INSN_UNCOND_BRANCH_DELAY
791 | INSN_COND_BRANCH_DELAY
792 | INSN_COND_BRANCH_LIKELY
)));
795 /* To skip prologues, I use this predicate. Returns either PC itself
796 if the code at PC does not look like a function prologue; otherwise
797 returns an address that (if we're lucky) follows the prologue. If
798 LENIENT, then we must skip everything which is involved in setting
799 up the frame (it's OK to skip more, just so long as we don't skip
800 anything which might clobber the registers which are being saved.
801 We must skip more in the case where part of the prologue is in the
802 delay slot of a non-prologue instruction). */
805 mips_skip_prologue (pc
, lenient
)
813 int seen_sp_adjust
= 0;
815 /* Skip the typical prologue instructions. These are the stack adjustment
816 instruction and the instructions that save registers on the stack
817 or in the gcc frame. */
818 for (offset
= 0; offset
< 100; offset
+= 4)
823 status
= read_memory_nobpt (pc
+ offset
, buf
, 4);
825 memory_error (status
, pc
+ offset
);
826 inst
= extract_unsigned_integer (buf
, 4);
828 if (lenient
&& is_delayed (inst
))
831 if ((inst
& 0xffff0000) == 0x27bd0000) /* addiu $sp,$sp,offset */
833 else if ((inst
& 0xFFE00000) == 0xAFA00000 && (inst
& 0x001F0000))
834 continue; /* sw reg,n($sp) */
836 else if ((inst
& 0xFFE00000) == 0xE7A00000) /* swc1 freg,n($sp) */
838 else if ((inst
& 0xF3E00000) == 0xA3C00000 && (inst
& 0x001F0000))
840 continue; /* reg != $zero */
841 else if (inst
== 0x03A0F021) /* move $s8,$sp */
843 else if ((inst
& 0xFF9F07FF) == 0x00800021) /* move reg,$a0-$a3 */
850 /* FIXME schauer. The following code seems no longer necessary if we
851 always skip the typical prologue instructions. */
857 /* Well, it looks like a frameless. Let's make sure.
858 Note that we are not called on the current PC,
859 but on the function`s start PC, and I have definitely
860 seen optimized code that adjusts the SP quite later */
861 b
= block_for_pc(pc
);
864 f
= lookup_symbol(MIPS_EFI_SYMBOL_NAME
, b
, LABEL_NAMESPACE
, 0, NULL
);
866 /* Ideally, I would like to use the adjusted info
867 from mips_frame_info(), but for all practical
868 purposes it will not matter (and it would require
869 a different definition of SKIP_PROLOGUE())
871 Actually, it would not hurt to skip the storing
872 of arguments on the stack as well. */
873 if (((mips_extra_func_info_t
)SYMBOL_VALUE(f
))->pdr
.frameoffset
)
880 /* Is address PC in the prologue (loosely defined) for function at
884 mips_in_lenient_prologue (startaddr
, pc
)
888 CORE_ADDR end_prologue
= mips_skip_prologue (startaddr
, 1);
889 return pc
>= startaddr
&& pc
< end_prologue
;
892 /* Given a return value in `regbuf' with a type `valtype',
893 extract and copy its value into `valbuf'. */
895 mips_extract_return_value (valtype
, regbuf
, valbuf
)
896 struct type
*valtype
;
897 char regbuf
[REGISTER_BYTES
];
902 regnum
= TYPE_CODE (valtype
) == TYPE_CODE_FLT
&& mips_fpu
? FP0_REGNUM
: 2;
904 memcpy (valbuf
, regbuf
+ REGISTER_BYTE (regnum
), TYPE_LENGTH (valtype
));
905 #ifdef REGISTER_CONVERT_TO_TYPE
906 REGISTER_CONVERT_TO_TYPE(regnum
, valtype
, valbuf
);
910 /* Given a return value in `regbuf' with a type `valtype',
911 write it's value into the appropriate register. */
913 mips_store_return_value (valtype
, valbuf
)
914 struct type
*valtype
;
918 char raw_buffer
[MAX_REGISTER_RAW_SIZE
];
920 regnum
= TYPE_CODE (valtype
) == TYPE_CODE_FLT
&& mips_fpu
? FP0_REGNUM
: 2;
921 memcpy(raw_buffer
, valbuf
, TYPE_LENGTH (valtype
));
923 #ifdef REGISTER_CONVERT_FROM_TYPE
924 REGISTER_CONVERT_FROM_TYPE(regnum
, valtype
, raw_buffer
);
927 write_register_bytes(REGISTER_BYTE (regnum
), raw_buffer
, TYPE_LENGTH (valtype
));
930 static void reinit_frame_cache_sfunc
PARAMS ((char *, int,
931 struct cmd_list_element
*));
933 /* Just like reinit_frame_cache, but with the right arguments to be
934 callable as an sfunc. */
936 reinit_frame_cache_sfunc (args
, from_tty
, c
)
939 struct cmd_list_element
*c
;
941 reinit_frame_cache ();
945 _initialize_mips_tdep ()
947 struct cmd_list_element
*c
;
949 /* Let the user turn off floating point and set the fence post for
950 heuristic_proc_start. */
953 (add_set_cmd ("mipsfpu", class_support
, var_boolean
,
955 "Set use of floating point coprocessor.\n\
956 Turn off to avoid using floating point instructions when calling functions\n\
957 or dealing with return values.", &setlist
),
960 /* We really would like to have both "0" and "unlimited" work, but
961 command.c doesn't deal with that. So make it a var_zinteger
962 because the user can always use "999999" or some such for unlimited. */
963 c
= add_set_cmd ("heuristic-fence-post", class_support
, var_zinteger
,
964 (char *) &heuristic_fence_post
,
966 Set the distance searched for the start of a function.\n\
967 If you are debugging a stripped executable, GDB needs to search through the\n\
968 program for the start of a function. This command sets the distance of the\n\
969 search. The only need to set it is when debugging a stripped executable.",
971 /* We need to throw away the frame cache when we set this, since it
972 might change our ability to get backtraces. */
973 c
->function
.sfunc
= reinit_frame_cache_sfunc
;
974 add_show_from_set (c
, &showlist
);