aboutsummaryrefslogtreecommitdiff
path: root/gdb/mips-linux-tdep.c
blob: 20ada7b9477ba7e0df26df93751fab89515d6647 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
/* Target-dependent code for GNU/Linux on MIPS processors.

   Copyright 2001, 2002 Free Software Foundation, Inc.

   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 "defs.h"
#include "gdbcore.h"
#include "target.h"
#include "solib-svr4.h"
#include "osabi.h"
#include "mips-tdep.h"
#include "gdb_string.h"
#include "gdb_assert.h"

/* Copied from <asm/elf.h>.  */
#define ELF_NGREG       45
#define ELF_NFPREG      33

typedef unsigned char elf_greg_t[4];
typedef elf_greg_t elf_gregset_t[ELF_NGREG];

typedef unsigned char elf_fpreg_t[8];
typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];

/* 0 - 31 are integer registers, 32 - 63 are fp registers.  */
#define FPR_BASE        32
#define PC              64
#define CAUSE           65
#define BADVADDR        66
#define MMHI            67
#define MMLO            68
#define FPC_CSR         69
#define FPC_EIR         70

#define EF_REG0			6
#define EF_REG31		37
#define EF_LO			38
#define EF_HI			39
#define EF_CP0_EPC		40
#define EF_CP0_BADVADDR		41
#define EF_CP0_STATUS		42
#define EF_CP0_CAUSE		43

#define EF_SIZE			180

/* Figure out where the longjmp will land.
   We expect the first arg to be a pointer to the jmp_buf structure from
   which we extract the pc (MIPS_LINUX_JB_PC) that we will land at.  The pc
   is copied into PC.  This routine returns 1 on success.  */

#define MIPS_LINUX_JB_ELEMENT_SIZE 4
#define MIPS_LINUX_JB_PC 0

static int
mips_linux_get_longjmp_target (CORE_ADDR *pc)
{
  CORE_ADDR jb_addr;
  char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];

  jb_addr = read_register (A0_REGNUM);

  if (target_read_memory (jb_addr
			  + MIPS_LINUX_JB_PC * MIPS_LINUX_JB_ELEMENT_SIZE,
			  buf, TARGET_PTR_BIT / TARGET_CHAR_BIT))
    return 0;

  *pc = extract_unsigned_integer (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);

  return 1;
}

/* Transform the bits comprising a 32-bit register to the right
   size for supply_register().  This is needed when MIPS_REGSIZE is 8.  */

static void
supply_32bit_reg (int regnum, const void *addr)
{
  char buf[MAX_REGISTER_SIZE];
  store_signed_integer (buf, DEPRECATED_REGISTER_RAW_SIZE (regnum),
                        extract_signed_integer (addr, 4));
  supply_register (regnum, buf);
}

/* Unpack an elf_gregset_t into GDB's register cache.  */

void 
supply_gregset (elf_gregset_t *gregsetp)
{
  int regi;
  elf_greg_t *regp = *gregsetp;
  char zerobuf[MAX_REGISTER_SIZE];

  memset (zerobuf, 0, MAX_REGISTER_SIZE);

  for (regi = EF_REG0; regi <= EF_REG31; regi++)
    supply_32bit_reg ((regi - EF_REG0), (char *)(regp + regi));

  supply_32bit_reg (LO_REGNUM, (char *)(regp + EF_LO));
  supply_32bit_reg (HI_REGNUM, (char *)(regp + EF_HI));

  supply_32bit_reg (PC_REGNUM, (char *)(regp + EF_CP0_EPC));
  supply_32bit_reg (BADVADDR_REGNUM, (char *)(regp + EF_CP0_BADVADDR));
  supply_32bit_reg (PS_REGNUM, (char *)(regp + EF_CP0_STATUS));
  supply_32bit_reg (CAUSE_REGNUM, (char *)(regp + EF_CP0_CAUSE));

  /* Fill inaccessible registers with zero.  */
  supply_register (UNUSED_REGNUM, zerobuf);
  for (regi = FIRST_EMBED_REGNUM; regi < LAST_EMBED_REGNUM; regi++)
    supply_register (regi, zerobuf);
}

/* Pack our registers (or one register) into an elf_gregset_t.  */

void
fill_gregset (elf_gregset_t *gregsetp, int regno)
{
  int regaddr, regi;
  elf_greg_t *regp = *gregsetp;
  void *dst;

  if (regno == -1)
    {
      memset (regp, 0, sizeof (elf_gregset_t));
      for (regi = 0; regi < 32; regi++)
        fill_gregset (gregsetp, regi);
      fill_gregset (gregsetp, LO_REGNUM);
      fill_gregset (gregsetp, HI_REGNUM);
      fill_gregset (gregsetp, PC_REGNUM);
      fill_gregset (gregsetp, BADVADDR_REGNUM);
      fill_gregset (gregsetp, PS_REGNUM);
      fill_gregset (gregsetp, CAUSE_REGNUM);

      return;
   }

  if (regno < 32)
    {
      dst = regp + regno + EF_REG0;
      regcache_collect (regno, dst);
      return;
    }

  regaddr = -1;
  switch (regno)
    {
      case LO_REGNUM:
	regaddr = EF_LO;
	break;
      case HI_REGNUM:
	regaddr = EF_HI;
	break;
      case PC_REGNUM:
	regaddr = EF_CP0_EPC;
	break;
      case BADVADDR_REGNUM:
	regaddr = EF_CP0_BADVADDR;
	break;
      case PS_REGNUM:
	regaddr = EF_CP0_STATUS;
	break;
      case CAUSE_REGNUM:
	regaddr = EF_CP0_CAUSE;
	break;
    }

  if (regaddr != -1)
    {
      dst = regp + regaddr;
      regcache_collect (regno, dst);
    }
}

/* Likewise, unpack an elf_fpregset_t.  */

void
supply_fpregset (elf_fpregset_t *fpregsetp)
{
  int regi;
  char zerobuf[MAX_REGISTER_SIZE];

  memset (zerobuf, 0, MAX_REGISTER_SIZE);

  for (regi = 0; regi < 32; regi++)
    supply_register (FP0_REGNUM + regi,
		     (char *)(*fpregsetp + regi));

  supply_register (FCRCS_REGNUM, (char *)(*fpregsetp + 32));

  /* FIXME: how can we supply FCRIR_REGNUM?  The ABI doesn't tell us. */
  supply_register (FCRIR_REGNUM, zerobuf);
}

/* Likewise, pack one or all floating point registers into an
   elf_fpregset_t.  */

void
fill_fpregset (elf_fpregset_t *fpregsetp, int regno)
{
  char *from, *to;

  if ((regno >= FP0_REGNUM) && (regno < FP0_REGNUM + 32))
    {
      from = (char *) &deprecated_registers[DEPRECATED_REGISTER_BYTE (regno)];
      to = (char *) (*fpregsetp + regno - FP0_REGNUM);
      memcpy (to, from, DEPRECATED_REGISTER_RAW_SIZE (regno - FP0_REGNUM));
    }
  else if (regno == FCRCS_REGNUM)
    {
      from = (char *) &deprecated_registers[DEPRECATED_REGISTER_BYTE (regno)];
      to = (char *) (*fpregsetp + 32);
      memcpy (to, from, DEPRECATED_REGISTER_RAW_SIZE (regno));
    }
  else if (regno == -1)
    {
      int regi;

      for (regi = 0; regi < 32; regi++)
	fill_fpregset (fpregsetp, FP0_REGNUM + regi);
      fill_fpregset(fpregsetp, FCRCS_REGNUM);
    }
}

/* Map gdb internal register number to ptrace ``address''.
   These ``addresses'' are normally defined in <asm/ptrace.h>.  */

static CORE_ADDR
mips_linux_register_addr (int regno, CORE_ADDR blockend)
{
  int regaddr;

  if (regno < 0 || regno >= NUM_REGS)
    error ("Bogon register number %d.", regno);

  if (regno < 32)
    regaddr = regno;
  else if ((regno >= FP0_REGNUM) && (regno < FP0_REGNUM + 32))
    regaddr = FPR_BASE + (regno - FP0_REGNUM);
  else if (regno == PC_REGNUM)
    regaddr = PC;
  else if (regno == CAUSE_REGNUM)
    regaddr = CAUSE;
  else if (regno == BADVADDR_REGNUM)
    regaddr = BADVADDR;
  else if (regno == LO_REGNUM)
    regaddr = MMLO;
  else if (regno == HI_REGNUM)
    regaddr = MMHI;
  else if (regno == FCRCS_REGNUM)
    regaddr = FPC_CSR;
  else if (regno == FCRIR_REGNUM)
    regaddr = FPC_EIR;
  else
    error ("Unknowable register number %d.", regno);

  return regaddr;
}


/* Fetch (and possibly build) an appropriate link_map_offsets
   structure for native GNU/Linux MIPS targets using the struct offsets
   defined in link.h (but without actual reference to that file).

   This makes it possible to access GNU/Linux MIPS shared libraries from a
   GDB that was built on a different host platform (for cross debugging).  */

static struct link_map_offsets *
mips_linux_svr4_fetch_link_map_offsets (void)
{ 
  static struct link_map_offsets lmo;
  static struct link_map_offsets *lmp = NULL;

  if (lmp == NULL)
    { 
      lmp = &lmo;

      lmo.r_debug_size = 8;	/* The actual size is 20 bytes, but
				   this is all we need.  */
      lmo.r_map_offset = 4;
      lmo.r_map_size   = 4;

      lmo.link_map_size = 20;

      lmo.l_addr_offset = 0;
      lmo.l_addr_size   = 4;

      lmo.l_name_offset = 4;
      lmo.l_name_size   = 4;

      lmo.l_next_offset = 12;
      lmo.l_next_size   = 4;

      lmo.l_prev_offset = 16;
      lmo.l_prev_size   = 4;
    }

  return lmp;
}

/* Support for 64-bit ABIs.  */

/* Copied from <asm/elf.h>.  */
#define MIPS64_ELF_NGREG       45
#define MIPS64_ELF_NFPREG      33

typedef unsigned char mips64_elf_greg_t[8];
typedef mips64_elf_greg_t mips64_elf_gregset_t[MIPS64_ELF_NGREG];

typedef unsigned char mips64_elf_fpreg_t[8];
typedef mips64_elf_fpreg_t mips64_elf_fpregset_t[MIPS64_ELF_NFPREG];

/* 0 - 31 are integer registers, 32 - 63 are fp registers.  */
#define MIPS64_FPR_BASE                 32
#define MIPS64_PC                       64
#define MIPS64_CAUSE                    65
#define MIPS64_BADVADDR                 66
#define MIPS64_MMHI                     67
#define MIPS64_MMLO                     68
#define MIPS64_FPC_CSR                  69
#define MIPS64_FPC_EIR                  70

#define MIPS64_EF_REG0			 0
#define MIPS64_EF_REG31			31
#define MIPS64_EF_LO			32
#define MIPS64_EF_HI			33
#define MIPS64_EF_CP0_EPC		34
#define MIPS64_EF_CP0_BADVADDR		35
#define MIPS64_EF_CP0_STATUS		36
#define MIPS64_EF_CP0_CAUSE		37

#define MIPS64_EF_SIZE			304

/* Figure out where the longjmp will land.
   We expect the first arg to be a pointer to the jmp_buf structure from
   which we extract the pc (MIPS_LINUX_JB_PC) that we will land at.  The pc
   is copied into PC.  This routine returns 1 on success.  */

/* Details about jmp_buf.  */

#define MIPS64_LINUX_JB_PC 0

static int
mips64_linux_get_longjmp_target (CORE_ADDR *pc)
{
  CORE_ADDR jb_addr;
  void *buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT);
  int element_size = TARGET_PTR_BIT == 32 ? 4 : 8;

  jb_addr = read_register (A0_REGNUM);

  if (target_read_memory (jb_addr + MIPS64_LINUX_JB_PC * element_size,
			  buf, TARGET_PTR_BIT / TARGET_CHAR_BIT))
    return 0;

  *pc = extract_unsigned_integer (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);

  return 1;
}

/* Unpack an elf_gregset_t into GDB's register cache.  */

static void 
mips64_supply_gregset (mips64_elf_gregset_t *gregsetp)
{
  int regi;
  mips64_elf_greg_t *regp = *gregsetp;
  char zerobuf[MAX_REGISTER_SIZE];

  memset (zerobuf, 0, MAX_REGISTER_SIZE);

  for (regi = MIPS64_EF_REG0; regi <= MIPS64_EF_REG31; regi++)
    supply_register ((regi - MIPS64_EF_REG0), (char *)(regp + regi));

  supply_register (LO_REGNUM, (char *)(regp + MIPS64_EF_LO));
  supply_register (HI_REGNUM, (char *)(regp + MIPS64_EF_HI));

  supply_register (PC_REGNUM, (char *)(regp + MIPS64_EF_CP0_EPC));
  supply_register (BADVADDR_REGNUM, (char *)(regp + MIPS64_EF_CP0_BADVADDR));
  supply_register (PS_REGNUM, (char *)(regp + MIPS64_EF_CP0_STATUS));
  supply_register (CAUSE_REGNUM, (char *)(regp + MIPS64_EF_CP0_CAUSE));

  /* Fill inaccessible registers with zero.  */
  supply_register (UNUSED_REGNUM, zerobuf);
  for (regi = FIRST_EMBED_REGNUM; regi < LAST_EMBED_REGNUM; regi++)
    supply_register (regi, zerobuf);
}

/* Pack our registers (or one register) into an elf_gregset_t.  */

static void
mips64_fill_gregset (mips64_elf_gregset_t *gregsetp, int regno)
{
  int regaddr, regi;
  mips64_elf_greg_t *regp = *gregsetp;
  void *src, *dst;

  if (regno == -1)
    {
      memset (regp, 0, sizeof (mips64_elf_gregset_t));
      for (regi = 0; regi < 32; regi++)
        mips64_fill_gregset (gregsetp, regi);
      mips64_fill_gregset (gregsetp, LO_REGNUM);
      mips64_fill_gregset (gregsetp, HI_REGNUM);
      mips64_fill_gregset (gregsetp, PC_REGNUM);
      mips64_fill_gregset (gregsetp, BADVADDR_REGNUM);
      mips64_fill_gregset (gregsetp, PS_REGNUM);
      mips64_fill_gregset (gregsetp, CAUSE_REGNUM);

      return;
   }

  if (regno < 32)
    {
      dst = regp + regno + MIPS64_EF_REG0;
      regcache_collect (regno, dst);
      return;
    }

  regaddr = -1;
  switch (regno)
    {
      case LO_REGNUM:
	regaddr = MIPS64_EF_LO;
	break;
      case HI_REGNUM:
	regaddr = MIPS64_EF_HI;
	break;
      case PC_REGNUM:
	regaddr = MIPS64_EF_CP0_EPC;
	break;
      case BADVADDR_REGNUM:
	regaddr = MIPS64_EF_CP0_BADVADDR;
	break;
      case PS_REGNUM:
	regaddr = MIPS64_EF_CP0_STATUS;
	break;
      case CAUSE_REGNUM:
	regaddr = MIPS64_EF_CP0_CAUSE;
	break;
    }

  if (regaddr != -1)
    {
      dst = regp + regaddr;
      regcache_collect (regno, dst);
    }
}

/* Likewise, unpack an elf_fpregset_t.  */

static void
mips64_supply_fpregset (mips64_elf_fpregset_t *fpregsetp)
{
  int regi;
  char zerobuf[MAX_REGISTER_SIZE];

  memset (zerobuf, 0, MAX_REGISTER_SIZE);

  for (regi = 0; regi < 32; regi++)
    supply_register (FP0_REGNUM + regi,
		     (char *)(*fpregsetp + regi));

  supply_register (FCRCS_REGNUM, (char *)(*fpregsetp + 32));

  /* FIXME: how can we supply FCRIR_REGNUM?  The ABI doesn't tell us. */
  supply_register (FCRIR_REGNUM, zerobuf);
}

/* Likewise, pack one or all floating point registers into an
   elf_fpregset_t.  */

static void
mips64_fill_fpregset (mips64_elf_fpregset_t *fpregsetp, int regno)
{
  char *from, *to;

  if ((regno >= FP0_REGNUM) && (regno < FP0_REGNUM + 32))
    {
      from = (char *) &deprecated_registers[DEPRECATED_REGISTER_BYTE (regno)];
      to = (char *) (*fpregsetp + regno - FP0_REGNUM);
      memcpy (to, from, DEPRECATED_REGISTER_RAW_SIZE (regno - FP0_REGNUM));
    }
  else if (regno == FCRCS_REGNUM)
    {
      from = (char *) &deprecated_registers[DEPRECATED_REGISTER_BYTE (regno)];
      to = (char *) (*fpregsetp + 32);
      memcpy (to, from, DEPRECATED_REGISTER_RAW_SIZE (regno));
    }
  else if (regno == -1)
    {
      int regi;

      for (regi = 0; regi < 32; regi++)
	mips64_fill_fpregset (fpregsetp, FP0_REGNUM + regi);
      mips64_fill_fpregset(fpregsetp, FCRCS_REGNUM);
    }
}


/* Map gdb internal register number to ptrace ``address''.
   These ``addresses'' are normally defined in <asm/ptrace.h>.  */

static CORE_ADDR
mips64_linux_register_addr (int regno, CORE_ADDR blockend)
{
  int regaddr;

  if (regno < 0 || regno >= NUM_REGS)
    error ("Bogon register number %d.", regno);

  if (regno < 32)
    regaddr = regno;
  else if ((regno >= FP0_REGNUM) && (regno < FP0_REGNUM + 32))
    regaddr = MIPS64_FPR_BASE + (regno - FP0_REGNUM);
  else if (regno == PC_REGNUM)
    regaddr = MIPS64_PC;
  else if (regno == CAUSE_REGNUM)
    regaddr = MIPS64_CAUSE;
  else if (regno == BADVADDR_REGNUM)
    regaddr = MIPS64_BADVADDR;
  else if (regno == LO_REGNUM)
    regaddr = MIPS64_MMLO;
  else if (regno == HI_REGNUM)
    regaddr = MIPS64_MMHI;
  else if (regno == FCRCS_REGNUM)
    regaddr = MIPS64_FPC_CSR;
  else if (regno == FCRIR_REGNUM)
    regaddr = MIPS64_FPC_EIR;
  else
    error ("Unknowable register number %d.", regno);

  return regaddr;
}

/*  Use a local version of this function to get the correct types for
    regsets, until multi-arch core support is ready.  */

static void
fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
		      int which, CORE_ADDR reg_addr)
{
  elf_gregset_t gregset;
  elf_fpregset_t fpregset;
  mips64_elf_gregset_t gregset64;
  mips64_elf_fpregset_t fpregset64;

  if (which == 0)
    {
      if (core_reg_size == sizeof (gregset))
	{
	  memcpy ((char *) &gregset, core_reg_sect, sizeof (gregset));
	  supply_gregset (&gregset);
	}
      else if (core_reg_size == sizeof (gregset64))
	{
	  memcpy ((char *) &gregset64, core_reg_sect, sizeof (gregset64));
	  mips64_supply_gregset (&gregset64);
	}
      else
	{
	  warning ("wrong size gregset struct in core file");
	}
    }
  else if (which == 2)
    {
      if (core_reg_size == sizeof (fpregset))
	{
	  memcpy ((char *) &fpregset, core_reg_sect, sizeof (fpregset));
	  supply_fpregset (&fpregset);
	}
      else if (core_reg_size == sizeof (fpregset64))
	{
	  memcpy ((char *) &fpregset64, core_reg_sect, sizeof (fpregset64));
	  mips64_supply_fpregset (&fpregset64);
	}
      else
	{
	  warning ("wrong size fpregset struct in core file");
	}
    }
}

/* Register that we are able to handle ELF file formats using standard
   procfs "regset" structures.  */

static struct core_fns regset_core_fns =
{
  bfd_target_elf_flavour,		/* core_flavour */
  default_check_format,			/* check_format */
  default_core_sniffer,			/* core_sniffer */
  fetch_core_registers,			/* core_read_registers */
  NULL					/* next */
};

/* Fetch (and possibly build) an appropriate link_map_offsets
   structure for native GNU/Linux MIPS targets using the struct offsets
   defined in link.h (but without actual reference to that file).

   This makes it possible to access GNU/Linux MIPS shared libraries from a
   GDB that was built on a different host platform (for cross debugging).  */

static struct link_map_offsets *
mips64_linux_svr4_fetch_link_map_offsets (void)
{ 
  static struct link_map_offsets lmo;
  static struct link_map_offsets *lmp = NULL;

  if (lmp == NULL)
    { 
      lmp = &lmo;

      lmo.r_debug_size = 16;	/* The actual size is 40 bytes, but
				   this is all we need.  */
      lmo.r_map_offset = 8;
      lmo.r_map_size   = 8;

      lmo.link_map_size = 40;

      lmo.l_addr_offset = 0;
      lmo.l_addr_size   = 8;

      lmo.l_name_offset = 8;
      lmo.l_name_size   = 8;

      lmo.l_next_offset = 24;
      lmo.l_next_size   = 8;

      lmo.l_prev_offset = 32;
      lmo.l_prev_size   = 8;
    }

  return lmp;
}

/* Handle for obtaining pointer to the current register_addr() function
   for a given architecture.  */
static struct gdbarch_data *register_addr_data;

CORE_ADDR
register_addr (int regno, CORE_ADDR blockend)
{
  CORE_ADDR (*register_addr_ptr) (int, CORE_ADDR) =
    gdbarch_data (current_gdbarch, register_addr_data);

  gdb_assert (register_addr_ptr != 0);

  return register_addr_ptr (regno, blockend);
}

static void
set_mips_linux_register_addr (struct gdbarch *gdbarch,
                              CORE_ADDR (*register_addr_ptr) (int, CORE_ADDR))
{
  set_gdbarch_data (gdbarch, register_addr_data, register_addr_ptr);
}

static void *
init_register_addr_data (struct gdbarch *gdbarch)
{
  return 0;
}

static void
mips_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  enum mips_abi abi = mips_abi (gdbarch);

  switch (abi)
    {
      case MIPS_ABI_O32:
	set_gdbarch_get_longjmp_target (gdbarch,
	                                mips_linux_get_longjmp_target);
	set_solib_svr4_fetch_link_map_offsets
	  (gdbarch, mips_linux_svr4_fetch_link_map_offsets);
	set_mips_linux_register_addr (gdbarch, mips_linux_register_addr);
	break;
      case MIPS_ABI_N32:
	set_gdbarch_get_longjmp_target (gdbarch,
	                                mips_linux_get_longjmp_target);
	set_solib_svr4_fetch_link_map_offsets
	  (gdbarch, mips_linux_svr4_fetch_link_map_offsets);
	set_mips_linux_register_addr (gdbarch, mips64_linux_register_addr);
	break;
      case MIPS_ABI_N64:
	set_gdbarch_get_longjmp_target (gdbarch,
	                                mips64_linux_get_longjmp_target);
	set_solib_svr4_fetch_link_map_offsets
	  (gdbarch, mips64_linux_svr4_fetch_link_map_offsets);
	set_mips_linux_register_addr (gdbarch, mips64_linux_register_addr);
	break;
      default:
	internal_error (__FILE__, __LINE__, "can't handle ABI");
	break;
    }
}

void
_initialize_mips_linux_tdep (void)
{
  const struct bfd_arch_info *arch_info;

  register_addr_data =
    register_gdbarch_data (init_register_addr_data);

  for (arch_info = bfd_lookup_arch (bfd_arch_mips, 0);
       arch_info != NULL;
       arch_info = arch_info->next)
    {
      gdbarch_register_osabi (bfd_arch_mips, arch_info->mach, GDB_OSABI_LINUX,
			      mips_linux_init_abi);
    }

  add_core_fns (&regset_core_fns);
}