Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   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
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
/* IBM RS/6000 native-dependent code for GDB, the GNU debugger.

   Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996,
   1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 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 "inferior.h"
#include "target.h"
#include "gdbcore.h"
#include "xcoffsolib.h"
#include "symfile.h"
#include "objfiles.h"
#include "libbfd.h"		/* For bfd_cache_lookup (FIXME) */
#include "bfd.h"
#include "gdb-stabs.h"
#include "regcache.h"
#include "arch-utils.h"
#include "language.h"		/* for local_hex_string().  */
#include "ppc-tdep.h"
#include "exec.h"

#include <sys/ptrace.h>
#include <sys/reg.h>

#include <sys/param.h>
#include <sys/dir.h>
#include <sys/user.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <errno.h>

#include <a.out.h>
#include <sys/file.h>
#include "gdb_stat.h"
#include <sys/core.h>
#define __LDINFO_PTRACE32__	/* for __ld_info32 */
#define __LDINFO_PTRACE64__	/* for __ld_info64 */
#include <sys/ldr.h>
#include <sys/systemcfg.h>

/* On AIX4.3+, sys/ldr.h provides different versions of struct ld_info for
   debugging 32-bit and 64-bit processes.  Define a typedef and macros for
   accessing fields in the appropriate structures. */

/* In 32-bit compilation mode (which is the only mode from which ptrace()
   works on 4.3), __ld_info32 is #defined as equivalent to ld_info. */

#ifdef __ld_info32
# define ARCH3264
#endif

/* Return whether the current architecture is 64-bit. */

#ifndef ARCH3264
# define ARCH64() 0
#else
# define ARCH64() (DEPRECATED_REGISTER_RAW_SIZE (0) == 8)
#endif

/* Union of 32-bit and 64-bit ".reg" core file sections. */

typedef union {
#ifdef ARCH3264
  struct __context64 r64;
#else
  struct mstsave r64;
#endif
  struct mstsave r32;
} CoreRegs;

/* Union of 32-bit and 64-bit versions of ld_info. */

typedef union {
#ifndef ARCH3264
  struct ld_info l32;
  struct ld_info l64;
#else
  struct __ld_info32 l32;
  struct __ld_info64 l64;
#endif
} LdInfo;

/* If compiling with 32-bit and 64-bit debugging capability (e.g. AIX 4.x),
   declare and initialize a variable named VAR suitable for use as the arch64
   parameter to the various LDI_*() macros. */

#ifndef ARCH3264
# define ARCH64_DECL(var)
#else
# define ARCH64_DECL(var) int var = ARCH64 ()
#endif

/* Return LDI's FIELD for a 64-bit process if ARCH64 and for a 32-bit process
   otherwise.  This technique only works for FIELDs with the same data type in
   32-bit and 64-bit versions of ld_info. */

#ifndef ARCH3264
# define LDI_FIELD(ldi, arch64, field) (ldi)->l32.ldinfo_##field
#else
# define LDI_FIELD(ldi, arch64, field) \
  (arch64 ? (ldi)->l64.ldinfo_##field : (ldi)->l32.ldinfo_##field)
#endif

/* Return various LDI fields for a 64-bit process if ARCH64 and for a 32-bit
   process otherwise. */

#define LDI_NEXT(ldi, arch64)		LDI_FIELD(ldi, arch64, next)
#define LDI_FD(ldi, arch64)		LDI_FIELD(ldi, arch64, fd)
#define LDI_FILENAME(ldi, arch64)	LDI_FIELD(ldi, arch64, filename)

extern struct vmap *map_vmap (bfd * bf, bfd * arch);

static void vmap_exec (void);

static void vmap_ldinfo (LdInfo *);

static struct vmap *add_vmap (LdInfo *);

static int objfile_symbol_add (void *);

static void vmap_symtab (struct vmap *);

static void fetch_core_registers (char *, unsigned int, int, CORE_ADDR);

static void exec_one_dummy_insn (void);

extern void fixup_breakpoints (CORE_ADDR low, CORE_ADDR high, CORE_ADDR delta);

/* Given REGNO, a gdb register number, return the corresponding
   number suitable for use as a ptrace() parameter.  Return -1 if
   there's no suitable mapping.  Also, set the int pointed to by
   ISFLOAT to indicate whether REGNO is a floating point register.  */

static int
regmap (int regno, int *isfloat)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  *isfloat = 0;
  if (tdep->ppc_gp0_regnum <= regno && regno <= tdep->ppc_gplast_regnum)
    return regno;
  else if (FP0_REGNUM <= regno && regno <= FPLAST_REGNUM)
    {
      *isfloat = 1;
      return regno - FP0_REGNUM + FPR0;
    }
  else if (regno == PC_REGNUM)
    return IAR;
  else if (regno == tdep->ppc_ps_regnum)
    return MSR;
  else if (regno == tdep->ppc_cr_regnum)
    return CR;
  else if (regno == tdep->ppc_lr_regnum)
    return LR;
  else if (regno == tdep->ppc_ctr_regnum)
    return CTR;
  else if (regno == tdep->ppc_xer_regnum)
    return XER;
  else if (regno == tdep->ppc_fpscr_regnum)
    return FPSCR;
  else if (tdep->ppc_mq_regnum >= 0 && regno == tdep->ppc_mq_regnum)
    return MQ;
  else
    return -1;
}

/* Call ptrace(REQ, ID, ADDR, DATA, BUF). */

static int
rs6000_ptrace32 (int req, int id, int *addr, int data, int *buf)
{
  int ret = ptrace (req, id, (int *)addr, data, buf);
#if 0
  printf ("rs6000_ptrace32 (%d, %d, 0x%x, %08x, 0x%x) = 0x%x\n",
	  req, id, (unsigned int)addr, data, (unsigned int)buf, ret);
#endif
  return ret;
}

/* Call ptracex(REQ, ID, ADDR, DATA, BUF). */

static int
rs6000_ptrace64 (int req, int id, long long addr, int data, int *buf)
{
#ifdef ARCH3264
  int ret = ptracex (req, id, addr, data, buf);
#else
  int ret = 0;
#endif
#if 0
  printf ("rs6000_ptrace64 (%d, %d, 0x%llx, %08x, 0x%x) = 0x%x\n",
	  req, id, addr, data, (unsigned int)buf, ret);
#endif
  return ret;
}

/* Fetch register REGNO from the inferior. */

static void
fetch_register (int regno)
{
  int addr[MAX_REGISTER_SIZE];
  int nr, isfloat;

  /* Retrieved values may be -1, so infer errors from errno. */
  errno = 0;

  nr = regmap (regno, &isfloat);

  /* Floating-point registers. */
  if (isfloat)
    rs6000_ptrace32 (PT_READ_FPR, PIDGET (inferior_ptid), addr, nr, 0);

  /* Bogus register number. */
  else if (nr < 0)
    {
      if (regno >= NUM_REGS)
	fprintf_unfiltered (gdb_stderr,
			    "gdb error: register no %d not implemented.\n",
			    regno);
      return;
    }

  /* Fixed-point registers. */
  else
    {
      if (!ARCH64 ())
	*addr = rs6000_ptrace32 (PT_READ_GPR, PIDGET (inferior_ptid), (int *)nr, 0, 0);
      else
	{
	  /* PT_READ_GPR requires the buffer parameter to point to long long,
	     even if the register is really only 32 bits. */
	  long long buf;
	  rs6000_ptrace64 (PT_READ_GPR, PIDGET (inferior_ptid), nr, 0, (int *)&buf);
	  if (DEPRECATED_REGISTER_RAW_SIZE (regno) == 8)
	    memcpy (addr, &buf, 8);
	  else
	    *addr = buf;
	}
    }

  if (!errno)
    supply_register (regno, (char *) addr);
  else
    {
#if 0
      /* FIXME: this happens 3 times at the start of each 64-bit program. */
      perror ("ptrace read");
#endif
      errno = 0;
    }
}

/* Store register REGNO back into the inferior. */

static void
store_register (int regno)
{
  int addr[MAX_REGISTER_SIZE];
  int nr, isfloat;

  /* Fetch the register's value from the register cache.  */
  regcache_collect (regno, addr);

  /* -1 can be a successful return value, so infer errors from errno. */
  errno = 0;

  nr = regmap (regno, &isfloat);

  /* Floating-point registers. */
  if (isfloat)
    rs6000_ptrace32 (PT_WRITE_FPR, PIDGET (inferior_ptid), addr, nr, 0);

  /* Bogus register number. */
  else if (nr < 0)
    {
      if (regno >= NUM_REGS)
	fprintf_unfiltered (gdb_stderr,
			    "gdb error: register no %d not implemented.\n",
			    regno);
    }

  /* Fixed-point registers. */
  else
    {
      if (regno == SP_REGNUM)
	/* Execute one dummy instruction (which is a breakpoint) in inferior
	   process to give kernel a chance to do internal housekeeping.
	   Otherwise the following ptrace(2) calls will mess up user stack
	   since kernel will get confused about the bottom of the stack
	   (%sp). */
	exec_one_dummy_insn ();

      /* The PT_WRITE_GPR operation is rather odd.  For 32-bit inferiors,
         the register's value is passed by value, but for 64-bit inferiors,
	 the address of a buffer containing the value is passed.  */
      if (!ARCH64 ())
	rs6000_ptrace32 (PT_WRITE_GPR, PIDGET (inferior_ptid), (int *)nr, *addr, 0);
      else
	{
	  /* PT_WRITE_GPR requires the buffer parameter to point to an 8-byte
	     area, even if the register is really only 32 bits. */
	  long long buf;
	  if (DEPRECATED_REGISTER_RAW_SIZE (regno) == 8)
	    memcpy (&buf, addr, 8);
	  else
	    buf = *addr;
	  rs6000_ptrace64 (PT_WRITE_GPR, PIDGET (inferior_ptid), nr, 0, (int *)&buf);
	}
    }

  if (errno)
    {
      perror ("ptrace write");
      errno = 0;
    }
}

/* Read from the inferior all registers if REGNO == -1 and just register
   REGNO otherwise. */

void
fetch_inferior_registers (int regno)
{
  if (regno != -1)
    fetch_register (regno);

  else
    {
      struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

      /* Read 32 general purpose registers.  */
      for (regno = tdep->ppc_gp0_regnum;
           regno <= tdep->ppc_gplast_regnum;
	   regno++)
	{
	  fetch_register (regno);
	}

      /* Read general purpose floating point registers.  */
      for (regno = FP0_REGNUM; regno <= FPLAST_REGNUM; regno++)
	fetch_register (regno);

      /* Read special registers.  */
      fetch_register (PC_REGNUM);
      fetch_register (tdep->ppc_ps_regnum);
      fetch_register (tdep->ppc_cr_regnum);
      fetch_register (tdep->ppc_lr_regnum);
      fetch_register (tdep->ppc_ctr_regnum);
      fetch_register (tdep->ppc_xer_regnum);
      fetch_register (tdep->ppc_fpscr_regnum);
      if (tdep->ppc_mq_regnum >= 0)
	fetch_register (tdep->ppc_mq_regnum);
    }
}

/* Store our register values back into the inferior.
   If REGNO is -1, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */

void
store_inferior_registers (int regno)
{
  if (regno != -1)
    store_register (regno);

  else
    {
      struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

      /* Write general purpose registers first.  */
      for (regno = tdep->ppc_gp0_regnum;
           regno <= tdep->ppc_gplast_regnum;
	   regno++)
	{
	  store_register (regno);
	}

      /* Write floating point registers.  */
      for (regno = FP0_REGNUM; regno <= FPLAST_REGNUM; regno++)
	store_register (regno);

      /* Write special registers.  */
      store_register (PC_REGNUM);
      store_register (tdep->ppc_ps_regnum);
      store_register (tdep->ppc_cr_regnum);
      store_register (tdep->ppc_lr_regnum);
      store_register (tdep->ppc_ctr_regnum);
      store_register (tdep->ppc_xer_regnum);
      store_register (tdep->ppc_fpscr_regnum);
      if (tdep->ppc_mq_regnum >= 0)
	store_register (tdep->ppc_mq_regnum);
    }
}

/* Store in *TO the 32-bit word at 32-bit-aligned ADDR in the child
   process, which is 64-bit if ARCH64 and 32-bit otherwise.  Return
   success. */

static int
read_word (CORE_ADDR from, int *to, int arch64)
{
  /* Retrieved values may be -1, so infer errors from errno. */
  errno = 0;

  if (arch64)
    *to = rs6000_ptrace64 (PT_READ_I, PIDGET (inferior_ptid), from, 0, NULL);
  else
    *to = rs6000_ptrace32 (PT_READ_I, PIDGET (inferior_ptid), (int *)(long) from,
                    0, NULL);

  return !errno;
}

/* Copy LEN bytes to or from inferior's memory starting at MEMADDR
   to debugger memory starting at MYADDR.  Copy to inferior if
   WRITE is nonzero.

   Returns the length copied, which is either the LEN argument or zero.
   This xfer function does not do partial moves, since child_ops
   doesn't allow memory operations to cross below us in the target stack
   anyway.  */

int
child_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len,
		   int write, struct mem_attrib *attrib,
		   struct target_ops *target)
{
  /* Round starting address down to 32-bit word boundary. */
  int mask = sizeof (int) - 1;
  CORE_ADDR addr = memaddr & ~(CORE_ADDR)mask;

  /* Round ending address up to 32-bit word boundary. */
  int count = ((memaddr + len - addr + mask) & ~(CORE_ADDR)mask)
    / sizeof (int);

  /* Allocate word transfer buffer. */
  /* FIXME (alloca): This code, cloned from infptrace.c, is unsafe
     because it uses alloca to allocate a buffer of arbitrary size.
     For very large xfers, this could crash GDB's stack.  */
  int *buf = (int *) alloca (count * sizeof (int));

  int arch64 = ARCH64 ();
  int i;

  if (!write)
    {
      /* Retrieve memory a word at a time. */
      for (i = 0; i < count; i++, addr += sizeof (int))
	{
	  if (!read_word (addr, buf + i, arch64))
	    return 0;
	  QUIT;
	}

      /* Copy memory to supplied buffer. */
      addr -= count * sizeof (int);
      memcpy (myaddr, (char *)buf + (memaddr - addr), len);
    }
  else
    {
      /* Fetch leading memory needed for alignment. */
      if (addr < memaddr)
	if (!read_word (addr, buf, arch64))
	  return 0;

      /* Fetch trailing memory needed for alignment. */
      if (addr + count * sizeof (int) > memaddr + len)
	if (!read_word (addr + (count - 1) * sizeof (int),
                        buf + count - 1, arch64))
	  return 0;

      /* Copy supplied data into memory buffer. */
      memcpy ((char *)buf + (memaddr - addr), myaddr, len);

      /* Store memory one word at a time. */
      for (i = 0, errno = 0; i < count; i++, addr += sizeof (int))
	{
	  if (arch64)
	    rs6000_ptrace64 (PT_WRITE_D, PIDGET (inferior_ptid), addr, buf[i], NULL);
	  else
	    rs6000_ptrace32 (PT_WRITE_D, PIDGET (inferior_ptid), (int *)(long) addr,
		      buf[i], NULL);

	  if (errno)
	    return 0;
	  QUIT;
	}
    }

  return len;
}

/* Execute one dummy breakpoint instruction.  This way we give the kernel
   a chance to do some housekeeping and update inferior's internal data,
   including u_area. */

static void
exec_one_dummy_insn (void)
{
#define	DUMMY_INSN_ADDR	(TEXT_SEGMENT_BASE)+0x200

  char shadow_contents[BREAKPOINT_MAX];		/* Stash old bkpt addr contents */
  int ret, status, pid;
  CORE_ADDR prev_pc;

  /* We plant one dummy breakpoint into DUMMY_INSN_ADDR address. We
     assume that this address will never be executed again by the real
     code. */

  target_insert_breakpoint (DUMMY_INSN_ADDR, shadow_contents);

  /* You might think this could be done with a single ptrace call, and
     you'd be correct for just about every platform I've ever worked
     on.  However, rs6000-ibm-aix4.1.3 seems to have screwed this up --
     the inferior never hits the breakpoint (it's also worth noting
     powerpc-ibm-aix4.1.3 works correctly).  */
  prev_pc = read_pc ();
  write_pc (DUMMY_INSN_ADDR);
  if (ARCH64 ())
    ret = rs6000_ptrace64 (PT_CONTINUE, PIDGET (inferior_ptid), 1, 0, NULL);
  else
    ret = rs6000_ptrace32 (PT_CONTINUE, PIDGET (inferior_ptid), (int *)1, 0, NULL);

  if (ret != 0)
    perror ("pt_continue");

  do
    {
      pid = wait (&status);
    }
  while (pid != PIDGET (inferior_ptid));

  write_pc (prev_pc);
  target_remove_breakpoint (DUMMY_INSN_ADDR, shadow_contents);
}

/* Fetch registers from the register section in core bfd. */

static void
fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
		      int which, CORE_ADDR reg_addr)
{
  CoreRegs *regs;
  int regi;
  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); 

  if (which != 0)
    {
      fprintf_unfiltered
	(gdb_stderr,
	 "Gdb error: unknown parameter to fetch_core_registers().\n");
      return;
    }

  regs = (CoreRegs *) core_reg_sect;

  /* Put the register values from the core file section in the regcache.  */

  if (ARCH64 ())
    {
      for (regi = 0; regi < 32; regi++)
        supply_register (regi, (char *) &regs->r64.gpr[regi]);

      for (regi = 0; regi < 32; regi++)
	supply_register (FP0_REGNUM + regi, (char *) &regs->r64.fpr[regi]);

      supply_register (PC_REGNUM, (char *) &regs->r64.iar);
      supply_register (tdep->ppc_ps_regnum, (char *) &regs->r64.msr);
      supply_register (tdep->ppc_cr_regnum, (char *) &regs->r64.cr);
      supply_register (tdep->ppc_lr_regnum, (char *) &regs->r64.lr);
      supply_register (tdep->ppc_ctr_regnum, (char *) &regs->r64.ctr);
      supply_register (tdep->ppc_xer_regnum, (char *) &regs->r64.xer);
      supply_register (tdep->ppc_fpscr_regnum, (char *) &regs->r64.fpscr);
    }
  else
    {
      for (regi = 0; regi < 32; regi++)
        supply_register (regi, (char *) &regs->r32.gpr[regi]);

      for (regi = 0; regi < 32; regi++)
	supply_register (FP0_REGNUM + regi, (char *) &regs->r32.fpr[regi]);

      supply_register (PC_REGNUM, (char *) &regs->r32.iar);
      supply_register (tdep->ppc_ps_regnum, (char *) &regs->r32.msr);
      supply_register (tdep->ppc_cr_regnum, (char *) &regs->r32.cr);
      supply_register (tdep->ppc_lr_regnum, (char *) &regs->r32.lr);
      supply_register (tdep->ppc_ctr_regnum, (char *) &regs->r32.ctr);
      supply_register (tdep->ppc_xer_regnum, (char *) &regs->r32.xer);
      supply_register (tdep->ppc_fpscr_regnum, (char *) &regs->r32.fpscr);
      if (tdep->ppc_mq_regnum >= 0)
	supply_register (tdep->ppc_mq_regnum, (char *) &regs->r32.mq);
    }
}


/* Copy information about text and data sections from LDI to VP for a 64-bit
   process if ARCH64 and for a 32-bit process otherwise. */

static void
vmap_secs (struct vmap *vp, LdInfo *ldi, int arch64)
{
  if (arch64)
    {
      vp->tstart = (CORE_ADDR) ldi->l64.ldinfo_textorg;
      vp->tend = vp->tstart + ldi->l64.ldinfo_textsize;
      vp->dstart = (CORE_ADDR) ldi->l64.ldinfo_dataorg;
      vp->dend = vp->dstart + ldi->l64.ldinfo_datasize;
    }
  else
    {
      vp->tstart = (unsigned long) ldi->l32.ldinfo_textorg;
      vp->tend = vp->tstart + ldi->l32.ldinfo_textsize;
      vp->dstart = (unsigned long) ldi->l32.ldinfo_dataorg;
      vp->dend = vp->dstart + ldi->l32.ldinfo_datasize;
    }

  /* The run time loader maps the file header in addition to the text
     section and returns a pointer to the header in ldinfo_textorg.
     Adjust the text start address to point to the real start address
     of the text section.  */
  vp->tstart += vp->toffs;
}

/* handle symbol translation on vmapping */

static void
vmap_symtab (struct vmap *vp)
{
  struct objfile *objfile;
  struct section_offsets *new_offsets;
  int i;

  objfile = vp->objfile;
  if (objfile == NULL)
    {
      /* OK, it's not an objfile we opened ourselves.
         Currently, that can only happen with the exec file, so
         relocate the symbols for the symfile.  */
      if (symfile_objfile == NULL)
	return;
      objfile = symfile_objfile;
    }
  else if (!vp->loaded)
    /* If symbols are not yet loaded, offsets are not yet valid. */
    return;

  new_offsets =
    (struct section_offsets *)
    alloca (SIZEOF_N_SECTION_OFFSETS (objfile->num_sections));

  for (i = 0; i < objfile->num_sections; ++i)
    new_offsets->offsets[i] = ANOFFSET (objfile->section_offsets, i);

  /* The symbols in the object file are linked to the VMA of the section,
     relocate them VMA relative.  */
  new_offsets->offsets[SECT_OFF_TEXT (objfile)] = vp->tstart - vp->tvma;
  new_offsets->offsets[SECT_OFF_DATA (objfile)] = vp->dstart - vp->dvma;
  new_offsets->offsets[SECT_OFF_BSS (objfile)] = vp->dstart - vp->dvma;

  objfile_relocate (objfile, new_offsets);
}

/* Add symbols for an objfile.  */

static int
objfile_symbol_add (void *arg)
{
  struct objfile *obj = (struct objfile *) arg;

  syms_from_objfile (obj, NULL, 0, 0, 0, 0);
  new_symfile_objfile (obj, 0, 0);
  return 1;
}

/* Add symbols for a vmap. Return zero upon error.  */

int
vmap_add_symbols (struct vmap *vp)
{
  if (catch_errors (objfile_symbol_add, vp->objfile,
		    "Error while reading shared library symbols:\n",
		    RETURN_MASK_ALL))
    {
      /* Note this is only done if symbol reading was successful.  */
      vp->loaded = 1;
      vmap_symtab (vp);
      return 1;
    }
  return 0;
}

/* Add a new vmap entry based on ldinfo() information.

   If ldi->ldinfo_fd is not valid (e.g. this struct ld_info is from a
   core file), the caller should set it to -1, and we will open the file.

   Return the vmap new entry.  */

static struct vmap *
add_vmap (LdInfo *ldi)
{
  bfd *abfd, *last;
  char *mem, *objname, *filename;
  struct objfile *obj;
  struct vmap *vp;
  int fd;
  ARCH64_DECL (arch64);

  /* This ldi structure was allocated using alloca() in 
     xcoff_relocate_symtab(). Now we need to have persistent object 
     and member names, so we should save them. */

  filename = LDI_FILENAME (ldi, arch64);
  mem = filename + strlen (filename) + 1;
  mem = savestring (mem, strlen (mem));
  objname = savestring (filename, strlen (filename));

  fd = LDI_FD (ldi, arch64);
  if (fd < 0)
    /* Note that this opens it once for every member; a possible
       enhancement would be to only open it once for every object.  */
    abfd = bfd_openr (objname, gnutarget);
  else
    abfd = bfd_fdopenr (objname, gnutarget, fd);
  if (!abfd)
    {
      warning ("Could not open `%s' as an executable file: %s",
	       objname, bfd_errmsg (bfd_get_error ()));
      return NULL;
    }

  /* make sure we have an object file */

  if (bfd_check_format (abfd, bfd_object))
    vp = map_vmap (abfd, 0);

  else if (bfd_check_format (abfd, bfd_archive))
    {
      last = 0;
      /* FIXME??? am I tossing BFDs?  bfd? */
      while ((last = bfd_openr_next_archived_file (abfd, last)))
	if (DEPRECATED_STREQ (mem, last->filename))
	  break;

      if (!last)
	{
	  warning ("\"%s\": member \"%s\" missing.", objname, mem);
	  bfd_close (abfd);
	  return NULL;
	}

      if (!bfd_check_format (last, bfd_object))
	{
	  warning ("\"%s\": member \"%s\" not in executable format: %s.",
		   objname, mem, bfd_errmsg (bfd_get_error ()));
	  bfd_close (last);
	  bfd_close (abfd);
	  return NULL;
	}

      vp = map_vmap (last, abfd);
    }
  else
    {
      warning ("\"%s\": not in executable format: %s.",
	       objname, bfd_errmsg (bfd_get_error ()));
      bfd_close (abfd);
      return NULL;
    }
  obj = allocate_objfile (vp->bfd, 0);
  vp->objfile = obj;

  /* Always add symbols for the main objfile.  */
  if (vp == vmap || auto_solib_add)
    vmap_add_symbols (vp);
  return vp;
}

/* update VMAP info with ldinfo() information
   Input is ptr to ldinfo() results.  */

static void
vmap_ldinfo (LdInfo *ldi)
{
  struct stat ii, vi;
  struct vmap *vp;
  int got_one, retried;
  int got_exec_file = 0;
  uint next;
  int arch64 = ARCH64 ();

  /* For each *ldi, see if we have a corresponding *vp.
     If so, update the mapping, and symbol table.
     If not, add an entry and symbol table.  */

  do
    {
      char *name = LDI_FILENAME (ldi, arch64);
      char *memb = name + strlen (name) + 1;
      int fd = LDI_FD (ldi, arch64);

      retried = 0;

      if (fstat (fd, &ii) < 0)
	{
	  /* The kernel sets ld_info to -1, if the process is still using the
	     object, and the object is removed. Keep the symbol info for the
	     removed object and issue a warning.  */
	  warning ("%s (fd=%d) has disappeared, keeping its symbols",
		   name, fd);
	  continue;
	}
    retry:
      for (got_one = 0, vp = vmap; vp; vp = vp->nxt)
	{
	  struct objfile *objfile;

	  /* First try to find a `vp', which is the same as in ldinfo.
	     If not the same, just continue and grep the next `vp'. If same,
	     relocate its tstart, tend, dstart, dend values. If no such `vp'
	     found, get out of this for loop, add this ldi entry as a new vmap
	     (add_vmap) and come back, find its `vp' and so on... */

	  /* The filenames are not always sufficient to match on. */

	  if ((name[0] == '/' && !DEPRECATED_STREQ (name, vp->name))
	      || (memb[0] && !DEPRECATED_STREQ (memb, vp->member)))
	    continue;

	  /* See if we are referring to the same file.
	     We have to check objfile->obfd, symfile.c:reread_symbols might
	     have updated the obfd after a change.  */
	  objfile = vp->objfile == NULL ? symfile_objfile : vp->objfile;
	  if (objfile == NULL
	      || objfile->obfd == NULL
	      || bfd_stat (objfile->obfd, &vi) < 0)
	    {
	      warning ("Unable to stat %s, keeping its symbols", name);
	      continue;
	    }

	  if (ii.st_dev != vi.st_dev || ii.st_ino != vi.st_ino)
	    continue;

	  if (!retried)
	    close (fd);

	  ++got_one;

	  /* Found a corresponding VMAP.  Remap!  */

	  vmap_secs (vp, ldi, arch64);

	  /* The objfile is only NULL for the exec file.  */
	  if (vp->objfile == NULL)
	    got_exec_file = 1;

	  /* relocate symbol table(s). */
	  vmap_symtab (vp);

	  /* Announce new object files.  Doing this after symbol relocation
	     makes aix-thread.c's job easier. */
	  if (target_new_objfile_hook && vp->objfile)
	    target_new_objfile_hook (vp->objfile);

	  /* There may be more, so we don't break out of the loop.  */
	}

      /* if there was no matching *vp, we must perforce create the sucker(s) */
      if (!got_one && !retried)
	{
	  add_vmap (ldi);
	  ++retried;
	  goto retry;
	}
    }
  while ((next = LDI_NEXT (ldi, arch64))
	 && (ldi = (void *) (next + (char *) ldi)));

  /* If we don't find the symfile_objfile anywhere in the ldinfo, it
     is unlikely that the symbol file is relocated to the proper
     address.  And we might have attached to a process which is
     running a different copy of the same executable.  */
  if (symfile_objfile != NULL && !got_exec_file)
    {
      warning ("Symbol file %s\nis not mapped; discarding it.\n\
If in fact that file has symbols which the mapped files listed by\n\
\"info files\" lack, you can load symbols with the \"symbol-file\" or\n\
\"add-symbol-file\" commands (note that you must take care of relocating\n\
symbols to the proper address).",
	       symfile_objfile->name);
      free_objfile (symfile_objfile);
      symfile_objfile = NULL;
    }
  breakpoint_re_set ();
}

/* As well as symbol tables, exec_sections need relocation. After
   the inferior process' termination, there will be a relocated symbol
   table exist with no corresponding inferior process. At that time, we
   need to use `exec' bfd, rather than the inferior process's memory space
   to look up symbols.

   `exec_sections' need to be relocated only once, as long as the exec
   file remains unchanged.
 */

static void
vmap_exec (void)
{
  static bfd *execbfd;
  int i;

  if (execbfd == exec_bfd)
    return;

  execbfd = exec_bfd;

  if (!vmap || !exec_ops.to_sections)
    error ("vmap_exec: vmap or exec_ops.to_sections == 0\n");

  for (i = 0; &exec_ops.to_sections[i] < exec_ops.to_sections_end; i++)
    {
      if (DEPRECATED_STREQ (".text", exec_ops.to_sections[i].the_bfd_section->name))
	{
	  exec_ops.to_sections[i].addr += vmap->tstart - vmap->tvma;
	  exec_ops.to_sections[i].endaddr += vmap->tstart - vmap->tvma;
	}
      else if (DEPRECATED_STREQ (".data", exec_ops.to_sections[i].the_bfd_section->name))
	{
	  exec_ops.to_sections[i].addr += vmap->dstart - vmap->dvma;
	  exec_ops.to_sections[i].endaddr += vmap->dstart - vmap->dvma;
	}
      else if (DEPRECATED_STREQ (".bss", exec_ops.to_sections[i].the_bfd_section->name))
	{
	  exec_ops.to_sections[i].addr += vmap->dstart - vmap->dvma;
	  exec_ops.to_sections[i].endaddr += vmap->dstart - vmap->dvma;
	}
    }
}

/* Set the current architecture from the host running GDB.  Called when
   starting a child process. */

static void
set_host_arch (int pid)
{
  enum bfd_architecture arch;
  unsigned long mach;
  bfd abfd;
  struct gdbarch_info info;

  if (__power_rs ())
    {
      arch = bfd_arch_rs6000;
      mach = bfd_mach_rs6k;
    }
  else
    {
      arch = bfd_arch_powerpc;
      mach = bfd_mach_ppc;
    }

  /* FIXME: schauer/2002-02-25:
     We don't know if we are executing a 32 or 64 bit executable,
     and have no way to pass the proper word size to rs6000_gdbarch_init.
     So we have to avoid switching to a new architecture, if the architecture
     matches already.
     Blindly calling rs6000_gdbarch_init used to work in older versions of
     GDB, as rs6000_gdbarch_init incorrectly used the previous tdep to
     determine the wordsize.  */
  if (exec_bfd)
    {
      const struct bfd_arch_info *exec_bfd_arch_info;

      exec_bfd_arch_info = bfd_get_arch_info (exec_bfd);
      if (arch == exec_bfd_arch_info->arch)
	return;
    }

  bfd_default_set_arch_mach (&abfd, arch, mach);

  gdbarch_info_init (&info);
  info.bfd_arch_info = bfd_get_arch_info (&abfd);
  info.abfd = exec_bfd;

  if (!gdbarch_update_p (info))
    {
      internal_error (__FILE__, __LINE__,
		      "set_host_arch: failed to select architecture");
    }
}


/* xcoff_relocate_symtab -      hook for symbol table relocation.
   also reads shared libraries.. */

void
xcoff_relocate_symtab (unsigned int pid)
{
  int load_segs = 64; /* number of load segments */
  int rc;
  LdInfo *ldi = NULL;
  int arch64 = ARCH64 ();
  int ldisize = arch64 ? sizeof (ldi->l64) : sizeof (ldi->l32);
  int size;

  do
    {
      size = load_segs * ldisize;
      ldi = (void *) xrealloc (ldi, size);

#if 0
      /* According to my humble theory, AIX has some timing problems and
         when the user stack grows, kernel doesn't update stack info in time
         and ptrace calls step on user stack. That is why we sleep here a
         little, and give kernel to update its internals. */
      usleep (36000);
#endif

      if (arch64)
	rc = rs6000_ptrace64 (PT_LDINFO, pid, (unsigned long) ldi, size, NULL);
      else
	rc = rs6000_ptrace32 (PT_LDINFO, pid, (int *) ldi, size, NULL);

      if (rc == -1)
        {
          if (errno == ENOMEM)
            load_segs *= 2;
          else
            perror_with_name ("ptrace ldinfo");
        }
      else
	{
          vmap_ldinfo (ldi);
          vmap_exec (); /* relocate the exec and core sections as well. */
	}
    } while (rc == -1);
  if (ldi)
    xfree (ldi);
}

/* Core file stuff.  */

/* Relocate symtabs and read in shared library info, based on symbols
   from the core file.  */

void
xcoff_relocate_core (struct target_ops *target)
{
  struct bfd_section *ldinfo_sec;
  int offset = 0;
  LdInfo *ldi;
  struct vmap *vp;
  int arch64 = ARCH64 ();

  /* Size of a struct ld_info except for the variable-length filename. */
  int nonfilesz = (int)LDI_FILENAME ((LdInfo *)0, arch64);

  /* Allocated size of buffer.  */
  int buffer_size = nonfilesz;
  char *buffer = xmalloc (buffer_size);
  struct cleanup *old = make_cleanup (free_current_contents, &buffer);

  ldinfo_sec = bfd_get_section_by_name (core_bfd, ".ldinfo");
  if (ldinfo_sec == NULL)
    {
    bfd_err:
      fprintf_filtered (gdb_stderr, "Couldn't get ldinfo from core file: %s\n",
			bfd_errmsg (bfd_get_error ()));
      do_cleanups (old);
      return;
    }
  do
    {
      int i;
      int names_found = 0;

      /* Read in everything but the name.  */
      if (bfd_get_section_contents (core_bfd, ldinfo_sec, buffer,
				    offset, nonfilesz) == 0)
	goto bfd_err;

      /* Now the name.  */
      i = nonfilesz;
      do
	{
	  if (i == buffer_size)
	    {
	      buffer_size *= 2;
	      buffer = xrealloc (buffer, buffer_size);
	    }
	  if (bfd_get_section_contents (core_bfd, ldinfo_sec, &buffer[i],
					offset + i, 1) == 0)
	    goto bfd_err;
	  if (buffer[i++] == '\0')
	    ++names_found;
	}
      while (names_found < 2);

      ldi = (LdInfo *) buffer;

      /* Can't use a file descriptor from the core file; need to open it.  */
      if (arch64)
	ldi->l64.ldinfo_fd = -1;
      else
	ldi->l32.ldinfo_fd = -1;

      /* The first ldinfo is for the exec file, allocated elsewhere.  */
      if (offset == 0 && vmap != NULL)
	vp = vmap;
      else
	vp = add_vmap (ldi);

      /* Process next shared library upon error. */
      offset += LDI_NEXT (ldi, arch64);
      if (vp == NULL)
	continue;

      vmap_secs (vp, ldi, arch64);

      /* Unless this is the exec file,
         add our sections to the section table for the core target.  */
      if (vp != vmap)
	{
	  struct section_table *stp;

	  target_resize_to_sections (target, 2);
	  stp = target->to_sections_end - 2;

	  stp->bfd = vp->bfd;
	  stp->the_bfd_section = bfd_get_section_by_name (stp->bfd, ".text");
	  stp->addr = vp->tstart;
	  stp->endaddr = vp->tend;
	  stp++;

	  stp->bfd = vp->bfd;
	  stp->the_bfd_section = bfd_get_section_by_name (stp->bfd, ".data");
	  stp->addr = vp->dstart;
	  stp->endaddr = vp->dend;
	}

      vmap_symtab (vp);

      if (target_new_objfile_hook && vp != vmap && vp->objfile)
	target_new_objfile_hook (vp->objfile);
    }
  while (LDI_NEXT (ldi, arch64) != 0);
  vmap_exec ();
  breakpoint_re_set ();
  do_cleanups (old);
}

int
kernel_u_size (void)
{
  return (sizeof (struct user));
}

/* Under AIX, we have to pass the correct TOC pointer to a function
   when calling functions in the inferior.
   We try to find the relative toc offset of the objfile containing PC
   and add the current load address of the data segment from the vmap.  */

static CORE_ADDR
find_toc_address (CORE_ADDR pc)
{
  struct vmap *vp;
  extern CORE_ADDR get_toc_offset (struct objfile *);	/* xcoffread.c */

  for (vp = vmap; vp; vp = vp->nxt)
    {
      if (pc >= vp->tstart && pc < vp->tend)
	{
	  /* vp->objfile is only NULL for the exec file.  */
	  return vp->dstart + get_toc_offset (vp->objfile == NULL
					      ? symfile_objfile
					      : vp->objfile);
	}
    }
  error ("Unable to find TOC entry for pc %s\n", local_hex_string (pc));
}

/* Register that we are able to handle rs6000 core file formats. */

static struct core_fns rs6000_core_fns =
{
  bfd_target_xcoff_flavour,		/* core_flavour */
  default_check_format,			/* check_format */
  default_core_sniffer,			/* core_sniffer */
  fetch_core_registers,			/* core_read_registers */
  NULL					/* next */
};

void
_initialize_core_rs6000 (void)
{
  /* Initialize hook in rs6000-tdep.c for determining the TOC address when
     calling functions in the inferior.  */
  rs6000_find_toc_address_hook = find_toc_address;

  /* Initialize hook in rs6000-tdep.c to set the current architecture when
     starting a child process. */
  rs6000_set_host_arch_hook = set_host_arch;

  add_core_fns (&rs6000_core_fns);
}