gdb/mips-fbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/mips.
   2
   3    Copyright (C) 2017-2022 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "osabi.h"
  22 #include "regset.h"
  23 #include "trad-frame.h"
  24 #include "tramp-frame.h"
  25
  26 #include "fbsd-tdep.h"
  27 #include "mips-tdep.h"
  28 #include "mips-fbsd-tdep.h"
  29
  30 #include "solib-svr4.h"
  31
  32 /* Core file support. */
  33
  34 /* Number of registers in `struct reg' from <machine/reg.h>.  The
  35    first 38 follow the standard MIPS layout.  The 39th holds
  36    IC_INT_REG on RM7K and RM9K processors.  The 40th is a dummy for
  37    padding.  */
  38 #define MIPS_FBSD_NUM_GREGS     40
  39
  40 /* Number of registers in `struct fpreg' from <machine/reg.h>.  The
  41    first 32 hold floating point registers.  33 holds the FSR.  The
  42    34th holds FIR on FreeBSD 12.0 and newer kernels.  On older kernels
  43    it was a zero-filled dummy for padding.  */
  44 #define MIPS_FBSD_NUM_FPREGS    34
  45
  46 /* Supply a single register.  The register size might not match, so use
  47    regcache->raw_supply_integer ().  */
  48
  49 static void
  50 mips_fbsd_supply_reg (struct regcache *regcache, int regnum, const void *addr,
  51                       size_t len)
  52 {
  53   regcache->raw_supply_integer (regnum, (const gdb_byte *) addr, len, true);
  54 }
  55
  56 /* Collect a single register.  The register size might not match, so use
  57    regcache->raw_collect_integer ().  */
  58
  59 static void
  60 mips_fbsd_collect_reg (const struct regcache *regcache, int regnum, void *addr,
  61                        size_t len)
  62 {
  63   regcache->raw_collect_integer (regnum, (gdb_byte *) addr, len, true);
  64 }
  65
  66 /* Supply the floating-point registers stored in FPREGS to REGCACHE.
  67    Each floating-point register in FPREGS is REGSIZE bytes in
  68    length.  */
  69
  70 void
  71 mips_fbsd_supply_fpregs (struct regcache *regcache, int regnum,
  72                          const void *fpregs, size_t regsize)
  73 {
  74   struct gdbarch *gdbarch = regcache->arch ();
  75   const gdb_byte *regs = (const gdb_byte *) fpregs;
  76   int i, fp0num;
  77
  78   fp0num = mips_regnum (gdbarch)->fp0;
  79   for (i = 0; i <= 32; i++)
  80     if (regnum == fp0num + i || regnum == -1)
  81       mips_fbsd_supply_reg (regcache, fp0num + i,
  82                             regs + i * regsize, regsize);
  83   if (regnum == mips_regnum (gdbarch)->fp_control_status || regnum == -1)
  84     mips_fbsd_supply_reg (regcache, mips_regnum (gdbarch)->fp_control_status,
  85                           regs + 32 * regsize, regsize);
  86   if ((regnum == mips_regnum (gdbarch)->fp_implementation_revision
  87        || regnum == -1)
  88       && extract_unsigned_integer (regs + 33 * regsize, regsize,
  89                                    gdbarch_byte_order (gdbarch)) != 0)
  90     mips_fbsd_supply_reg (regcache,
  91                           mips_regnum (gdbarch)->fp_implementation_revision,
  92                           regs + 33 * regsize, regsize);
  93 }
  94
  95 /* Supply the general-purpose registers stored in GREGS to REGCACHE.
  96    Each general-purpose register in GREGS is REGSIZE bytes in
  97    length.  */
  98
  99 void
 100 mips_fbsd_supply_gregs (struct regcache *regcache, int regnum,
 101                         const void *gregs, size_t regsize)
 102 {
 103   struct gdbarch *gdbarch = regcache->arch ();
 104   const gdb_byte *regs = (const gdb_byte *) gregs;
 105   int i;
 106
 107   for (i = 0; i <= mips_regnum (gdbarch)->pc; i++)
 108     if (regnum == i || regnum == -1)
 109       mips_fbsd_supply_reg (regcache, i, regs + i * regsize, regsize);
 110 }
 111
 112 /* Collect the floating-point registers from REGCACHE and store them
 113    in FPREGS.  Each floating-point register in FPREGS is REGSIZE bytes
 114    in length.  */
 115
 116 void
 117 mips_fbsd_collect_fpregs (const struct regcache *regcache, int regnum,
 118                           void *fpregs, size_t regsize)
 119 {
 120   struct gdbarch *gdbarch = regcache->arch ();
 121   gdb_byte *regs = (gdb_byte *) fpregs;
 122   int i, fp0num;
 123
 124   fp0num = mips_regnum (gdbarch)->fp0;
 125   for (i = 0; i < 32; i++)
 126     if (regnum == fp0num + i || regnum == -1)
 127       mips_fbsd_collect_reg (regcache, fp0num + i,
 128                              regs + i * regsize, regsize);
 129   if (regnum == mips_regnum (gdbarch)->fp_control_status || regnum == -1)
 130     mips_fbsd_collect_reg (regcache, mips_regnum (gdbarch)->fp_control_status,
 131                            regs + 32 * regsize, regsize);
 132   if (regnum == mips_regnum (gdbarch)->fp_implementation_revision
 133       || regnum == -1)
 134     mips_fbsd_collect_reg (regcache,
 135                            mips_regnum (gdbarch)->fp_implementation_revision,
 136                            regs + 33 * regsize, regsize);
 137 }
 138
 139 /* Collect the general-purpose registers from REGCACHE and store them
 140    in GREGS.  Each general-purpose register in GREGS is REGSIZE bytes
 141    in length.  */
 142
 143 void
 144 mips_fbsd_collect_gregs (const struct regcache *regcache, int regnum,
 145                          void *gregs, size_t regsize)
 146 {
 147   struct gdbarch *gdbarch = regcache->arch ();
 148   gdb_byte *regs = (gdb_byte *) gregs;
 149   int i;
 150
 151   for (i = 0; i <= mips_regnum (gdbarch)->pc; i++)
 152     if (regnum == i || regnum == -1)
 153       mips_fbsd_collect_reg (regcache, i, regs + i * regsize, regsize);
 154 }
 155
 156 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
 157    in the floating-point register set REGSET to register cache
 158    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
 159
 160 static void
 161 mips_fbsd_supply_fpregset (const struct regset *regset,
 162                            struct regcache *regcache,
 163                            int regnum, const void *fpregs, size_t len)
 164 {
 165   size_t regsize = mips_abi_regsize (regcache->arch ());
 166
 167   gdb_assert (len >= MIPS_FBSD_NUM_FPREGS * regsize);
 168
 169   mips_fbsd_supply_fpregs (regcache, regnum, fpregs, regsize);
 170 }
 171
 172 /* Collect register REGNUM from the register cache REGCACHE and store
 173    it in the buffer specified by FPREGS and LEN in the floating-point
 174    register set REGSET.  If REGNUM is -1, do this for all registers in
 175    REGSET.  */
 176
 177 static void
 178 mips_fbsd_collect_fpregset (const struct regset *regset,
 179                             const struct regcache *regcache,
 180                             int regnum, void *fpregs, size_t len)
 181 {
 182   size_t regsize = mips_abi_regsize (regcache->arch ());
 183
 184   gdb_assert (len >= MIPS_FBSD_NUM_FPREGS * regsize);
 185
 186   mips_fbsd_collect_fpregs (regcache, regnum, fpregs, regsize);
 187 }
 188
 189 /* Supply register REGNUM from the buffer specified by GREGS and LEN
 190    in the general-purpose register set REGSET to register cache
 191    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
 192
 193 static void
 194 mips_fbsd_supply_gregset (const struct regset *regset,
 195                           struct regcache *regcache, int regnum,
 196                           const void *gregs, size_t len)
 197 {
 198   size_t regsize = mips_abi_regsize (regcache->arch ());
 199
 200   gdb_assert (len >= MIPS_FBSD_NUM_GREGS * regsize);
 201
 202   mips_fbsd_supply_gregs (regcache, regnum, gregs, regsize);
 203 }
 204
 205 /* Collect register REGNUM from the register cache REGCACHE and store
 206    it in the buffer specified by GREGS and LEN in the general-purpose
 207    register set REGSET.  If REGNUM is -1, do this for all registers in
 208    REGSET.  */
 209
 210 static void
 211 mips_fbsd_collect_gregset (const struct regset *regset,
 212                            const struct regcache *regcache,
 213                            int regnum, void *gregs, size_t len)
 214 {
 215   size_t regsize = mips_abi_regsize (regcache->arch ());
 216
 217   gdb_assert (len >= MIPS_FBSD_NUM_GREGS * regsize);
 218
 219   mips_fbsd_collect_gregs (regcache, regnum, gregs, regsize);
 220 }
 221
 222 /* FreeBSD/mips register sets.  */
 223
 224 static const struct regset mips_fbsd_gregset =
 225 {
 226   NULL,
 227   mips_fbsd_supply_gregset,
 228   mips_fbsd_collect_gregset,
 229 };
 230
 231 static const struct regset mips_fbsd_fpregset =
 232 {
 233   NULL,
 234   mips_fbsd_supply_fpregset,
 235   mips_fbsd_collect_fpregset,
 236 };
 237
 238 /* Iterate over core file register note sections.  */
 239
 240 static void
 241 mips_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 242                                         iterate_over_regset_sections_cb *cb,
 243                                         void *cb_data,
 244                                         const struct regcache *regcache)
 245 {
 246   size_t regsize = mips_abi_regsize (gdbarch);
 247
 248   cb (".reg", MIPS_FBSD_NUM_GREGS * regsize, MIPS_FBSD_NUM_GREGS * regsize,
 249       &mips_fbsd_gregset, NULL, cb_data);
 250   cb (".reg2", MIPS_FBSD_NUM_FPREGS * regsize, MIPS_FBSD_NUM_FPREGS * regsize,
 251       &mips_fbsd_fpregset, NULL, cb_data);
 252 }
 253
 254 /* Signal trampoline support.  */
 255
 256 #define FBSD_SYS_sigreturn      417
 257
 258 #define MIPS_INST_LI_V0_SIGRETURN 0x24020000 + FBSD_SYS_sigreturn
 259 #define MIPS_INST_SYSCALL       0x0000000c
 260 #define MIPS_INST_BREAK         0x0000000d
 261
 262 #define O32_SIGFRAME_UCONTEXT_OFFSET    (16)
 263 #define O32_SIGSET_T_SIZE       (16)
 264
 265 #define O32_UCONTEXT_ONSTACK    (O32_SIGSET_T_SIZE)
 266 #define O32_UCONTEXT_PC         (O32_UCONTEXT_ONSTACK + 4)
 267 #define O32_UCONTEXT_REGS       (O32_UCONTEXT_PC + 4)
 268 #define O32_UCONTEXT_SR         (O32_UCONTEXT_REGS + 4 * 32)
 269 #define O32_UCONTEXT_LO         (O32_UCONTEXT_SR + 4)
 270 #define O32_UCONTEXT_HI         (O32_UCONTEXT_LO + 4)
 271 #define O32_UCONTEXT_FPUSED     (O32_UCONTEXT_HI + 4)
 272 #define O32_UCONTEXT_FPREGS     (O32_UCONTEXT_FPUSED + 4)
 273
 274 #define O32_UCONTEXT_REG_SIZE   4
 275
 276 static void
 277 mips_fbsd_sigframe_init (const struct tramp_frame *self,
 278                          struct frame_info *this_frame,
 279                          struct trad_frame_cache *cache,
 280                          CORE_ADDR func)
 281 {
 282   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 283   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 284   CORE_ADDR sp, ucontext_addr, addr;
 285   int regnum;
 286   gdb_byte buf[4];
 287
 288   /* We find the appropriate instance of `ucontext_t' at a
 289      fixed offset in the signal frame.  */
 290   sp = get_frame_register_signed (this_frame,
 291                                   MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
 292   ucontext_addr = sp + O32_SIGFRAME_UCONTEXT_OFFSET;
 293
 294   /* PC.  */
 295   regnum = mips_regnum (gdbarch)->pc;
 296   trad_frame_set_reg_addr (cache,
 297                            regnum + gdbarch_num_regs (gdbarch),
 298                            ucontext_addr + O32_UCONTEXT_PC);
 299
 300   /* GPRs.  */
 301   for (regnum = MIPS_ZERO_REGNUM, addr = ucontext_addr + O32_UCONTEXT_REGS;
 302        regnum <= MIPS_RA_REGNUM; regnum++, addr += O32_UCONTEXT_REG_SIZE)
 303     trad_frame_set_reg_addr (cache,
 304                              regnum + gdbarch_num_regs (gdbarch),
 305                              addr);
 306
 307   regnum = MIPS_PS_REGNUM;
 308   trad_frame_set_reg_addr (cache,
 309                            regnum + gdbarch_num_regs (gdbarch),
 310                            ucontext_addr + O32_UCONTEXT_SR);
 311
 312   /* HI and LO.  */
 313   regnum = mips_regnum (gdbarch)->lo;
 314   trad_frame_set_reg_addr (cache,
 315                            regnum + gdbarch_num_regs (gdbarch),
 316                            ucontext_addr + O32_UCONTEXT_LO);
 317   regnum = mips_regnum (gdbarch)->hi;
 318   trad_frame_set_reg_addr (cache,
 319                            regnum + gdbarch_num_regs (gdbarch),
 320                            ucontext_addr + O32_UCONTEXT_HI);
 321
 322   if (target_read_memory (ucontext_addr + O32_UCONTEXT_FPUSED, buf, 4) == 0
 323       && extract_unsigned_integer (buf, 4, byte_order) != 0)
 324     {
 325       for (regnum = 0, addr = ucontext_addr + O32_UCONTEXT_FPREGS;
 326            regnum < 32; regnum++, addr += O32_UCONTEXT_REG_SIZE)
 327         trad_frame_set_reg_addr (cache,
 328                                  regnum + gdbarch_fp0_regnum (gdbarch),
 329                                  addr);
 330       trad_frame_set_reg_addr (cache, mips_regnum (gdbarch)->fp_control_status,
 331                                addr);
 332     }
 333
 334   trad_frame_set_id (cache, frame_id_build (sp, func));
 335 }
 336
 337 #define MIPS_INST_ADDIU_A0_SP_O32 (0x27a40000 \
 338                                    + O32_SIGFRAME_UCONTEXT_OFFSET)
 339
 340 static const struct tramp_frame mips_fbsd_sigframe =
 341 {
 342   SIGTRAMP_FRAME,
 343   MIPS_INSN32_SIZE,
 344   {
 345     { MIPS_INST_ADDIU_A0_SP_O32, ULONGEST_MAX },        /* addiu   a0, sp, SIGF_UC */
 346     { MIPS_INST_LI_V0_SIGRETURN, ULONGEST_MAX },        /* li      v0, SYS_sigreturn */
 347     { MIPS_INST_SYSCALL, ULONGEST_MAX },                /* syscall */
 348     { MIPS_INST_BREAK, ULONGEST_MAX },          /* break */
 349     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 350   },
 351   mips_fbsd_sigframe_init
 352 };
 353
 354 #define N64_SIGFRAME_UCONTEXT_OFFSET    (32)
 355 #define N64_SIGSET_T_SIZE       (16)
 356
 357 #define N64_UCONTEXT_ONSTACK    (N64_SIGSET_T_SIZE)
 358 #define N64_UCONTEXT_PC         (N64_UCONTEXT_ONSTACK + 8)
 359 #define N64_UCONTEXT_REGS       (N64_UCONTEXT_PC + 8)
 360 #define N64_UCONTEXT_SR         (N64_UCONTEXT_REGS + 8 * 32)
 361 #define N64_UCONTEXT_LO         (N64_UCONTEXT_SR + 8)
 362 #define N64_UCONTEXT_HI         (N64_UCONTEXT_LO + 8)
 363 #define N64_UCONTEXT_FPUSED     (N64_UCONTEXT_HI + 8)
 364 #define N64_UCONTEXT_FPREGS     (N64_UCONTEXT_FPUSED + 8)
 365
 366 #define N64_UCONTEXT_REG_SIZE   8
 367
 368 static void
 369 mips64_fbsd_sigframe_init (const struct tramp_frame *self,
 370                            struct frame_info *this_frame,
 371                            struct trad_frame_cache *cache,
 372                            CORE_ADDR func)
 373 {
 374   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 375   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 376   CORE_ADDR sp, ucontext_addr, addr;
 377   int regnum;
 378   gdb_byte buf[4];
 379
 380   /* We find the appropriate instance of `ucontext_t' at a
 381      fixed offset in the signal frame.  */
 382   sp = get_frame_register_signed (this_frame,
 383                                   MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
 384   ucontext_addr = sp + N64_SIGFRAME_UCONTEXT_OFFSET;
 385
 386   /* PC.  */
 387   regnum = mips_regnum (gdbarch)->pc;
 388   trad_frame_set_reg_addr (cache,
 389                            regnum + gdbarch_num_regs (gdbarch),
 390                            ucontext_addr + N64_UCONTEXT_PC);
 391
 392   /* GPRs.  */
 393   for (regnum = MIPS_ZERO_REGNUM, addr = ucontext_addr + N64_UCONTEXT_REGS;
 394        regnum <= MIPS_RA_REGNUM; regnum++, addr += N64_UCONTEXT_REG_SIZE)
 395     trad_frame_set_reg_addr (cache,
 396                              regnum + gdbarch_num_regs (gdbarch),
 397                              addr);
 398
 399   regnum = MIPS_PS_REGNUM;
 400   trad_frame_set_reg_addr (cache,
 401                            regnum + gdbarch_num_regs (gdbarch),
 402                            ucontext_addr + N64_UCONTEXT_SR);
 403
 404   /* HI and LO.  */
 405   regnum = mips_regnum (gdbarch)->lo;
 406   trad_frame_set_reg_addr (cache,
 407                            regnum + gdbarch_num_regs (gdbarch),
 408                            ucontext_addr + N64_UCONTEXT_LO);
 409   regnum = mips_regnum (gdbarch)->hi;
 410   trad_frame_set_reg_addr (cache,
 411                            regnum + gdbarch_num_regs (gdbarch),
 412                            ucontext_addr + N64_UCONTEXT_HI);
 413
 414   if (target_read_memory (ucontext_addr + N64_UCONTEXT_FPUSED, buf, 4) == 0
 415       && extract_unsigned_integer (buf, 4, byte_order) != 0)
 416     {
 417       for (regnum = 0, addr = ucontext_addr + N64_UCONTEXT_FPREGS;
 418            regnum < 32; regnum++, addr += N64_UCONTEXT_REG_SIZE)
 419         trad_frame_set_reg_addr (cache,
 420                                  regnum + gdbarch_fp0_regnum (gdbarch),
 421                                  addr);
 422       trad_frame_set_reg_addr (cache, mips_regnum (gdbarch)->fp_control_status,
 423                                addr);
 424     }
 425
 426   trad_frame_set_id (cache, frame_id_build (sp, func));
 427 }
 428
 429 #define MIPS_INST_ADDIU_A0_SP_N32 (0x27a40000 \
 430                                    + N64_SIGFRAME_UCONTEXT_OFFSET)
 431
 432 static const struct tramp_frame mipsn32_fbsd_sigframe =
 433 {
 434   SIGTRAMP_FRAME,
 435   MIPS_INSN32_SIZE,
 436   {
 437     { MIPS_INST_ADDIU_A0_SP_N32, ULONGEST_MAX },        /* addiu   a0, sp, SIGF_UC */
 438     { MIPS_INST_LI_V0_SIGRETURN, ULONGEST_MAX },        /* li      v0, SYS_sigreturn */
 439     { MIPS_INST_SYSCALL, ULONGEST_MAX },                /* syscall */
 440     { MIPS_INST_BREAK, ULONGEST_MAX },          /* break */
 441     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 442   },
 443   mips64_fbsd_sigframe_init
 444 };
 445
 446 #define MIPS_INST_DADDIU_A0_SP_N64 (0x67a40000 \
 447                                     + N64_SIGFRAME_UCONTEXT_OFFSET)
 448
 449 static const struct tramp_frame mips64_fbsd_sigframe =
 450 {
 451   SIGTRAMP_FRAME,
 452   MIPS_INSN32_SIZE,
 453   {
 454     { MIPS_INST_DADDIU_A0_SP_N64, ULONGEST_MAX },       /* daddiu  a0, sp, SIGF_UC */
 455     { MIPS_INST_LI_V0_SIGRETURN, ULONGEST_MAX },        /* li      v0, SYS_sigreturn */
 456     { MIPS_INST_SYSCALL, ULONGEST_MAX },                /* syscall */
 457     { MIPS_INST_BREAK, ULONGEST_MAX },          /* break */
 458     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 459   },
 460   mips64_fbsd_sigframe_init
 461 };
 462
 463 /* Shared library support.  */
 464
 465 /* FreeBSD/mips can use an alternate routine in the runtime linker to
 466    resolve functions.  */
 467
 468 static CORE_ADDR
 469 mips_fbsd_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
 470 {
 471   struct bound_minimal_symbol msym
 472     = lookup_bound_minimal_symbol ("_mips_rtld_bind");
 473   if (msym.minsym != nullptr && msym.value_address () == pc)
 474     return frame_unwind_caller_pc (get_current_frame ());
 475
 476   return fbsd_skip_solib_resolver (gdbarch, pc);
 477 }
 478
 479 /* FreeBSD/mips uses a slightly different `struct link_map' than the
 480    other FreeBSD platforms as it includes an additional `l_off'
 481    member.  */
 482
 483 static struct link_map_offsets *
 484 mips_fbsd_ilp32_fetch_link_map_offsets (void)
 485 {
 486   static struct link_map_offsets lmo;
 487   static struct link_map_offsets *lmp = NULL;
 488
 489   if (lmp == NULL)
 490     {
 491       lmp = &lmo;
 492
 493       lmo.r_version_offset = 0;
 494       lmo.r_version_size = 4;
 495       lmo.r_map_offset = 4;
 496       lmo.r_brk_offset = 8;
 497       lmo.r_ldsomap_offset = -1;
 498
 499       lmo.link_map_size = 24;
 500       lmo.l_addr_offset = 0;
 501       lmo.l_name_offset = 8;
 502       lmo.l_ld_offset = 12;
 503       lmo.l_next_offset = 16;
 504       lmo.l_prev_offset = 20;
 505     }
 506
 507   return lmp;
 508 }
 509
 510 static struct link_map_offsets *
 511 mips_fbsd_lp64_fetch_link_map_offsets (void)
 512 {
 513   static struct link_map_offsets lmo;
 514   static struct link_map_offsets *lmp = NULL;
 515
 516   if (lmp == NULL)
 517     {
 518       lmp = &lmo;
 519
 520       lmo.r_version_offset = 0;
 521       lmo.r_version_size = 4;
 522       lmo.r_map_offset = 8;
 523       lmo.r_brk_offset = 16;
 524       lmo.r_ldsomap_offset = -1;
 525
 526       lmo.link_map_size = 48;
 527       lmo.l_addr_offset = 0;
 528       lmo.l_name_offset = 16;
 529       lmo.l_ld_offset = 24;
 530       lmo.l_next_offset = 32;
 531       lmo.l_prev_offset = 40;
 532     }
 533
 534   return lmp;
 535 }
 536
 537 static void
 538 mips_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 539 {
 540   enum mips_abi abi = mips_abi (gdbarch);
 541
 542   /* Generic FreeBSD support.  */
 543   fbsd_init_abi (info, gdbarch);
 544
 545   set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
 546
 547   switch (abi)
 548     {
 549       case MIPS_ABI_O32:
 550         tramp_frame_prepend_unwinder (gdbarch, &mips_fbsd_sigframe);
 551         break;
 552       case MIPS_ABI_N32:
 553         tramp_frame_prepend_unwinder (gdbarch, &mipsn32_fbsd_sigframe);
 554         break;
 555       case MIPS_ABI_N64:
 556         tramp_frame_prepend_unwinder (gdbarch, &mips64_fbsd_sigframe);
 557         break;
 558     }
 559
 560   set_gdbarch_iterate_over_regset_sections
 561     (gdbarch, mips_fbsd_iterate_over_regset_sections);
 562
 563   set_gdbarch_skip_solib_resolver (gdbarch, mips_fbsd_skip_solib_resolver);
 564
 565   /* FreeBSD/mips has SVR4-style shared libraries.  */
 566   set_solib_svr4_fetch_link_map_offsets
 567     (gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ?
 568                mips_fbsd_ilp32_fetch_link_map_offsets :
 569                mips_fbsd_lp64_fetch_link_map_offsets));
 570 }
 571
 572 void _initialize_mips_fbsd_tdep ();
 573 void
 574 _initialize_mips_fbsd_tdep ()
 575 {
 576   gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_FREEBSD,
 577                           mips_fbsd_init_abi);
 578 }