bfd/elf32-mt.c

   1 /* Morpho Technologies MT specific support for 32-bit ELF
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006
   3    Free Software Foundation, Inc.
   4
   5    This file is part of BFD, the Binary File Descriptor library.
   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 2 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, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 #include "bfd.h"
  22 #include "sysdep.h"
  23 #include "libbfd.h"
  24 #include "elf-bfd.h"
  25 #include "elf/mt.h"
  26
  27 /* Prototypes.  */
  28 static reloc_howto_type * mt_reloc_type_lookup
  29   (bfd *, bfd_reloc_code_real_type);
  30
  31 static void mt_info_to_howto_rela
  32   (bfd *, arelent *, Elf_Internal_Rela *);
  33
  34 static bfd_reloc_status_type mt_elf_relocate_hi16
  35   (bfd *, Elf_Internal_Rela *, bfd_byte *, bfd_vma);
  36
  37 static bfd_reloc_status_type mt_final_link_relocate
  38   (reloc_howto_type *, bfd *, asection *, bfd_byte *,
  39    Elf_Internal_Rela *, bfd_vma);
  40
  41 static bfd_boolean mt_elf_relocate_section
  42   (bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
  43    Elf_Internal_Rela *, Elf_Internal_Sym *, asection **);
  44
  45 /* Relocation tables.  */
  46 static reloc_howto_type mt_elf_howto_table [] =
  47 {
  48   /* This reloc does nothing.  */
  49   HOWTO (R_MT_NONE,           /* type */
  50           0,                      /* rightshift */
  51           2,                      /* size (0 = byte, 1 = short, 2 = long) */
  52           32,                     /* bitsize */
  53           FALSE,                  /* pc_relative */
  54           0,                      /* bitpos */
  55           complain_overflow_dont, /* complain_on_overflow */
  56           bfd_elf_generic_reloc,  /* special_function */
  57           "R_MT_NONE",          /* name */
  58           FALSE,                  /* partial_inplace */
  59           0 ,                     /* src_mask */
  60           0,                      /* dst_mask */
  61           FALSE),                 /* pcrel_offset */
  62
  63   /* A 16 bit absolute relocation.  */
  64   HOWTO (R_MT_16,             /* type */
  65           0,                      /* rightshift */
  66           2,                      /* size (0 = byte, 1 = short, 2 = long) */
  67           16,                     /* bitsize */
  68           FALSE,                  /* pc_relative */
  69           0,                      /* bitpos */
  70           complain_overflow_dont, /* complain_on_overflow */
  71           bfd_elf_generic_reloc,  /* special_function */
  72           "R_MT_16",            /* name */
  73           FALSE,                  /* partial_inplace */
  74           0 ,                     /* src_mask */
  75           0xffff,                 /* dst_mask */
  76           FALSE),                 /* pcrel_offset */
  77
  78   /* A 32 bit absolute relocation.  */
  79   HOWTO (R_MT_32,             /* type */
  80           0,                      /* rightshift */
  81           2,                      /* size (0 = byte, 1 = short, 2 = long) */
  82           32,                     /* bitsize */
  83           FALSE,                  /* pc_relative */
  84           0,                      /* bitpos */
  85           complain_overflow_dont, /* complain_on_overflow */
  86           bfd_elf_generic_reloc,  /* special_function */
  87           "R_MT_32",            /* name */
  88           FALSE,                  /* partial_inplace */
  89           0 ,                     /* src_mask */
  90           0xffffffff,             /* dst_mask */
  91           FALSE),                 /* pcrel_offset */
  92
  93   /* A 32 bit pc-relative relocation.  */
  94   HOWTO (R_MT_32_PCREL,       /* type */
  95           0,                      /* rightshift */
  96           2,                      /* size (0 = byte, 1 = short, 2 = long) */
  97           32,                     /* bitsize */
  98           TRUE,                   /* pc_relative */
  99           0,                      /* bitpos */
 100           complain_overflow_dont, /* complain_on_overflow */
 101           bfd_elf_generic_reloc,  /* special_function */
 102           "R_MT_32_PCREL",    /* name */
 103           FALSE,                  /* partial_inplace */
 104           0 ,                     /* src_mask */
 105           0xffffffff,             /* dst_mask */
 106           TRUE),                  /* pcrel_offset */
 107
 108   /* A 16 bit pc-relative relocation.  */
 109   HOWTO (R_MT_PC16,           /* type */
 110           0,                      /* rightshift */
 111           2,                      /* size (0 = byte, 1 = short, 2 = long) */
 112           16,                     /* bitsize */
 113           TRUE,                   /* pc_relative */
 114           0,                      /* bitpos */
 115           complain_overflow_signed, /* complain_on_overflow */
 116           bfd_elf_generic_reloc,  /* special_function */
 117           "R_MT_PC16",          /* name */
 118           FALSE,                  /* partial_inplace */
 119           0,                      /* src_mask */
 120           0xffff,                 /* dst_mask */
 121           TRUE),                  /* pcrel_offset */
 122
 123   /* high 16 bits of symbol value.  */
 124   HOWTO (R_MT_HI16,          /* type */
 125          0,                     /* rightshift */
 126          2,                     /* size (0 = byte, 1 = short, 2 = long) */
 127          16,                    /* bitsize */
 128          FALSE,                 /* pc_relative */
 129          0,                     /* bitpos */
 130          complain_overflow_dont, /* complain_on_overflow */
 131          bfd_elf_generic_reloc, /* special_function */
 132          "R_MT_HI16",        /* name */
 133          FALSE,                  /* partial_inplace */
 134          0xffff0000,            /* src_mask */
 135          0xffff0000,            /* dst_mask */
 136          FALSE),                /* pcrel_offset */
 137
 138   /* Low 16 bits of symbol value.  */
 139   HOWTO (R_MT_LO16,          /* type */
 140          0,                     /* rightshift */
 141          2,                     /* size (0 = byte, 1 = short, 2 = long) */
 142          16,                    /* bitsize */
 143          FALSE,                 /* pc_relative */
 144          0,                     /* bitpos */
 145          complain_overflow_dont, /* complain_on_overflow */
 146          bfd_elf_generic_reloc, /* special_function */
 147          "R_MT_LO16",        /* name */
 148          FALSE,                  /* partial_inplace */
 149          0xffff,                /* src_mask */
 150          0xffff,                /* dst_mask */
 151          FALSE),                /* pcrel_offset */
 152 };
 153
 154 /* Map BFD reloc types to MT ELF reloc types.  */
 155
 156 static reloc_howto_type *
 157 mt_reloc_type_lookup
 158     (bfd *                    abfd ATTRIBUTE_UNUSED,
 159      bfd_reloc_code_real_type code)
 160 {
 161   /* Note that the mt_elf_howto_table is indxed by the R_
 162      constants.  Thus, the order that the howto records appear in the
 163      table *must* match the order of the relocation types defined in
 164      include/elf/mt.h.  */
 165
 166   switch (code)
 167     {
 168     case BFD_RELOC_NONE:
 169       return &mt_elf_howto_table[ (int) R_MT_NONE];
 170     case BFD_RELOC_16:
 171       return &mt_elf_howto_table[ (int) R_MT_16];
 172     case BFD_RELOC_32:
 173       return &mt_elf_howto_table[ (int) R_MT_32];
 174     case BFD_RELOC_32_PCREL:
 175       return &mt_elf_howto_table[ (int) R_MT_32_PCREL];
 176     case BFD_RELOC_16_PCREL:
 177       return &mt_elf_howto_table[ (int) R_MT_PC16];
 178     case BFD_RELOC_HI16:
 179       return &mt_elf_howto_table[ (int) R_MT_HI16];
 180     case BFD_RELOC_LO16:
 181       return &mt_elf_howto_table[ (int) R_MT_LO16];
 182
 183     default:
 184       /* Pacify gcc -Wall.  */
 185       return NULL;
 186     }
 187   return NULL;
 188 }
 189
 190 bfd_reloc_status_type
 191 mt_elf_relocate_hi16
 192     (bfd *               input_bfd,
 193      Elf_Internal_Rela * relhi,
 194      bfd_byte *          contents,
 195      bfd_vma             value)
 196 {
 197   bfd_vma insn;
 198
 199   insn = bfd_get_32 (input_bfd, contents + relhi->r_offset);
 200
 201   value += relhi->r_addend;
 202   value >>= 16;
 203   insn = ((insn & ~0xFFFF) | value);
 204
 205   bfd_put_32 (input_bfd, insn, contents + relhi->r_offset);
 206   return bfd_reloc_ok;
 207 }
 208 \f
 209 /* XXX: The following code is the result of a cut&paste.  This unfortunate
 210    practice is very widespread in the various target back-end files.  */
 211
 212 /* Set the howto pointer for a MT ELF reloc.  */
 213
 214 static void
 215 mt_info_to_howto_rela
 216     (bfd *               abfd ATTRIBUTE_UNUSED,
 217      arelent *           cache_ptr,
 218      Elf_Internal_Rela * dst)
 219 {
 220   unsigned int r_type;
 221
 222   r_type = ELF32_R_TYPE (dst->r_info);
 223   cache_ptr->howto = & mt_elf_howto_table [r_type];
 224 }
 225
 226 /* Perform a single relocation.  By default we use the standard BFD
 227    routines.  */
 228
 229 static bfd_reloc_status_type
 230 mt_final_link_relocate
 231     (reloc_howto_type *  howto,
 232      bfd *               input_bfd,
 233      asection *          input_section,
 234      bfd_byte *          contents,
 235      Elf_Internal_Rela * rel,
 236      bfd_vma             relocation)
 237 {
 238   return _bfd_final_link_relocate (howto, input_bfd, input_section,
 239                                    contents, rel->r_offset,
 240                                    relocation, rel->r_addend);
 241 }
 242
 243 /* Relocate a MT ELF section.
 244    There is some attempt to make this function usable for many architectures,
 245    both USE_REL and USE_RELA ['twould be nice if such a critter existed],
 246    if only to serve as a learning tool.
 247
 248    The RELOCATE_SECTION function is called by the new ELF backend linker
 249    to handle the relocations for a section.
 250
 251    The relocs are always passed as Rela structures; if the section
 252    actually uses Rel structures, the r_addend field will always be
 253    zero.
 254
 255    This function is responsible for adjusting the section contents as
 256    necessary, and (if using Rela relocs and generating a relocatable
 257    output file) adjusting the reloc addend as necessary.
 258
 259    This function does not have to worry about setting the reloc
 260    address or the reloc symbol index.
 261
 262    LOCAL_SYMS is a pointer to the swapped in local symbols.
 263
 264    LOCAL_SECTIONS is an array giving the section in the input file
 265    corresponding to the st_shndx field of each local symbol.
 266
 267    The global hash table entry for the global symbols can be found
 268    via elf_sym_hashes (input_bfd).
 269
 270    When generating relocatable output, this function must handle
 271    STB_LOCAL/STT_SECTION symbols specially.  The output symbol is
 272    going to be the section symbol corresponding to the output
 273    section, which means that the addend must be adjusted
 274    accordingly.  */
 275
 276 static bfd_boolean
 277 mt_elf_relocate_section
 278     (bfd *                   output_bfd ATTRIBUTE_UNUSED,
 279      struct bfd_link_info *  info,
 280      bfd *                   input_bfd,
 281      asection *              input_section,
 282      bfd_byte *              contents,
 283      Elf_Internal_Rela *     relocs,
 284      Elf_Internal_Sym *      local_syms,
 285      asection **             local_sections)
 286 {
 287   Elf_Internal_Shdr *           symtab_hdr;
 288   struct elf_link_hash_entry ** sym_hashes;
 289   Elf_Internal_Rela *           rel;
 290   Elf_Internal_Rela *           relend;
 291
 292   symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
 293   sym_hashes = elf_sym_hashes (input_bfd);
 294   relend     = relocs + input_section->reloc_count;
 295
 296   for (rel = relocs; rel < relend; rel ++)
 297     {
 298       reloc_howto_type *           howto;
 299       unsigned long                r_symndx;
 300       Elf_Internal_Sym *           sym;
 301       asection *                   sec;
 302       struct elf_link_hash_entry * h;
 303       bfd_vma                      relocation;
 304       bfd_reloc_status_type        r;
 305       const char *                 name = NULL;
 306       int                          r_type;
 307
 308       r_type = ELF32_R_TYPE (rel->r_info);
 309
 310       r_symndx = ELF32_R_SYM (rel->r_info);
 311
 312       /* This is a final link.  */
 313       howto  = mt_elf_howto_table + ELF32_R_TYPE (rel->r_info);
 314       h      = NULL;
 315       sym    = NULL;
 316       sec    = NULL;
 317
 318       if (r_symndx < symtab_hdr->sh_info)
 319         {
 320           sym = local_syms + r_symndx;
 321           sec = local_sections [r_symndx];
 322           relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
 323
 324           name = bfd_elf_string_from_elf_section
 325             (input_bfd, symtab_hdr->sh_link, sym->st_name);
 326           name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
 327         }
 328       else
 329         {
 330           bfd_boolean unresolved_reloc;
 331           bfd_boolean warned;
 332
 333           RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
 334                                    r_symndx, symtab_hdr, sym_hashes,
 335                                    h, sec, relocation,
 336                                    unresolved_reloc, warned);
 337
 338           name = h->root.root.string;
 339         }
 340
 341
 342       /* Finally, the sole MT-specific part.  */
 343       switch (r_type)
 344         {
 345         case R_MT_HI16:
 346           r = mt_elf_relocate_hi16 (input_bfd, rel, contents, relocation);
 347           break;
 348         default:
 349           r = mt_final_link_relocate (howto, input_bfd, input_section,
 350                                           contents, rel, relocation);
 351           break;
 352         }
 353
 354
 355       if (r != bfd_reloc_ok)
 356         {
 357           const char * msg = (const char *) NULL;
 358
 359           switch (r)
 360             {
 361             case bfd_reloc_overflow:
 362               r = info->callbacks->reloc_overflow
 363                 (info, (h ? &h->root : NULL), name, howto->name, (bfd_vma) 0,
 364                  input_bfd, input_section, rel->r_offset);
 365               break;
 366
 367             case bfd_reloc_undefined:
 368               r = info->callbacks->undefined_symbol
 369                 (info, name, input_bfd, input_section, rel->r_offset, TRUE);
 370               break;
 371
 372             case bfd_reloc_outofrange:
 373               msg = _("internal error: out of range error");
 374               break;
 375
 376             case bfd_reloc_dangerous:
 377               msg = _("internal error: dangerous relocation");
 378               break;
 379
 380             default:
 381               msg = _("internal error: unknown error");
 382               break;
 383             }
 384
 385           if (msg)
 386             r = info->callbacks->warning
 387               (info, msg, name, input_bfd, input_section, rel->r_offset);
 388
 389           if (! r)
 390             return FALSE;
 391         }
 392     }
 393
 394   return TRUE;
 395 }
 396
 397 /* Look through the relocs for a section during the first phase.
 398    Since we don't do .gots or .plts, we just need to consider the
 399    virtual table relocs for gc.  */
 400
 401 static bfd_boolean
 402 mt_elf_check_relocs
 403     (bfd *                     abfd,
 404      struct bfd_link_info *    info,
 405      asection *                sec,
 406      const Elf_Internal_Rela * relocs)
 407 {
 408   Elf_Internal_Shdr *           symtab_hdr;
 409   struct elf_link_hash_entry ** sym_hashes;
 410   struct elf_link_hash_entry ** sym_hashes_end;
 411   const Elf_Internal_Rela *     rel;
 412   const Elf_Internal_Rela *     rel_end;
 413
 414   if (info->relocatable)
 415     return TRUE;
 416
 417   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
 418   sym_hashes = elf_sym_hashes (abfd);
 419   sym_hashes_end = sym_hashes + symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
 420   if (!elf_bad_symtab (abfd))
 421     sym_hashes_end -= symtab_hdr->sh_info;
 422
 423   rel_end = relocs + sec->reloc_count;
 424   for (rel = relocs; rel < rel_end; rel++)
 425     {
 426       struct elf_link_hash_entry *h;
 427       unsigned long r_symndx;
 428
 429       r_symndx = ELF32_R_SYM (rel->r_info);
 430       if (r_symndx < symtab_hdr->sh_info)
 431         h = NULL;
 432       else
 433         {
 434           h = sym_hashes[r_symndx - symtab_hdr->sh_info];
 435           while (h->root.type == bfd_link_hash_indirect
 436                  || h->root.type == bfd_link_hash_warning)
 437             h = (struct elf_link_hash_entry *) h->root.u.i.link;
 438         }
 439     }
 440
 441   return TRUE;
 442 }
 443
 444 /* Return the MACH for an e_flags value.  */
 445
 446 static int
 447 elf32_mt_machine (bfd *abfd)
 448 {
 449   switch (elf_elfheader (abfd)->e_flags & EF_MT_CPU_MASK)
 450     {
 451     case EF_MT_CPU_MRISC:       return bfd_mach_ms1;
 452     case EF_MT_CPU_MRISC2:      return bfd_mach_mrisc2;
 453     case EF_MT_CPU_MS2:         return bfd_mach_ms2;
 454     }
 455
 456   return bfd_mach_ms1;
 457 }
 458
 459 static bfd_boolean
 460 mt_elf_object_p (bfd * abfd)
 461 {
 462   bfd_default_set_arch_mach (abfd, bfd_arch_mt, elf32_mt_machine (abfd));
 463
 464   return TRUE;
 465 }
 466
 467 /* Function to set the ELF flag bits.  */
 468
 469 static bfd_boolean
 470 mt_elf_set_private_flags (bfd *    abfd,
 471                            flagword flags)
 472 {
 473   elf_elfheader (abfd)->e_flags = flags;
 474   elf_flags_init (abfd) = TRUE;
 475   return TRUE;
 476 }
 477
 478 static bfd_boolean
 479 mt_elf_copy_private_bfd_data (bfd * ibfd, bfd * obfd)
 480 {
 481   if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
 482       || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
 483     return TRUE;
 484
 485   BFD_ASSERT (!elf_flags_init (obfd)
 486               || elf_elfheader (obfd)->e_flags == elf_elfheader (ibfd)->e_flags);
 487
 488   elf_elfheader (obfd)->e_flags = elf_elfheader (ibfd)->e_flags;
 489   elf_flags_init (obfd) = TRUE;
 490   return TRUE;
 491 }
 492
 493 /* Merge backend specific data from an object file to the output
 494    object file when linking.  */
 495
 496 static bfd_boolean
 497 mt_elf_merge_private_bfd_data (bfd * ibfd, bfd * obfd)
 498 {
 499   flagword     old_flags, new_flags;
 500   bfd_boolean  ok = TRUE;
 501
 502   /* Check if we have the same endianess.  */
 503   if (_bfd_generic_verify_endian_match (ibfd, obfd) == FALSE)
 504     return FALSE;
 505
 506   /* If they're not both mt, then merging is meaningless, so just
 507      don't do it.  */
 508   if (strcmp (ibfd->arch_info->arch_name, "mt") != 0)
 509     return TRUE;
 510   if (strcmp (obfd->arch_info->arch_name, "mt") != 0)
 511     return TRUE;
 512
 513   new_flags = elf_elfheader (ibfd)->e_flags;
 514   old_flags = elf_elfheader (obfd)->e_flags;
 515
 516 #ifdef DEBUG
 517   _bfd_error_handler ("%B: old_flags = 0x%.8lx, new_flags = 0x%.8lx, init = %s",
 518                       ibfd, old_flags, new_flags, elf_flags_init (obfd) ? "yes" : "no");
 519 #endif
 520
 521   if (!elf_flags_init (obfd))
 522     {
 523       old_flags = new_flags;
 524       elf_flags_init (obfd) = TRUE;
 525     }
 526   else if ((new_flags & EF_MT_CPU_MASK) != (old_flags & EF_MT_CPU_MASK))
 527     {
 528       /* CPU has changed.  This is invalid, because MRISC, MRISC2 and
 529          MS2 are not subsets of each other.   */
 530       ok = FALSE;
 531     }
 532
 533   if (ok)
 534     {
 535       obfd->arch_info = ibfd->arch_info;
 536       elf_elfheader (obfd)->e_flags = old_flags;
 537     }
 538
 539   return ok;
 540 }
 541
 542 static bfd_boolean
 543 mt_elf_print_private_bfd_data (bfd * abfd, void * ptr)
 544 {
 545   FILE *   file = (FILE *) ptr;
 546   flagword flags;
 547
 548   BFD_ASSERT (abfd != NULL && ptr != NULL);
 549
 550   /* Print normal ELF private data.  */
 551   _bfd_elf_print_private_bfd_data (abfd, ptr);
 552
 553   flags = elf_elfheader (abfd)->e_flags;
 554   fprintf (file, _("private flags = 0x%lx:"), (long)flags);
 555
 556   switch (flags & EF_MT_CPU_MASK)
 557     {
 558     default:
 559     case EF_MT_CPU_MRISC:   fprintf (file, " ms1-16-002");      break;
 560     case EF_MT_CPU_MRISC2:  fprintf (file, " ms1-16-003");      break;
 561     case EF_MT_CPU_MS2:     fprintf (file, " ms2");     break;
 562     }
 563
 564   fputc ('\n', file);
 565
 566   return TRUE;
 567 }
 568
 569 \f
 570 #define TARGET_BIG_SYM   bfd_elf32_mt_vec
 571 #define TARGET_BIG_NAME  "elf32-mt"
 572
 573 #define ELF_ARCH         bfd_arch_mt
 574 #define ELF_MACHINE_CODE EM_MT
 575 #define ELF_MAXPAGESIZE  1 /* No pages on the MT.  */
 576
 577 #define elf_info_to_howto_rel                   NULL
 578 #define elf_info_to_howto                       mt_info_to_howto_rela
 579
 580 #define elf_backend_relocate_section            mt_elf_relocate_section
 581
 582 #define bfd_elf32_bfd_reloc_type_lookup         mt_reloc_type_lookup
 583
 584 #define elf_backend_check_relocs                mt_elf_check_relocs
 585 #define elf_backend_object_p                    mt_elf_object_p
 586 #define elf_backend_rela_normal                 1
 587
 588 #define elf_backend_can_gc_sections             1
 589
 590 #define bfd_elf32_bfd_set_private_flags         mt_elf_set_private_flags
 591 #define bfd_elf32_bfd_copy_private_bfd_data     mt_elf_copy_private_bfd_data
 592 #define bfd_elf32_bfd_merge_private_bfd_data    mt_elf_merge_private_bfd_data
 593 #define bfd_elf32_bfd_print_private_bfd_data    mt_elf_print_private_bfd_data
 594
 595 #include "elf32-target.h"