bfd/mipsbsd.c

   1 /* BFD backend for MIPS BSD (a.out) binaries.
   2    Copyright (C) 1993, 1994 Free Software Foundation, Inc.
   3    Written by Ralph Campbell.
   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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 #define BYTES_IN_WORD 4
  22 /* #define ENTRY_CAN_BE_ZERO */
  23 #define N_HEADER_IN_TEXT(x) 1
  24 #define N_SHARED_LIB(x) 0
  25 #define N_TXTADDR(x) \
  26     (N_MAGIC(x) != ZMAGIC ? (x).a_entry :       /* object file or NMAGIC */\
  27             TEXT_START_ADDR + EXEC_BYTES_SIZE   /* no padding */\
  28     )
  29 #define N_DATADDR(x) (N_TXTADDR(x)+N_TXTSIZE(x))
  30 #define TEXT_START_ADDR 4096
  31 #define PAGE_SIZE 4096
  32 #define SEGMENT_SIZE PAGE_SIZE
  33 #define DEFAULT_ARCH bfd_arch_mips
  34 #define MACHTYPE_OK(mtype) ((mtype) == M_UNKNOWN \
  35                             || (mtype) == M_MIPS1 || (mtype) == M_MIPS2)
  36 #define MY_symbol_leading_char '\0'
  37
  38 #define MY(OP) CAT(mipsbsd_,OP)
  39
  40 #include "bfd.h"
  41 #include "sysdep.h"
  42 #include "libbfd.h"
  43 #include "libaout.h"
  44
  45 #define SET_ARCH_MACH(ABFD, EXEC) \
  46   MY(set_arch_mach)(ABFD, N_MACHTYPE (EXEC)); \
  47   MY(choose_reloc_size)(ABFD);
  48 void MY(set_arch_mach) PARAMS ((bfd *abfd, int machtype));
  49 static void MY(choose_reloc_size) PARAMS ((bfd *abfd));
  50
  51 #define MY_write_object_contents MY(write_object_contents)
  52 static boolean MY(write_object_contents) PARAMS ((bfd *abfd));
  53
  54 /* We can't use MY(x) here because it leads to a recursive call to CAT
  55    when expanded inside JUMP_TABLE.  */
  56 #define MY_bfd_reloc_type_lookup mipsbsd_reloc_howto_type_lookup
  57 #define MY_canonicalize_reloc mipsbsd_canonicalize_reloc
  58
  59 #define MY_bfd_link_hash_table_create _bfd_generic_link_hash_table_create
  60 #define MY_bfd_link_add_symbols _bfd_generic_link_add_symbols
  61 #define MY_final_link_callback unused
  62 #define MY_bfd_final_link _bfd_generic_final_link
  63
  64 #define MY_backend_data &MY(backend_data)
  65 #define MY_BFD_TARGET
  66
  67 #include "aout-target.h"
  68
  69 void
  70 MY(set_arch_mach) (abfd, machtype)
  71      bfd *abfd;
  72      int machtype;
  73 {
  74   enum bfd_architecture arch;
  75   long machine;
  76
  77   /* Determine the architecture and machine type of the object file. */
  78   switch (machtype) {
  79
  80   case M_MIPS1:
  81     arch = bfd_arch_mips;
  82     machine = 3000;
  83     break;
  84
  85   case M_MIPS2:
  86     arch = bfd_arch_mips;
  87     machine = 4000;
  88     break;
  89
  90   default:
  91     arch = bfd_arch_obscure;
  92     machine = 0;
  93     break;
  94   }
  95   bfd_set_arch_mach(abfd, arch, machine);
  96 }
  97
  98 /* Determine the size of a relocation entry, based on the architecture */
  99 static void
 100 MY(choose_reloc_size) (abfd)
 101      bfd *abfd;
 102 {
 103   switch (bfd_get_arch(abfd)) {
 104   case bfd_arch_sparc:
 105   case bfd_arch_a29k:
 106   case bfd_arch_mips:
 107     obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;
 108     break;
 109   default:
 110     obj_reloc_entry_size (abfd) = RELOC_STD_SIZE;
 111     break;
 112   }
 113 }
 114
 115 /* Write an object file in BSD a.out format.
 116   Section contents have already been written.  We write the
 117   file header, symbols, and relocation.  */
 118
 119 static boolean
 120 MY(write_object_contents) (abfd)
 121      bfd *abfd;
 122 {
 123   struct external_exec exec_bytes;
 124   struct internal_exec *execp = exec_hdr (abfd);
 125
 126   /* Magic number, maestro, please!  */
 127   switch (bfd_get_arch(abfd)) {
 128   case bfd_arch_m68k:
 129     switch (bfd_get_mach(abfd)) {
 130     case 68010:
 131       N_SET_MACHTYPE(*execp, M_68010);
 132       break;
 133     default:
 134     case 68020:
 135       N_SET_MACHTYPE(*execp, M_68020);
 136       break;
 137     }
 138     break;
 139   case bfd_arch_sparc:
 140     N_SET_MACHTYPE(*execp, M_SPARC);
 141     break;
 142   case bfd_arch_i386:
 143     N_SET_MACHTYPE(*execp, M_386);
 144     break;
 145   case bfd_arch_a29k:
 146     N_SET_MACHTYPE(*execp, M_29K);
 147     break;
 148   case bfd_arch_mips:
 149     switch (bfd_get_mach(abfd)) {
 150     case 4000:
 151     case 6000:
 152       N_SET_MACHTYPE(*execp, M_MIPS2);
 153       break;
 154     default:
 155       N_SET_MACHTYPE(*execp, M_MIPS1);
 156       break;
 157     }
 158     break;
 159   default:
 160     N_SET_MACHTYPE(*execp, M_UNKNOWN);
 161   }
 162
 163   MY(choose_reloc_size)(abfd);
 164
 165   WRITE_HEADERS(abfd, execp);
 166
 167   return true;
 168 }
 169
 170 /*
 171  * MIPS relocation types.
 172  */
 173 #define MIPS_RELOC_32           0
 174 #define MIPS_RELOC_JMP          1
 175 #define MIPS_RELOC_WDISP16      2
 176 #define MIPS_RELOC_HI16         3
 177 #define MIPS_RELOC_HI16_S       4
 178 #define MIPS_RELOC_LO16         5
 179
 180 /*
 181  * This is only called when performing a BFD_RELOC_MIPS_JMP relocation.
 182  * The jump destination address is formed from the upper 4 bits of the
 183  * "current" program counter concatenated with the jump instruction's
 184  * 26 bit field and two trailing zeros.
 185  * If the destination address is not in the same segment as the "current"
 186  * program counter, then we need to signal an error.
 187  */
 188 static bfd_reloc_status_type
 189 mips_fix_jmp_addr (abfd,reloc_entry,symbol,data,input_section,output_bfd)
 190      bfd *abfd;
 191      arelent *reloc_entry;
 192      struct symbol_cache_entry *symbol;
 193      PTR data;
 194      asection *input_section;
 195      bfd *output_bfd;
 196 {
 197   bfd_vma relocation, pc;
 198
 199   /* If this is a partial relocation, just continue. */
 200   if (output_bfd != (bfd *)NULL)
 201     return bfd_reloc_continue;
 202
 203   /* If this is an undefined symbol, return error */
 204   if (bfd_is_und_section (symbol->section)
 205       && (symbol->flags & BSF_WEAK) == 0)
 206     return bfd_reloc_undefined;
 207
 208   /*
 209    * Work out which section the relocation is targetted at and the
 210    * initial relocation command value.
 211    */
 212   if (bfd_is_com_section (symbol->section))
 213     relocation = 0;
 214   else
 215     relocation = symbol->value;
 216
 217   relocation += symbol->section->output_section->vma;
 218   relocation += symbol->section->output_offset;
 219   relocation += reloc_entry->addend;
 220
 221   pc = input_section->output_section->vma + input_section->output_offset +
 222     reloc_entry->address + 4;
 223
 224   if ((relocation & 0xF0000000) != (pc & 0xF0000000))
 225     return bfd_reloc_overflow;
 226
 227   return bfd_reloc_continue;
 228 }
 229
 230 /*
 231  * This is only called when performing a BFD_RELOC_HI16_S relocation.
 232  * We need to see if bit 15 is set in the result. If it is, we add
 233  * 0x10000 and continue normally. This will compensate for the sign extension
 234  * when the low bits are added at run time.
 235  */
 236 static bfd_reloc_status_type
 237 mips_fix_hi16_s PARAMS ((bfd *, arelent *, asymbol *, PTR,
 238                          asection *, bfd *, char **));
 239
 240 static bfd_reloc_status_type
 241 mips_fix_hi16_s (abfd, reloc_entry, symbol, data, input_section,
 242                  output_bfd, error_message)
 243      bfd *abfd;
 244      arelent *reloc_entry;
 245      asymbol *symbol;
 246      PTR data;
 247      asection *input_section;
 248      bfd *output_bfd;
 249      char **error_message;
 250 {
 251   bfd_vma relocation;
 252
 253   /* If this is a partial relocation, just continue. */
 254   if (output_bfd != (bfd *)NULL)
 255     return bfd_reloc_continue;
 256
 257   /* If this is an undefined symbol, return error */
 258   if (bfd_is_und_section (symbol->section)
 259       && (symbol->flags & BSF_WEAK) == 0)
 260     return bfd_reloc_undefined;
 261
 262   /*
 263    * Work out which section the relocation is targetted at and the
 264    * initial relocation command value.
 265    */
 266   if (bfd_is_com_section (symbol->section))
 267     relocation = 0;
 268   else
 269     relocation = symbol->value;
 270
 271   relocation += symbol->section->output_section->vma;
 272   relocation += symbol->section->output_offset;
 273   relocation += reloc_entry->addend;
 274
 275   if (relocation & 0x8000)
 276     reloc_entry->addend += 0x10000;
 277
 278   return bfd_reloc_continue;
 279 }
 280
 281 static reloc_howto_type mips_howto_table_ext[] = {
 282   {MIPS_RELOC_32,      0, 2, 32, false, 0,  complain_overflow_bitfield, 0,
 283         "32",       false, 0, 0xffffffff, false},
 284   {MIPS_RELOC_JMP,     2, 2, 26, false, 0, complain_overflow_dont,
 285         mips_fix_jmp_addr,
 286         "MIPS_JMP", false, 0, 0x03ffffff, false},
 287   {MIPS_RELOC_WDISP16, 2, 2, 16, true,  0, complain_overflow_signed, 0,
 288         "WDISP16",  false, 0, 0x0000ffff, false},
 289   {MIPS_RELOC_HI16,   16, 2, 16, false, 0, complain_overflow_bitfield, 0,
 290         "HI16",     false, 0, 0x0000ffff, false},
 291   {MIPS_RELOC_HI16_S, 16, 2, 16, false, 0, complain_overflow_bitfield,
 292         mips_fix_hi16_s,
 293         "HI16_S",   false, 0, 0x0000ffff, false},
 294   {MIPS_RELOC_LO16,    0, 2, 16, false, 0, complain_overflow_dont, 0,
 295         "LO16",     false, 0, 0x0000ffff, false},
 296 };
 297
 298 static const reloc_howto_type *
 299 MY(reloc_howto_type_lookup) (abfd, code)
 300      bfd *abfd;
 301      bfd_reloc_code_real_type code;
 302 {
 303
 304   if (bfd_get_arch (abfd) != bfd_arch_mips)
 305     return 0;
 306
 307   switch (code)
 308     {
 309     case BFD_RELOC_CTOR:
 310     case BFD_RELOC_32:
 311       return (&mips_howto_table_ext[MIPS_RELOC_32]);
 312     case BFD_RELOC_MIPS_JMP:
 313       return (&mips_howto_table_ext[MIPS_RELOC_JMP]);
 314     case BFD_RELOC_16_PCREL_S2:
 315       return (&mips_howto_table_ext[MIPS_RELOC_WDISP16]);
 316     case BFD_RELOC_HI16:
 317       return (&mips_howto_table_ext[MIPS_RELOC_HI16]);
 318     case BFD_RELOC_HI16_S:
 319       return (&mips_howto_table_ext[MIPS_RELOC_HI16_S]);
 320     case BFD_RELOC_LO16:
 321       return (&mips_howto_table_ext[MIPS_RELOC_LO16]);
 322     default:
 323       return 0;
 324     }
 325 }
 326
 327 /*
 328  * This is just like the standard aoutx.h version but we need to do our
 329  * own mapping of external reloc type values to howto entries.
 330  */
 331 long
 332 MY(canonicalize_reloc)(abfd, section, relptr, symbols)
 333       bfd *abfd;
 334       sec_ptr section;
 335       arelent **relptr;
 336       asymbol **symbols;
 337 {
 338   arelent *tblptr = section->relocation;
 339   unsigned int count, c;
 340   extern reloc_howto_type NAME(aout,ext_howto_table)[];
 341
 342   /* If we have already read in the relocation table, return the values. */
 343   if (section->flags & SEC_CONSTRUCTOR) {
 344     arelent_chain *chain = section->constructor_chain;
 345
 346     for (count = 0; count < section->reloc_count; count++) {
 347       *relptr++ = &chain->relent;
 348       chain = chain->next;
 349     }
 350     *relptr = 0;
 351     return section->reloc_count;
 352   }
 353   if (tblptr && section->reloc_count) {
 354     for (count = 0; count++ < section->reloc_count;)
 355       *relptr++ = tblptr++;
 356     *relptr = 0;
 357     return section->reloc_count;
 358   }
 359
 360   if (!NAME(aout,slurp_reloc_table)(abfd, section, symbols))
 361     return -1;
 362   tblptr = section->relocation;
 363
 364   /* fix up howto entries */
 365   for (count = 0; count++ < section->reloc_count;)
 366     {
 367       c = tblptr->howto - NAME(aout,ext_howto_table);
 368       tblptr->howto = &mips_howto_table_ext[c];
 369
 370       *relptr++ = tblptr++;
 371     }
 372   *relptr = 0;
 373   return section->reloc_count;
 374 }
 375
 376 static CONST struct aout_backend_data MY(backend_data) = {
 377   0,                            /* zmagic contiguous */
 378   1,                            /* text incl header */
 379   0,                            /* exec_hdr_flags */
 380   PAGE_SIZE,                    /* text vma */
 381   MY_set_sizes,
 382   0,                            /* text size includes exec header */
 383   0,                            /* add_dynamic_symbols */
 384   0,                            /* add_one_symbol */
 385   0,                            /* link_dynamic_object */
 386   0,                            /* write_dynamic_symbol */
 387   0,                            /* check_dynamic_reloc */
 388   0                             /* finish_dynamic_link */
 389 };
 390
 391 const bfd_target aout_mips_little_vec =
 392 {
 393   "a.out-mips-little",          /* name */
 394   bfd_target_aout_flavour,
 395   false,                        /* target byte order (little) */
 396   false,                        /* target headers byte order (little) */
 397   (HAS_RELOC | EXEC_P |         /* object flags */
 398    HAS_LINENO | HAS_DEBUG |
 399    HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
 400   (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
 401   MY_symbol_leading_char,
 402   ' ',                          /* ar_pad_char */
 403   15,                           /* ar_max_namelen */
 404   1,                            /* minimum alignment */
 405   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 406      bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 407      bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
 408   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
 409      bfd_getl32, bfd_getl_signed_32, bfd_putl32,
 410      bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
 411     {_bfd_dummy_target, MY_object_p, /* bfd_check_format */
 412        bfd_generic_archive_p, MY_core_file_p},
 413     {bfd_false, MY_mkobject,    /* bfd_set_format */
 414        _bfd_generic_mkarchive, bfd_false},
 415     {bfd_false, MY_write_object_contents, /* bfd_write_contents */
 416        _bfd_write_archive_contents, bfd_false},
 417
 418      BFD_JUMP_TABLE_GENERIC (MY),
 419      BFD_JUMP_TABLE_COPY (MY),
 420      BFD_JUMP_TABLE_CORE (MY),
 421      BFD_JUMP_TABLE_ARCHIVE (MY),
 422      BFD_JUMP_TABLE_SYMBOLS (MY),
 423      BFD_JUMP_TABLE_RELOCS (MY),
 424      BFD_JUMP_TABLE_WRITE (MY),
 425      BFD_JUMP_TABLE_LINK (MY),
 426      BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 427
 428   (PTR) MY_backend_data,
 429 };
 430
 431 const bfd_target aout_mips_big_vec =
 432 {
 433   "a.out-mips-big",             /* name */
 434   bfd_target_aout_flavour,
 435   true,                         /* target byte order (big) */
 436   true,                         /* target headers byte order (big) */
 437   (HAS_RELOC | EXEC_P |         /* object flags */
 438    HAS_LINENO | HAS_DEBUG |
 439    HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
 440   (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
 441   MY_symbol_leading_char,
 442   ' ',                          /* ar_pad_char */
 443   15,                           /* ar_max_namelen */
 444   1,                            /* minimum alignment */
 445   bfd_getb64, bfd_getb_signed_64, bfd_putb64,
 446      bfd_getb32, bfd_getb_signed_32, bfd_putb32,
 447      bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */
 448   bfd_getb64, bfd_getb_signed_64, bfd_putb64,
 449      bfd_getb32, bfd_getb_signed_32, bfd_putb32,
 450      bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */
 451     {_bfd_dummy_target, MY_object_p, /* bfd_check_format */
 452        bfd_generic_archive_p, MY_core_file_p},
 453     {bfd_false, MY_mkobject,    /* bfd_set_format */
 454        _bfd_generic_mkarchive, bfd_false},
 455     {bfd_false, MY_write_object_contents, /* bfd_write_contents */
 456        _bfd_write_archive_contents, bfd_false},
 457
 458      BFD_JUMP_TABLE_GENERIC (MY),
 459      BFD_JUMP_TABLE_COPY (MY),
 460      BFD_JUMP_TABLE_CORE (MY),
 461      BFD_JUMP_TABLE_ARCHIVE (MY),
 462      BFD_JUMP_TABLE_SYMBOLS (MY),
 463      BFD_JUMP_TABLE_RELOCS (MY),
 464      BFD_JUMP_TABLE_WRITE (MY),
 465      BFD_JUMP_TABLE_LINK (MY),
 466      BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 467
 468   (PTR) MY_backend_data,
 469 };