bfd/i386lynx.c

   1 /* BFD back-end for i386 a.out binaries under LynxOS.
   2    Copyright (C) 1990-2018 Free Software Foundation, Inc.
   3
   4    This file is part of BFD, the Binary File Descriptor library.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 #define TEXT_START_ADDR 0
  22 #define TARGET_PAGE_SIZE 4096
  23 #define SEGMENT_SIZE TARGET_PAGE_SIZE
  24 #define DEFAULT_ARCH bfd_arch_i386
  25
  26 /* Do not "beautify" the CONCAT* macro args.  Traditional C will not
  27    remove whitespace added here, and thus will fail to concatenate
  28    the tokens.  */
  29 #define MY(OP) CONCAT2 (i386_aout_lynx_,OP)
  30 #define TARGETNAME "a.out-i386-lynx"
  31
  32 #include "sysdep.h"
  33 #include "bfd.h"
  34 #include "libbfd.h"
  35
  36 #ifndef WRITE_HEADERS
  37 #define WRITE_HEADERS(abfd, execp)                                            \
  38       {                                                                       \
  39         if (adata(abfd).magic == undecided_magic)                             \
  40           NAME(aout,adjust_sizes_and_vmas) (abfd);                            \
  41                                                                               \
  42         execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;        \
  43         execp->a_entry = bfd_get_start_address (abfd);                        \
  44                                                                               \
  45         execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *                \
  46                            obj_reloc_entry_size (abfd));                      \
  47         execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *                \
  48                            obj_reloc_entry_size (abfd));                      \
  49         NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);           \
  50                                                                               \
  51         if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0                      \
  52             || bfd_bwrite (&exec_bytes, (bfd_size_type) EXEC_BYTES_SIZE, \
  53                           abfd) != EXEC_BYTES_SIZE)                           \
  54           return FALSE;                                                       \
  55         /* Now write out reloc info, followed by syms and strings */          \
  56                                                                               \
  57         if (bfd_get_symcount (abfd) != 0)                                     \
  58             {                                                                 \
  59               if (bfd_seek (abfd, (file_ptr) (N_SYMOFF (execp)), SEEK_SET)    \
  60                   != 0)                                                       \
  61                 return FALSE;                                                 \
  62                                                                               \
  63               if (! NAME(aout,write_syms) (abfd)) return FALSE;               \
  64                                                                               \
  65               if (bfd_seek (abfd, (file_ptr) (N_TRELOFF (execp)), SEEK_SET)   \
  66                   != 0)                                                       \
  67                 return FALSE;                                                 \
  68                                                                               \
  69               if (!NAME(lynx,squirt_out_relocs) (abfd, obj_textsec (abfd)))   \
  70                 return FALSE;                                                 \
  71               if (bfd_seek (abfd, (file_ptr) (N_DRELOFF (execp)), SEEK_SET)   \
  72                   != 0)                                                       \
  73                 return 0;                                                     \
  74                                                                               \
  75               if (!NAME(lynx,squirt_out_relocs) (abfd, obj_datasec (abfd)))   \
  76                 return FALSE;                                                 \
  77             }                                                                 \
  78       }
  79 #endif
  80
  81 #include "libaout.h"
  82 #include "aout/aout64.h"
  83
  84
  85 #ifdef LYNX_CORE
  86
  87 char *lynx_core_file_failing_command ();
  88 int lynx_core_file_failing_signal ();
  89 bfd_boolean lynx_core_file_matches_executable_p ();
  90 const bfd_target *lynx_core_file_p ();
  91
  92 #define MY_core_file_failing_command lynx_core_file_failing_command
  93 #define MY_core_file_failing_signal lynx_core_file_failing_signal
  94 #define MY_core_file_matches_executable_p lynx_core_file_matches_executable_p
  95 #define MY_core_file_p lynx_core_file_p
  96
  97 #endif /* LYNX_CORE */
  98 \f
  99
 100 #define KEEPIT udata.i
 101
 102 extern reloc_howto_type aout_32_ext_howto_table[];
 103 extern reloc_howto_type aout_32_std_howto_table[];
 104
 105 /* Standard reloc stuff */
 106 /* Output standard relocation information to a file in target byte order. */
 107
 108 static void
 109 NAME(lynx,swap_std_reloc_out) (bfd *abfd,
 110                                arelent *g,
 111                                struct reloc_std_external *natptr)
 112 {
 113   int r_index;
 114   asymbol *sym = *(g->sym_ptr_ptr);
 115   int r_extern;
 116   unsigned int r_length;
 117   int r_pcrel;
 118   int r_baserel, r_jmptable, r_relative;
 119   asection *output_section = sym->section->output_section;
 120
 121   PUT_WORD (abfd, g->address, natptr->r_address);
 122
 123   r_length = g->howto->size;    /* Size as a power of two */
 124   r_pcrel = (int) g->howto->pc_relative;        /* Relative to PC? */
 125   /* r_baserel, r_jmptable, r_relative???  FIXME-soon */
 126   r_baserel = 0;
 127   r_jmptable = 0;
 128   r_relative = 0;
 129
 130   /* name was clobbered by aout_write_syms to be symbol index */
 131
 132   /* If this relocation is relative to a symbol then set the
 133      r_index to the symbols index, and the r_extern bit.
 134
 135      Absolute symbols can come in in two ways, either as an offset
 136      from the abs section, or as a symbol which has an abs value.
 137      check for that here
 138   */
 139
 140   if (bfd_is_com_section (output_section)
 141       || bfd_is_abs_section (output_section)
 142       || bfd_is_und_section (output_section))
 143     {
 144       if (bfd_abs_section_ptr->symbol == sym)
 145         {
 146           /* Whoops, looked like an abs symbol, but is really an offset
 147              from the abs section */
 148           r_index = 0;
 149           r_extern = 0;
 150         }
 151       else
 152         {
 153           /* Fill in symbol */
 154           r_extern = 1;
 155           r_index = (*g->sym_ptr_ptr)->KEEPIT;
 156         }
 157     }
 158   else
 159     {
 160       /* Just an ordinary section */
 161       r_extern = 0;
 162       r_index = output_section->target_index;
 163     }
 164
 165   /* now the fun stuff */
 166   if (bfd_header_big_endian (abfd))
 167     {
 168       natptr->r_index[0] = r_index >> 16;
 169       natptr->r_index[1] = r_index >> 8;
 170       natptr->r_index[2] = r_index;
 171       natptr->r_type[0] =
 172         (r_extern ? RELOC_STD_BITS_EXTERN_BIG : 0)
 173         | (r_pcrel ? RELOC_STD_BITS_PCREL_BIG : 0)
 174         | (r_baserel ? RELOC_STD_BITS_BASEREL_BIG : 0)
 175         | (r_jmptable ? RELOC_STD_BITS_JMPTABLE_BIG : 0)
 176         | (r_relative ? RELOC_STD_BITS_RELATIVE_BIG : 0)
 177         | (r_length << RELOC_STD_BITS_LENGTH_SH_BIG);
 178     }
 179   else
 180     {
 181       natptr->r_index[2] = r_index >> 16;
 182       natptr->r_index[1] = r_index >> 8;
 183       natptr->r_index[0] = r_index;
 184       natptr->r_type[0] =
 185         (r_extern ? RELOC_STD_BITS_EXTERN_LITTLE : 0)
 186         | (r_pcrel ? RELOC_STD_BITS_PCREL_LITTLE : 0)
 187         | (r_baserel ? RELOC_STD_BITS_BASEREL_LITTLE : 0)
 188         | (r_jmptable ? RELOC_STD_BITS_JMPTABLE_LITTLE : 0)
 189         | (r_relative ? RELOC_STD_BITS_RELATIVE_LITTLE : 0)
 190         | (r_length << RELOC_STD_BITS_LENGTH_SH_LITTLE);
 191     }
 192 }
 193
 194
 195 /* Extended stuff */
 196 /* Output extended relocation information to a file in target byte order. */
 197
 198 static void
 199 NAME(lynx,swap_ext_reloc_out) (bfd *abfd,
 200                                arelent *g,
 201                                struct reloc_ext_external *natptr)
 202 {
 203   int r_index;
 204   int r_extern;
 205   unsigned int r_type;
 206   unsigned int r_addend;
 207   asymbol *sym = *(g->sym_ptr_ptr);
 208   asection *output_section = sym->section->output_section;
 209
 210   PUT_WORD (abfd, g->address, natptr->r_address);
 211
 212   r_type = (unsigned int) g->howto->type;
 213
 214   r_addend = g->addend + (*(g->sym_ptr_ptr))->section->output_section->vma;
 215
 216
 217   /* If this relocation is relative to a symbol then set the
 218      r_index to the symbols index, and the r_extern bit.
 219
 220      Absolute symbols can come in in two ways, either as an offset
 221      from the abs section, or as a symbol which has an abs value.
 222      check for that here
 223      */
 224
 225   if (bfd_is_com_section (output_section)
 226       || bfd_is_abs_section (output_section)
 227       || bfd_is_und_section (output_section))
 228     {
 229       if (bfd_abs_section_ptr->symbol == sym)
 230         {
 231           /* Whoops, looked like an abs symbol, but is really an offset
 232          from the abs section */
 233           r_index = 0;
 234           r_extern = 0;
 235         }
 236       else
 237         {
 238           r_extern = 1;
 239           r_index = (*g->sym_ptr_ptr)->KEEPIT;
 240         }
 241     }
 242   else
 243     {
 244       /* Just an ordinary section */
 245       r_extern = 0;
 246       r_index = output_section->target_index;
 247     }
 248
 249
 250   /* now the fun stuff */
 251   if (bfd_header_big_endian (abfd))
 252     {
 253       natptr->r_index[0] = r_index >> 16;
 254       natptr->r_index[1] = r_index >> 8;
 255       natptr->r_index[2] = r_index;
 256       natptr->r_type[0] =
 257         (r_extern ? RELOC_EXT_BITS_EXTERN_BIG : 0)
 258         | (r_type << RELOC_EXT_BITS_TYPE_SH_BIG);
 259     }
 260   else
 261     {
 262       natptr->r_index[2] = r_index >> 16;
 263       natptr->r_index[1] = r_index >> 8;
 264       natptr->r_index[0] = r_index;
 265       natptr->r_type[0] =
 266         (r_extern ? RELOC_EXT_BITS_EXTERN_LITTLE : 0)
 267         | (r_type << RELOC_EXT_BITS_TYPE_SH_LITTLE);
 268     }
 269
 270   PUT_WORD (abfd, r_addend, natptr->r_addend);
 271 }
 272
 273 /* BFD deals internally with all things based from the section they're
 274    in. so, something in 10 bytes into a text section  with a base of
 275    50 would have a symbol (.text+10) and know .text vma was 50.
 276
 277    Aout keeps all it's symbols based from zero, so the symbol would
 278    contain 60. This macro subs the base of each section from the value
 279    to give the true offset from the section */
 280
 281
 282 #define MOVE_ADDRESS(ad)                                                \
 283   if (r_extern)                                                         \
 284     {                                                                   \
 285    /* undefined symbol */                                               \
 286      cache_ptr->sym_ptr_ptr = symbols + r_index;                        \
 287      cache_ptr->addend = ad;                                            \
 288     }                                                                   \
 289   else                                                                  \
 290     {                                                                   \
 291     /* defined, section relative. replace symbol with pointer to        \
 292        symbol which points to section  */                               \
 293     switch (r_index) {                                                  \
 294     case N_TEXT:                                                        \
 295     case N_TEXT | N_EXT:                                                \
 296       cache_ptr->sym_ptr_ptr  = obj_textsec(abfd)->symbol_ptr_ptr;      \
 297       cache_ptr->addend = ad  - su->textsec->vma;                       \
 298       break;                                                            \
 299     case N_DATA:                                                        \
 300     case N_DATA | N_EXT:                                                \
 301       cache_ptr->sym_ptr_ptr  = obj_datasec(abfd)->symbol_ptr_ptr;      \
 302       cache_ptr->addend = ad - su->datasec->vma;                        \
 303       break;                                                            \
 304     case N_BSS:                                                         \
 305     case N_BSS | N_EXT:                                                 \
 306       cache_ptr->sym_ptr_ptr  = obj_bsssec(abfd)->symbol_ptr_ptr;       \
 307       cache_ptr->addend = ad - su->bsssec->vma;                         \
 308       break;                                                            \
 309     default:                                                            \
 310     case N_ABS:                                                         \
 311     case N_ABS | N_EXT:                                                 \
 312      cache_ptr->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;      \
 313       cache_ptr->addend = ad;                                           \
 314       break;                                                            \
 315     }                                                                   \
 316   }                                                                     \
 317
 318 static void
 319 NAME(lynx,swap_ext_reloc_in) (bfd *abfd,
 320                               struct reloc_ext_external *bytes,
 321                               arelent *cache_ptr,
 322                               asymbol **symbols,
 323                               bfd_size_type symcount ATTRIBUTE_UNUSED)
 324 {
 325   int r_index;
 326   int r_extern;
 327   unsigned int r_type;
 328   struct aoutdata *su = &(abfd->tdata.aout_data->a);
 329
 330   cache_ptr->address = (GET_SWORD (abfd, bytes->r_address));
 331
 332   r_index = bytes->r_index[1];
 333   r_extern = (0 != (bytes->r_index[0] & RELOC_EXT_BITS_EXTERN_BIG));
 334   r_type = (bytes->r_index[0] & RELOC_EXT_BITS_TYPE_BIG)
 335     >> RELOC_EXT_BITS_TYPE_SH_BIG;
 336
 337   cache_ptr->howto = aout_32_ext_howto_table + r_type;
 338   MOVE_ADDRESS (GET_SWORD (abfd, bytes->r_addend));
 339 }
 340
 341 static void
 342 NAME(lynx,swap_std_reloc_in) (bfd *abfd,
 343                               struct reloc_std_external *bytes,
 344                               arelent *cache_ptr,
 345                               asymbol **symbols,
 346                               bfd_size_type symcount ATTRIBUTE_UNUSED)
 347 {
 348   int r_index;
 349   int r_extern;
 350   unsigned int r_length;
 351   int r_pcrel;
 352   struct aoutdata *su = &(abfd->tdata.aout_data->a);
 353
 354   cache_ptr->address = H_GET_32 (abfd, bytes->r_address);
 355
 356   r_index = bytes->r_index[1];
 357   r_extern = (0 != (bytes->r_index[0] & RELOC_STD_BITS_EXTERN_BIG));
 358   r_pcrel = (0 != (bytes->r_index[0] & RELOC_STD_BITS_PCREL_BIG));
 359   r_length = (bytes->r_index[0] & RELOC_STD_BITS_LENGTH_BIG)
 360     >> RELOC_STD_BITS_LENGTH_SH_BIG;
 361
 362   cache_ptr->howto = aout_32_std_howto_table + r_length + 4 * r_pcrel;
 363   /* FIXME-soon:  Roll baserel, jmptable, relative bits into howto setting */
 364
 365   MOVE_ADDRESS (0);
 366 }
 367
 368 /* Reloc hackery */
 369
 370 static bfd_boolean
 371 NAME(lynx,slurp_reloc_table) (bfd *abfd,
 372                               sec_ptr asect,
 373                               asymbol **symbols)
 374 {
 375   bfd_size_type count;
 376   bfd_size_type reloc_size;
 377   void * relocs;
 378   arelent *reloc_cache;
 379   size_t each_size;
 380
 381   if (asect->relocation)
 382     return TRUE;
 383
 384   if (asect->flags & SEC_CONSTRUCTOR)
 385     return TRUE;
 386
 387   if (asect == obj_datasec (abfd))
 388     {
 389       reloc_size = exec_hdr (abfd)->a_drsize;
 390       goto doit;
 391     }
 392
 393   if (asect == obj_textsec (abfd))
 394     {
 395       reloc_size = exec_hdr (abfd)->a_trsize;
 396       goto doit;
 397     }
 398
 399   bfd_set_error (bfd_error_invalid_operation);
 400   return FALSE;
 401
 402 doit:
 403   if (bfd_seek (abfd, asect->rel_filepos, SEEK_SET) != 0)
 404     return FALSE;
 405   each_size = obj_reloc_entry_size (abfd);
 406
 407   count = reloc_size / each_size;
 408
 409
 410   reloc_cache = (arelent *) bfd_zmalloc (count * sizeof (arelent));
 411   if (!reloc_cache && count != 0)
 412     return FALSE;
 413
 414   relocs = bfd_alloc (abfd, reloc_size);
 415   if (!relocs && reloc_size != 0)
 416     {
 417       free (reloc_cache);
 418       return FALSE;
 419     }
 420
 421   if (bfd_bread (relocs, reloc_size, abfd) != reloc_size)
 422     {
 423       bfd_release (abfd, relocs);
 424       free (reloc_cache);
 425       return FALSE;
 426     }
 427
 428   if (each_size == RELOC_EXT_SIZE)
 429     {
 430       struct reloc_ext_external *rptr = (struct reloc_ext_external *) relocs;
 431       unsigned int counter = 0;
 432       arelent *cache_ptr = reloc_cache;
 433
 434       for (; counter < count; counter++, rptr++, cache_ptr++)
 435         {
 436           NAME(lynx,swap_ext_reloc_in) (abfd, rptr, cache_ptr, symbols,
 437                                         (bfd_size_type) bfd_get_symcount (abfd));
 438         }
 439     }
 440   else
 441     {
 442       struct reloc_std_external *rptr = (struct reloc_std_external *) relocs;
 443       unsigned int counter = 0;
 444       arelent *cache_ptr = reloc_cache;
 445
 446       for (; counter < count; counter++, rptr++, cache_ptr++)
 447         {
 448           NAME(lynx,swap_std_reloc_in) (abfd, rptr, cache_ptr, symbols,
 449                                         (bfd_size_type) bfd_get_symcount (abfd));
 450         }
 451
 452     }
 453
 454   bfd_release (abfd, relocs);
 455   asect->relocation = reloc_cache;
 456   asect->reloc_count = count;
 457   return TRUE;
 458 }
 459
 460
 461
 462 /* Write out a relocation section into an object file.  */
 463
 464 static bfd_boolean
 465 NAME(lynx,squirt_out_relocs) (bfd *abfd, asection *section)
 466 {
 467   arelent **generic;
 468   unsigned char *native, *natptr;
 469   size_t each_size;
 470   unsigned int count = section->reloc_count;
 471   bfd_size_type natsize;
 472
 473   if (count == 0)
 474     return TRUE;
 475
 476   each_size = obj_reloc_entry_size (abfd);
 477   natsize = count;
 478   natsize *= each_size;
 479   native = (unsigned char *) bfd_zalloc (abfd, natsize);
 480   if (!native)
 481     return FALSE;
 482
 483   generic = section->orelocation;
 484
 485   if (each_size == RELOC_EXT_SIZE)
 486     {
 487       for (natptr = native;
 488            count != 0;
 489            --count, natptr += each_size, ++generic)
 490         NAME(lynx,swap_ext_reloc_out) (abfd, *generic, (struct reloc_ext_external *) natptr);
 491     }
 492   else
 493     {
 494       for (natptr = native;
 495            count != 0;
 496            --count, natptr += each_size, ++generic)
 497         NAME(lynx,swap_std_reloc_out) (abfd, *generic, (struct reloc_std_external *) natptr);
 498     }
 499
 500   if (bfd_bwrite (native, natsize, abfd) != natsize)
 501     {
 502       bfd_release (abfd, native);
 503       return FALSE;
 504     }
 505   bfd_release (abfd, native);
 506
 507   return TRUE;
 508 }
 509
 510 /* This is stupid.  This function should be a boolean predicate */
 511 static long
 512 NAME(lynx,canonicalize_reloc) (bfd *abfd,
 513                                sec_ptr section,
 514                                arelent **relptr,
 515                                asymbol **symbols)
 516 {
 517   arelent *tblptr = section->relocation;
 518   unsigned int count;
 519
 520   if (!(tblptr || NAME(lynx,slurp_reloc_table) (abfd, section, symbols)))
 521     return -1;
 522
 523   if (section->flags & SEC_CONSTRUCTOR)
 524     {
 525       arelent_chain *chain = section->constructor_chain;
 526       for (count = 0; count < section->reloc_count; count++)
 527         {
 528           *relptr++ = &chain->relent;
 529           chain = chain->next;
 530         }
 531     }
 532   else
 533     {
 534       tblptr = section->relocation;
 535
 536       for (count = 0; count++ < section->reloc_count;)
 537         {
 538           *relptr++ = tblptr++;
 539         }
 540     }
 541   *relptr = 0;
 542
 543   return section->reloc_count;
 544 }
 545
 546 #define MY_canonicalize_reloc NAME(lynx,canonicalize_reloc)
 547
 548 #include "aout-target.h"