1 /* BFD back-end for Motorola 68000 COFF binaries. 2 Copyright (C) 1990-2014 Free Software Foundation, Inc. 3 Written by Cygnus Support. 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 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, write to the Free Software 19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 20 MA 02110-1301, USA. */ 21 22 #include "sysdep.h" 23 #include "bfd.h" 24 #include "libbfd.h" 25 #include "coff/m68k.h" 26 #include "coff/internal.h" 27 #include "libcoff.h" 28 29 /* This source file is compiled multiple times for various m68k COFF 30 variants. The following macros control its behaviour: 31 32 TARGET_SYM 33 The C name of the BFD target vector. The default is m68k_coff_vec. 34 TARGET_NAME 35 The user visible target name. The default is "coff-m68k". 36 NAMES_HAVE_UNDERSCORE 37 Whether symbol names have an underscore. 38 ONLY_DECLARE_RELOCS 39 Only declare the relocation howto array. Don't actually compile 40 it. The actual array will be picked up in another version of the 41 file. 42 STATIC_RELOCS 43 Make the relocation howto array, and associated functions, static. 44 COFF_COMMON_ADDEND 45 If this is defined, then, for a relocation against a common 46 symbol, the object file holds the value (the size) of the common 47 symbol. If this is not defined, then, for a relocation against a 48 common symbol, the object file holds zero. */ 49 50 #define COFF_DEFAULT_SECTION_ALIGNMENT_POWER (2) 51 52 #ifndef COFF_PAGE_SIZE 53 /* The page size is a guess based on ELF. */ 54 #define COFF_PAGE_SIZE 0x2000 55 #endif 56 57 #ifndef COFF_COMMON_ADDEND 58 #define RELOC_SPECIAL_FN 0 59 #else 60 static bfd_reloc_status_type m68kcoff_common_addend_special_fn 61 (bfd *, arelent *, asymbol *, void *, asection *, bfd *, char **); 62 63 #define RELOC_SPECIAL_FN m68kcoff_common_addend_special_fn 64 #endif 65 66 static bfd_boolean m68k_coff_is_local_label_name (bfd *, const char *); 67 68 /* On the delta, a symbol starting with L% is local. We won't see 69 such a symbol on other platforms, so it should be safe to always 70 consider it local here. */ 71 72 static bfd_boolean 73 m68k_coff_is_local_label_name (bfd *abfd, const char *name) 74 { 75 if (name[0] == 'L' && name[1] == '%') 76 return TRUE; 77 78 return _bfd_coff_is_local_label_name (abfd, name); 79 } 80 81 #ifndef STATIC_RELOCS 82 /* Clean up namespace. */ 83 #define m68kcoff_howto_table _bfd_m68kcoff_howto_table 84 #define m68k_rtype2howto _bfd_m68kcoff_rtype2howto 85 #define m68k_howto2rtype _bfd_m68kcoff_howto2rtype 86 #define m68k_reloc_type_lookup _bfd_m68kcoff_reloc_type_lookup 87 #define m68k_reloc_name_lookup _bfd_m68kcoff_reloc_name_lookup 88 #endif 89 90 #ifdef ONLY_DECLARE_RELOCS 91 extern reloc_howto_type m68kcoff_howto_table[]; 92 #else 93 #ifdef STATIC_RELOCS 94 static 95 #endif 96 reloc_howto_type m68kcoff_howto_table[] = 97 { 98 HOWTO (R_RELBYTE, 0, 0, 8, FALSE, 0, complain_overflow_bitfield, RELOC_SPECIAL_FN, "8", TRUE, 0x000000ff,0x000000ff, FALSE), 99 HOWTO (R_RELWORD, 0, 1, 16, FALSE, 0, complain_overflow_bitfield, RELOC_SPECIAL_FN, "16", TRUE, 0x0000ffff,0x0000ffff, FALSE), 100 HOWTO (R_RELLONG, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, RELOC_SPECIAL_FN, "32", TRUE, 0xffffffff,0xffffffff, FALSE), 101 HOWTO (R_PCRBYTE, 0, 0, 8, TRUE, 0, complain_overflow_signed, RELOC_SPECIAL_FN, "DISP8", TRUE, 0x000000ff,0x000000ff, FALSE), 102 HOWTO (R_PCRWORD, 0, 1, 16, TRUE, 0, complain_overflow_signed, RELOC_SPECIAL_FN, "DISP16", TRUE, 0x0000ffff,0x0000ffff, FALSE), 103 HOWTO (R_PCRLONG, 0, 2, 32, TRUE, 0, complain_overflow_signed, RELOC_SPECIAL_FN, "DISP32", TRUE, 0xffffffff,0xffffffff, FALSE), 104 HOWTO (R_RELLONG_NEG, 0, -2, 32, FALSE, 0, complain_overflow_bitfield, RELOC_SPECIAL_FN, "-32", TRUE, 0xffffffff,0xffffffff, FALSE), 105 }; 106 #endif /* not ONLY_DECLARE_RELOCS */ 107 108 #ifndef BADMAG 109 #define BADMAG(x) M68KBADMAG(x) 110 #endif 111 #define M68 1 /* Customize coffcode.h */ 112 113 /* Turn a howto into a reloc number */ 114 115 #ifdef ONLY_DECLARE_RELOCS 116 extern void m68k_rtype2howto (arelent *internal, int relocentry); 117 extern int m68k_howto2rtype (reloc_howto_type *); 118 extern reloc_howto_type * m68k_reloc_type_lookup 119 (bfd *, bfd_reloc_code_real_type); 120 extern reloc_howto_type * m68k_reloc_name_lookup (bfd *, const char *); 121 #else 122 123 #ifdef STATIC_RELOCS 124 #define STAT_REL static 125 #else 126 #define STAT_REL 127 #endif 128 129 STAT_REL void m68k_rtype2howto (arelent *, int); 130 STAT_REL int m68k_howto2rtype (reloc_howto_type *); 131 STAT_REL reloc_howto_type * m68k_reloc_type_lookup (bfd *, bfd_reloc_code_real_type); 132 STAT_REL reloc_howto_type * m68k_reloc_name_lookup (bfd *, const char *); 133 134 STAT_REL void 135 m68k_rtype2howto (arelent *internal, int relocentry) 136 { 137 switch (relocentry) 138 { 139 case R_RELBYTE: internal->howto = m68kcoff_howto_table + 0; break; 140 case R_RELWORD: internal->howto = m68kcoff_howto_table + 1; break; 141 case R_RELLONG: internal->howto = m68kcoff_howto_table + 2; break; 142 case R_PCRBYTE: internal->howto = m68kcoff_howto_table + 3; break; 143 case R_PCRWORD: internal->howto = m68kcoff_howto_table + 4; break; 144 case R_PCRLONG: internal->howto = m68kcoff_howto_table + 5; break; 145 case R_RELLONG_NEG: internal->howto = m68kcoff_howto_table + 6; break; 146 } 147 } 148 149 STAT_REL int 150 m68k_howto2rtype (reloc_howto_type * internal) 151 { 152 if (internal->pc_relative) 153 { 154 switch (internal->bitsize) 155 { 156 case 32: return R_PCRLONG; 157 case 16: return R_PCRWORD; 158 case 8: return R_PCRBYTE; 159 } 160 } 161 else 162 { 163 switch (internal->bitsize) 164 { 165 case 32: return R_RELLONG; 166 case 16: return R_RELWORD; 167 case 8: return R_RELBYTE; 168 } 169 } 170 return R_RELLONG; 171 } 172 173 STAT_REL reloc_howto_type * 174 m68k_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED, 175 bfd_reloc_code_real_type code) 176 { 177 switch (code) 178 { 179 default: return NULL; 180 case BFD_RELOC_8: return m68kcoff_howto_table + 0; 181 case BFD_RELOC_16: return m68kcoff_howto_table + 1; 182 case BFD_RELOC_CTOR: 183 case BFD_RELOC_32: return m68kcoff_howto_table + 2; 184 case BFD_RELOC_8_PCREL: return m68kcoff_howto_table + 3; 185 case BFD_RELOC_16_PCREL: return m68kcoff_howto_table + 4; 186 case BFD_RELOC_32_PCREL: return m68kcoff_howto_table + 5; 187 /* FIXME: There doesn't seem to be a code for R_RELLONG_NEG. */ 188 } 189 /*NOTREACHED*/ 190 } 191 192 STAT_REL reloc_howto_type * 193 m68k_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, 194 const char *r_name) 195 { 196 unsigned int i; 197 198 for (i = 0; 199 i < sizeof (m68kcoff_howto_table) / sizeof (m68kcoff_howto_table[0]); 200 i++) 201 if (m68kcoff_howto_table[i].name != NULL 202 && strcasecmp (m68kcoff_howto_table[i].name, r_name) == 0) 203 return &m68kcoff_howto_table[i]; 204 205 return NULL; 206 } 207 208 #endif /* not ONLY_DECLARE_RELOCS */ 209 210 #define RTYPE2HOWTO(internal, relocentry) \ 211 m68k_rtype2howto(internal, (relocentry)->r_type) 212 213 #define SELECT_RELOC(external, internal) \ 214 external.r_type = m68k_howto2rtype (internal) 215 216 #define coff_bfd_reloc_type_lookup m68k_reloc_type_lookup 217 #define coff_bfd_reloc_name_lookup m68k_reloc_name_lookup 218 219 #ifndef COFF_COMMON_ADDEND 220 #ifndef coff_rtype_to_howto 221 222 #define coff_rtype_to_howto m68kcoff_rtype_to_howto 223 224 static reloc_howto_type * 225 m68kcoff_rtype_to_howto (bfd *abfd ATTRIBUTE_UNUSED, 226 asection *sec, 227 struct internal_reloc *rel, 228 struct coff_link_hash_entry *h ATTRIBUTE_UNUSED, 229 struct internal_syment *sym ATTRIBUTE_UNUSED, 230 bfd_vma *addendp) 231 { 232 arelent relent; 233 reloc_howto_type *howto; 234 235 relent.howto = NULL; 236 RTYPE2HOWTO (&relent, rel); 237 238 howto = relent.howto; 239 240 if (howto != NULL && howto->pc_relative) 241 *addendp += sec->vma; 242 243 return howto; 244 } 245 246 #endif /* ! defined (coff_rtype_to_howto) */ 247 #endif /* ! defined (COFF_COMMON_ADDEND) */ 248 249 #ifdef COFF_COMMON_ADDEND 251 252 /* If COFF_COMMON_ADDEND is defined, then when using m68k COFF the 253 value stored in the .text section for a reference to a common 254 symbol is the value itself plus any desired offset. (taken from 255 work done by Ian Taylor, Cygnus Support, for I386 COFF). */ 256 257 /* If we are producing relocatable output, we need to do some 258 adjustments to the object file that are not done by the 259 bfd_perform_relocation function. This function is called by every 260 reloc type to make any required adjustments. */ 261 262 static bfd_reloc_status_type 263 m68kcoff_common_addend_special_fn (bfd *abfd, 264 arelent *reloc_entry, 265 asymbol *symbol, 266 void * data, 267 asection *input_section ATTRIBUTE_UNUSED, 268 bfd *output_bfd, 269 char **error_message ATTRIBUTE_UNUSED) 270 { 271 symvalue diff; 272 273 if (output_bfd == (bfd *) NULL) 274 return bfd_reloc_continue; 275 276 if (bfd_is_com_section (symbol->section)) 277 { 278 /* We are relocating a common symbol. The current value in the 279 object file is ORIG + OFFSET, where ORIG is the value of the 280 common symbol as seen by the object file when it was compiled 281 (this may be zero if the symbol was undefined) and OFFSET is 282 the offset into the common symbol (normally zero, but may be 283 non-zero when referring to a field in a common structure). 284 ORIG is the negative of reloc_entry->addend, which is set by 285 the CALC_ADDEND macro below. We want to replace the value in 286 the object file with NEW + OFFSET, where NEW is the value of 287 the common symbol which we are going to put in the final 288 object file. NEW is symbol->value. */ 289 diff = symbol->value + reloc_entry->addend; 290 } 291 else 292 { 293 /* For some reason bfd_perform_relocation always effectively 294 ignores the addend for a COFF target when producing 295 relocatable output. This seems to be always wrong for 386 296 COFF, so we handle the addend here instead. */ 297 diff = reloc_entry->addend; 298 } 299 300 #define DOIT(x) \ 301 x = ((x & ~howto->dst_mask) | (((x & howto->src_mask) + diff) & howto->dst_mask)) 302 303 if (diff != 0) 304 { 305 reloc_howto_type *howto = reloc_entry->howto; 306 unsigned char *addr = (unsigned char *) data + reloc_entry->address; 307 308 switch (howto->size) 309 { 310 case 0: 311 { 312 char x = bfd_get_8 (abfd, addr); 313 DOIT (x); 314 bfd_put_8 (abfd, x, addr); 315 } 316 break; 317 318 case 1: 319 { 320 short x = bfd_get_16 (abfd, addr); 321 DOIT (x); 322 bfd_put_16 (abfd, (bfd_vma) x, addr); 323 } 324 break; 325 326 case 2: 327 { 328 long x = bfd_get_32 (abfd, addr); 329 DOIT (x); 330 bfd_put_32 (abfd, (bfd_vma) x, addr); 331 } 332 break; 333 334 default: 335 abort (); 336 } 337 } 338 339 /* Now let bfd_perform_relocation finish everything up. */ 340 return bfd_reloc_continue; 341 } 342 343 /* Compute the addend of a reloc. If the reloc is to a common symbol, 344 the object file contains the value of the common symbol. By the 345 time this is called, the linker may be using a different symbol 346 from a different object file with a different value. Therefore, we 347 hack wildly to locate the original symbol from this file so that we 348 can make the correct adjustment. This macro sets coffsym to the 349 symbol from the original file, and uses it to set the addend value 350 correctly. If this is not a common symbol, the usual addend 351 calculation is done, except that an additional tweak is needed for 352 PC relative relocs. 353 FIXME: This macro refers to symbols and asect; these are from the 354 calling function, not the macro arguments. */ 355 356 #define CALC_ADDEND(abfd, ptr, reloc, cache_ptr) \ 357 { \ 358 coff_symbol_type *coffsym = (coff_symbol_type *) NULL; \ 359 if (ptr && bfd_asymbol_bfd (ptr) != abfd) \ 360 coffsym = (obj_symbols (abfd) \ 361 + (cache_ptr->sym_ptr_ptr - symbols)); \ 362 else if (ptr) \ 363 coffsym = coff_symbol_from (abfd, ptr); \ 364 if (coffsym != (coff_symbol_type *) NULL \ 365 && coffsym->native->u.syment.n_scnum == 0) \ 366 cache_ptr->addend = - coffsym->native->u.syment.n_value; \ 367 else if (ptr && bfd_asymbol_bfd (ptr) == abfd \ 368 && ptr->section != (asection *) NULL) \ 369 cache_ptr->addend = - (ptr->section->vma + ptr->value); \ 370 else \ 371 cache_ptr->addend = 0; \ 372 if (ptr && (reloc.r_type == R_PCRBYTE \ 373 || reloc.r_type == R_PCRWORD \ 374 || reloc.r_type == R_PCRLONG)) \ 375 cache_ptr->addend += asect->vma; \ 376 } 377 378 #ifndef coff_rtype_to_howto 379 380 /* coff-m68k.c uses the special COFF backend linker. We need to 381 adjust common symbols. */ 382 383 static reloc_howto_type * 384 m68kcoff_common_addend_rtype_to_howto (bfd *abfd ATTRIBUTE_UNUSED, 385 asection *sec, 386 struct internal_reloc *rel, 387 struct coff_link_hash_entry *h, 388 struct internal_syment *sym, 389 bfd_vma *addendp) 390 { 391 arelent relent; 392 reloc_howto_type *howto; 393 394 relent.howto = NULL; 395 RTYPE2HOWTO (&relent, rel); 396 397 howto = relent.howto; 398 399 if (howto->pc_relative) 400 *addendp += sec->vma; 401 402 if (sym != NULL && sym->n_scnum == 0 && sym->n_value != 0) 403 { 404 /* This is a common symbol. The section contents include the 405 size (sym->n_value) as an addend. The relocate_section 406 function will be adding in the final value of the symbol. We 407 need to subtract out the current size in order to get the 408 correct result. */ 409 BFD_ASSERT (h != NULL); 410 *addendp -= sym->n_value; 411 } 412 413 /* If the output symbol is common (in which case this must be a 414 relocatable link), we need to add in the final size of the 415 common symbol. */ 416 if (h != NULL && h->root.type == bfd_link_hash_common) 417 *addendp += h->root.u.c.size; 418 419 return howto; 420 } 421 422 #define coff_rtype_to_howto m68kcoff_common_addend_rtype_to_howto 423 424 #endif /* ! defined (coff_rtype_to_howto) */ 425 426 #endif /* COFF_COMMON_ADDEND */ 427 428 #if !defined ONLY_DECLARE_RELOCS && ! defined STATIC_RELOCS 429 /* Given a .data section and a .emreloc in-memory section, store 430 relocation information into the .emreloc section which can be 431 used at runtime to relocate the section. This is called by the 432 linker when the --embedded-relocs switch is used. This is called 433 after the add_symbols entry point has been called for all the 434 objects, and before the final_link entry point is called. */ 435 436 bfd_boolean 437 bfd_m68k_coff_create_embedded_relocs (bfd *abfd, 438 struct bfd_link_info *info, 439 asection *datasec, 440 asection *relsec, 441 char **errmsg) 442 { 443 char *extsyms; 444 bfd_size_type symesz; 445 struct internal_reloc *irel, *irelend; 446 bfd_byte *p; 447 bfd_size_type amt; 448 449 BFD_ASSERT (! info->relocatable); 450 451 *errmsg = NULL; 452 453 if (datasec->reloc_count == 0) 454 return TRUE; 455 456 extsyms = obj_coff_external_syms (abfd); 457 symesz = bfd_coff_symesz (abfd); 458 459 irel = _bfd_coff_read_internal_relocs (abfd, datasec, TRUE, NULL, FALSE, 460 NULL); 461 irelend = irel + datasec->reloc_count; 462 463 amt = (bfd_size_type) datasec->reloc_count * 12; 464 relsec->contents = (bfd_byte *) bfd_alloc (abfd, amt); 465 if (relsec->contents == NULL) 466 return FALSE; 467 468 p = relsec->contents; 469 470 for (; irel < irelend; irel++, p += 12) 471 { 472 asection *targetsec; 473 474 /* We are going to write a four byte longword into the runtime 475 reloc section. The longword will be the address in the data 476 section which must be relocated. It is followed by the name 477 of the target section NUL-padded or truncated to 8 478 characters. */ 479 480 /* We can only relocate absolute longword relocs at run time. */ 481 if (irel->r_type != R_RELLONG) 482 { 483 *errmsg = _("unsupported reloc type"); 484 bfd_set_error (bfd_error_bad_value); 485 return FALSE; 486 } 487 488 if (irel->r_symndx == -1) 489 targetsec = bfd_abs_section_ptr; 490 else 491 { 492 struct coff_link_hash_entry *h; 493 494 h = obj_coff_sym_hashes (abfd)[irel->r_symndx]; 495 if (h == NULL) 496 { 497 struct internal_syment isym; 498 499 bfd_coff_swap_sym_in (abfd, extsyms + symesz * irel->r_symndx, 500 &isym); 501 targetsec = coff_section_from_bfd_index (abfd, isym.n_scnum); 502 } 503 else if (h->root.type == bfd_link_hash_defined 504 || h->root.type == bfd_link_hash_defweak) 505 targetsec = h->root.u.def.section; 506 else 507 targetsec = NULL; 508 } 509 510 bfd_put_32 (abfd, 511 (irel->r_vaddr - datasec->vma + datasec->output_offset), p); 512 memset (p + 4, 0, 8); 513 if (targetsec != NULL) 514 strncpy ((char *) p + 4, targetsec->output_section->name, 8); 515 } 516 517 return TRUE; 518 } 519 #endif /* neither ONLY_DECLARE_RELOCS not STATIC_RELOCS */ 520 521 #define coff_bfd_is_local_label_name m68k_coff_is_local_label_name 523 524 #define coff_relocate_section _bfd_coff_generic_relocate_section 525 526 #ifndef bfd_pe_print_pdata 527 #define bfd_pe_print_pdata NULL 528 #endif 529 530 #include "coffcode.h" 531 532 #ifndef TARGET_SYM 533 #define TARGET_SYM m68k_coff_vec 534 #endif 535 536 #ifndef TARGET_NAME 537 #define TARGET_NAME "coff-m68k" 538 #endif 539 540 #ifdef NAMES_HAVE_UNDERSCORE 541 CREATE_BIG_COFF_TARGET_VEC (TARGET_SYM, TARGET_NAME, D_PAGED, 0, '_', NULL, COFF_SWAP_TABLE) 542 #else 543 CREATE_BIG_COFF_TARGET_VEC (TARGET_SYM, TARGET_NAME, D_PAGED, 0, 0, NULL, COFF_SWAP_TABLE) 544 #endif 545
