1 /* BFD back-end for Motorola 68000 COFF binaries. 2 Copyright (C) 1990-2016 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 default: internal->howto = NULL; break; 147 } 148 } 149 150 STAT_REL int 151 m68k_howto2rtype (reloc_howto_type * internal) 152 { 153 if (internal->pc_relative) 154 { 155 switch (internal->bitsize) 156 { 157 case 32: return R_PCRLONG; 158 case 16: return R_PCRWORD; 159 case 8: return R_PCRBYTE; 160 } 161 } 162 else 163 { 164 switch (internal->bitsize) 165 { 166 case 32: return R_RELLONG; 167 case 16: return R_RELWORD; 168 case 8: return R_RELBYTE; 169 } 170 } 171 return R_RELLONG; 172 } 173 174 STAT_REL reloc_howto_type * 175 m68k_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED, 176 bfd_reloc_code_real_type code) 177 { 178 switch (code) 179 { 180 default: return NULL; 181 case BFD_RELOC_8: return m68kcoff_howto_table + 0; 182 case BFD_RELOC_16: return m68kcoff_howto_table + 1; 183 case BFD_RELOC_CTOR: 184 case BFD_RELOC_32: return m68kcoff_howto_table + 2; 185 case BFD_RELOC_8_PCREL: return m68kcoff_howto_table + 3; 186 case BFD_RELOC_16_PCREL: return m68kcoff_howto_table + 4; 187 case BFD_RELOC_32_PCREL: return m68kcoff_howto_table + 5; 188 /* FIXME: There doesn't seem to be a code for R_RELLONG_NEG. */ 189 } 190 /*NOTREACHED*/ 191 } 192 193 STAT_REL reloc_howto_type * 194 m68k_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, 195 const char *r_name) 196 { 197 unsigned int i; 198 199 for (i = 0; 200 i < sizeof (m68kcoff_howto_table) / sizeof (m68kcoff_howto_table[0]); 201 i++) 202 if (m68kcoff_howto_table[i].name != NULL 203 && strcasecmp (m68kcoff_howto_table[i].name, r_name) == 0) 204 return &m68kcoff_howto_table[i]; 205 206 return NULL; 207 } 208 209 #endif /* not ONLY_DECLARE_RELOCS */ 210 211 #define RTYPE2HOWTO(internal, relocentry) \ 212 m68k_rtype2howto(internal, (relocentry)->r_type) 213 214 #define SELECT_RELOC(external, internal) \ 215 external.r_type = m68k_howto2rtype (internal) 216 217 #define coff_bfd_reloc_type_lookup m68k_reloc_type_lookup 218 #define coff_bfd_reloc_name_lookup m68k_reloc_name_lookup 219 220 #ifndef COFF_COMMON_ADDEND 221 #ifndef coff_rtype_to_howto 222 223 #define coff_rtype_to_howto m68kcoff_rtype_to_howto 224 225 static reloc_howto_type * 226 m68kcoff_rtype_to_howto (bfd *abfd ATTRIBUTE_UNUSED, 227 asection *sec, 228 struct internal_reloc *rel, 229 struct coff_link_hash_entry *h ATTRIBUTE_UNUSED, 230 struct internal_syment *sym ATTRIBUTE_UNUSED, 231 bfd_vma *addendp) 232 { 233 arelent relent; 234 reloc_howto_type *howto; 235 236 relent.howto = NULL; 237 RTYPE2HOWTO (&relent, rel); 238 239 howto = relent.howto; 240 241 if (howto != NULL && howto->pc_relative) 242 *addendp += sec->vma; 243 244 return howto; 245 } 246 247 #endif /* ! defined (coff_rtype_to_howto) */ 248 #endif /* ! defined (COFF_COMMON_ADDEND) */ 249 250 #ifdef COFF_COMMON_ADDEND 252 253 /* If COFF_COMMON_ADDEND is defined, then when using m68k COFF the 254 value stored in the .text section for a reference to a common 255 symbol is the value itself plus any desired offset. (taken from 256 work done by Ian Taylor, Cygnus Support, for I386 COFF). */ 257 258 /* If we are producing relocatable output, we need to do some 259 adjustments to the object file that are not done by the 260 bfd_perform_relocation function. This function is called by every 261 reloc type to make any required adjustments. */ 262 263 static bfd_reloc_status_type 264 m68kcoff_common_addend_special_fn (bfd *abfd, 265 arelent *reloc_entry, 266 asymbol *symbol, 267 void * data, 268 asection *input_section ATTRIBUTE_UNUSED, 269 bfd *output_bfd, 270 char **error_message ATTRIBUTE_UNUSED) 271 { 272 symvalue diff; 273 274 if (output_bfd == (bfd *) NULL) 275 return bfd_reloc_continue; 276 277 if (bfd_is_com_section (symbol->section)) 278 { 279 /* We are relocating a common symbol. The current value in the 280 object file is ORIG + OFFSET, where ORIG is the value of the 281 common symbol as seen by the object file when it was compiled 282 (this may be zero if the symbol was undefined) and OFFSET is 283 the offset into the common symbol (normally zero, but may be 284 non-zero when referring to a field in a common structure). 285 ORIG is the negative of reloc_entry->addend, which is set by 286 the CALC_ADDEND macro below. We want to replace the value in 287 the object file with NEW + OFFSET, where NEW is the value of 288 the common symbol which we are going to put in the final 289 object file. NEW is symbol->value. */ 290 diff = symbol->value + reloc_entry->addend; 291 } 292 else 293 { 294 /* For some reason bfd_perform_relocation always effectively 295 ignores the addend for a COFF target when producing 296 relocatable output. This seems to be always wrong for 386 297 COFF, so we handle the addend here instead. */ 298 diff = reloc_entry->addend; 299 } 300 301 #define DOIT(x) \ 302 x = ((x & ~howto->dst_mask) | (((x & howto->src_mask) + diff) & howto->dst_mask)) 303 304 if (diff != 0) 305 { 306 reloc_howto_type *howto = reloc_entry->howto; 307 unsigned char *addr = (unsigned char *) data + reloc_entry->address; 308 309 switch (howto->size) 310 { 311 case 0: 312 { 313 char x = bfd_get_8 (abfd, addr); 314 DOIT (x); 315 bfd_put_8 (abfd, x, addr); 316 } 317 break; 318 319 case 1: 320 { 321 short x = bfd_get_16 (abfd, addr); 322 DOIT (x); 323 bfd_put_16 (abfd, (bfd_vma) x, addr); 324 } 325 break; 326 327 case 2: 328 { 329 long x = bfd_get_32 (abfd, addr); 330 DOIT (x); 331 bfd_put_32 (abfd, (bfd_vma) x, addr); 332 } 333 break; 334 335 default: 336 abort (); 337 } 338 } 339 340 /* Now let bfd_perform_relocation finish everything up. */ 341 return bfd_reloc_continue; 342 } 343 344 /* Compute the addend of a reloc. If the reloc is to a common symbol, 345 the object file contains the value of the common symbol. By the 346 time this is called, the linker may be using a different symbol 347 from a different object file with a different value. Therefore, we 348 hack wildly to locate the original symbol from this file so that we 349 can make the correct adjustment. This macro sets coffsym to the 350 symbol from the original file, and uses it to set the addend value 351 correctly. If this is not a common symbol, the usual addend 352 calculation is done, except that an additional tweak is needed for 353 PC relative relocs. 354 FIXME: This macro refers to symbols and asect; these are from the 355 calling function, not the macro arguments. */ 356 357 #define CALC_ADDEND(abfd, ptr, reloc, cache_ptr) \ 358 { \ 359 coff_symbol_type *coffsym = (coff_symbol_type *) NULL; \ 360 if (ptr && bfd_asymbol_bfd (ptr) != abfd) \ 361 coffsym = (obj_symbols (abfd) \ 362 + (cache_ptr->sym_ptr_ptr - symbols)); \ 363 else if (ptr) \ 364 coffsym = coff_symbol_from (ptr); \ 365 if (coffsym != (coff_symbol_type *) NULL \ 366 && coffsym->native->u.syment.n_scnum == 0) \ 367 cache_ptr->addend = - coffsym->native->u.syment.n_value; \ 368 else if (ptr && bfd_asymbol_bfd (ptr) == abfd \ 369 && ptr->section != (asection *) NULL) \ 370 cache_ptr->addend = - (ptr->section->vma + ptr->value); \ 371 else \ 372 cache_ptr->addend = 0; \ 373 if (ptr && (reloc.r_type == R_PCRBYTE \ 374 || reloc.r_type == R_PCRWORD \ 375 || reloc.r_type == R_PCRLONG)) \ 376 cache_ptr->addend += asect->vma; \ 377 } 378 379 #ifndef coff_rtype_to_howto 380 381 /* coff-m68k.c uses the special COFF backend linker. We need to 382 adjust common symbols. */ 383 384 static reloc_howto_type * 385 m68kcoff_common_addend_rtype_to_howto (bfd *abfd ATTRIBUTE_UNUSED, 386 asection *sec, 387 struct internal_reloc *rel, 388 struct coff_link_hash_entry *h, 389 struct internal_syment *sym, 390 bfd_vma *addendp) 391 { 392 arelent relent; 393 reloc_howto_type *howto; 394 395 relent.howto = NULL; 396 RTYPE2HOWTO (&relent, rel); 397 398 howto = relent.howto; 399 400 if (howto->pc_relative) 401 *addendp += sec->vma; 402 403 if (sym != NULL && sym->n_scnum == 0 && sym->n_value != 0) 404 { 405 /* This is a common symbol. The section contents include the 406 size (sym->n_value) as an addend. The relocate_section 407 function will be adding in the final value of the symbol. We 408 need to subtract out the current size in order to get the 409 correct result. */ 410 BFD_ASSERT (h != NULL); 411 *addendp -= sym->n_value; 412 } 413 414 /* If the output symbol is common (in which case this must be a 415 relocatable link), we need to add in the final size of the 416 common symbol. */ 417 if (h != NULL && h->root.type == bfd_link_hash_common) 418 *addendp += h->root.u.c.size; 419 420 return howto; 421 } 422 423 #define coff_rtype_to_howto m68kcoff_common_addend_rtype_to_howto 424 425 #endif /* ! defined (coff_rtype_to_howto) */ 426 427 #endif /* COFF_COMMON_ADDEND */ 428 429 #if !defined ONLY_DECLARE_RELOCS && ! defined STATIC_RELOCS 430 /* Given a .data section and a .emreloc in-memory section, store 431 relocation information into the .emreloc section which can be 432 used at runtime to relocate the section. This is called by the 433 linker when the --embedded-relocs switch is used. This is called 434 after the add_symbols entry point has been called for all the 435 objects, and before the final_link entry point is called. */ 436 437 bfd_boolean 438 bfd_m68k_coff_create_embedded_relocs (bfd *abfd, 439 struct bfd_link_info *info, 440 asection *datasec, 441 asection *relsec, 442 char **errmsg) 443 { 444 char *extsyms; 445 bfd_size_type symesz; 446 struct internal_reloc *irel, *irelend; 447 bfd_byte *p; 448 bfd_size_type amt; 449 450 BFD_ASSERT (! bfd_link_relocatable (info)); 451 452 *errmsg = NULL; 453 454 if (datasec->reloc_count == 0) 455 return TRUE; 456 457 extsyms = obj_coff_external_syms (abfd); 458 symesz = bfd_coff_symesz (abfd); 459 460 irel = _bfd_coff_read_internal_relocs (abfd, datasec, TRUE, NULL, FALSE, 461 NULL); 462 irelend = irel + datasec->reloc_count; 463 464 amt = (bfd_size_type) datasec->reloc_count * 12; 465 relsec->contents = (bfd_byte *) bfd_alloc (abfd, amt); 466 if (relsec->contents == NULL) 467 return FALSE; 468 469 p = relsec->contents; 470 471 for (; irel < irelend; irel++, p += 12) 472 { 473 asection *targetsec; 474 475 /* We are going to write a four byte longword into the runtime 476 reloc section. The longword will be the address in the data 477 section which must be relocated. It is followed by the name 478 of the target section NUL-padded or truncated to 8 479 characters. */ 480 481 /* We can only relocate absolute longword relocs at run time. */ 482 if (irel->r_type != R_RELLONG) 483 { 484 *errmsg = _("unsupported reloc type"); 485 bfd_set_error (bfd_error_bad_value); 486 return FALSE; 487 } 488 489 if (irel->r_symndx == -1) 490 targetsec = bfd_abs_section_ptr; 491 else 492 { 493 struct coff_link_hash_entry *h; 494 495 h = obj_coff_sym_hashes (abfd)[irel->r_symndx]; 496 if (h == NULL) 497 { 498 struct internal_syment isym; 499 500 bfd_coff_swap_sym_in (abfd, extsyms + symesz * irel->r_symndx, 501 &isym); 502 targetsec = coff_section_from_bfd_index (abfd, isym.n_scnum); 503 } 504 else if (h->root.type == bfd_link_hash_defined 505 || h->root.type == bfd_link_hash_defweak) 506 targetsec = h->root.u.def.section; 507 else 508 targetsec = NULL; 509 } 510 511 bfd_put_32 (abfd, 512 (irel->r_vaddr - datasec->vma + datasec->output_offset), p); 513 memset (p + 4, 0, 8); 514 if (targetsec != NULL) 515 strncpy ((char *) p + 4, targetsec->output_section->name, 8); 516 } 517 518 return TRUE; 519 } 520 #endif /* neither ONLY_DECLARE_RELOCS not STATIC_RELOCS */ 521 522 #define coff_bfd_is_local_label_name m68k_coff_is_local_label_name 524 525 #define coff_relocate_section _bfd_coff_generic_relocate_section 526 527 #ifndef bfd_pe_print_pdata 528 #define bfd_pe_print_pdata NULL 529 #endif 530 531 #include "coffcode.h" 532 533 #ifndef TARGET_SYM 534 #define TARGET_SYM m68k_coff_vec 535 #endif 536 537 #ifndef TARGET_NAME 538 #define TARGET_NAME "coff-m68k" 539 #endif 540 541 #ifdef NAMES_HAVE_UNDERSCORE 542 CREATE_BIG_COFF_TARGET_VEC (TARGET_SYM, TARGET_NAME, D_PAGED, 0, '_', NULL, COFF_SWAP_TABLE) 543 #else 544 CREATE_BIG_COFF_TARGET_VEC (TARGET_SYM, TARGET_NAME, D_PAGED, 0, 0, NULL, COFF_SWAP_TABLE) 545 #endif 546
