1 /* Adapteva epiphany specific support for 32-bit ELF 2 Copyright (C) 2000-2014 Free Software Foundation, Inc. 3 Contributed by Embecosm on behalf of Adapteva, 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 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 "elf-bfd.h" 26 #include "elf/epiphany.h" 27 #include "libiberty.h" 28 29 /* Struct used to pass miscellaneous paramaters which 30 helps to avoid overly long parameter lists. */ 31 struct misc 32 { 33 Elf_Internal_Shdr * symtab_hdr; 34 Elf_Internal_Rela * irelbase; 35 bfd_byte * contents; 36 Elf_Internal_Sym * isymbuf; 37 }; 38 39 struct epiphany_opcode 40 { 41 unsigned short opcode; 42 unsigned short mask; 43 }; 44 45 static bfd_boolean epiphany_relaxed = FALSE; 46 47 /* Relocation tables. */ 48 static reloc_howto_type epiphany_elf_howto_table [] = 49 { 50 #define AHOW(t,rs,s,bs,pr,bp,co,name,sm,dm) \ 51 HOWTO(t, /* type */ \ 52 rs, /* rightshift */ \ 53 s, /* size (0 = byte, 1 = short, 2 = long) */ \ 54 bs, /* bitsize */ \ 55 pr, /* pc_relative */ \ 56 bp, /* bitpos */ \ 57 co, /* complain_on_overflow */ \ 58 bfd_elf_generic_reloc,/* special_function */ \ 59 name, /* name */ \ 60 FALSE, /* partial_inplace */ \ 61 sm, /* src_mask */ \ 62 dm, /* dst_mask */ \ 63 pr) /* pcrel_offset */ 64 65 /* This reloc does nothing. */ 66 AHOW (R_EPIPHANY_NONE, 0, 0,32, FALSE, 0, complain_overflow_dont, "R_EPIPHANY_NONE", 0, 0), 67 68 /* 8 bit absolute (not likely) */ 69 AHOW (R_EPIPHANY_8, 0, 0, 8, FALSE, 0, complain_overflow_bitfield, "R_EPIPHANY_8", 0x000000ff, 0x000000ff), 70 /* 16 bit absolute */ 71 AHOW (R_EPIPHANY_16, 0, 1,16, FALSE, 0, complain_overflow_bitfield, "R_EPIPHANY_16", 0x0000ffff, 0x00ff1fe0), 72 /* A 32 bit absolute relocation. */ 73 AHOW (R_EPIPHANY_32, 0, 2,32, FALSE, 0, complain_overflow_dont, "R_EPIPHANY_32", 0xffffffff, 0xffffffff), 74 75 /* 8 bit relative relocation */ 76 HOWTO ( R_EPIPHANY_8_PCREL, 0, 0, 8, TRUE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_EPIPHANY_8_PCREL", FALSE, 0x000000ff, 0x000000ff, FALSE), 77 /* 16 bit relative relocation */ 78 HOWTO ( R_EPIPHANY_16_PCREL, 0, 1, 16, TRUE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_EPIPHANY_8_PCREL", FALSE, 0x000000ff, 0x000000ff, FALSE), 79 /* 32 bit relative relocation */ 80 HOWTO ( R_EPIPHANY_32_PCREL, 0, 2, 32, TRUE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_EPIPHANY_8_PCREL", FALSE, 0x000000ff, 0x000000ff, FALSE), 81 82 /* 8 bit pc-relative relocation */ 83 AHOW (R_EPIPHANY_SIMM8, 1, 0, 8, TRUE, 8, complain_overflow_signed, "R_EPIPHANY_SIMM8", 0x000000ff, 0x0000ff00), 84 /* 24 bit pc-relative relocation */ 85 AHOW (R_EPIPHANY_SIMM24, 1, 2,24, TRUE, 8, complain_overflow_signed, "R_EPIPHANY_SIMM24", 0x00ffffff, 0xffffff00), 86 87 /* %HIGH(EA) */ 88 AHOW (R_EPIPHANY_HIGH, 0, 2,16, FALSE, 0, complain_overflow_dont, "R_EPIPHANY_HIGH", 0x0ff01fe0, 0x0ff01fe0), 89 90 /* %LOW(EA) */ 91 AHOW (R_EPIPHANY_LOW, 0, 2,16, FALSE, 0, complain_overflow_dont, "R_EPIPHANY_LOW", 0x0ff01fe0, 0x0ff01fe0), 92 93 /* simm11 */ 94 AHOW (R_EPIPHANY_SIMM11, 0, 2,11, FALSE, 0, complain_overflow_bitfield, "R_EPIPHANY_SIMM11", 0x00ff0380, 0x00ff0380), 95 /* imm12 - sign-magnitude */ 96 AHOW (R_EPIPHANY_IMM11, 0, 2,11, FALSE, 0, complain_overflow_bitfield, "R_EPIPHANY_IMM12", 0x00ff0380, 0x00ff0380), 97 /* imm8 */ 98 AHOW (R_EPIPHANY_IMM8, 0, 1, 8, FALSE, 8, complain_overflow_signed, "R_EPIPHANY_IMM8", 0x0000ff00, 0x0000ff00) 99 100 101 }; 102 #undef AHOW 103 104 /* Map BFD reloc types to EPIPHANY ELF reloc types. */ 105 106 static reloc_howto_type * 107 epiphany_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED, 108 bfd_reloc_code_real_type code) 109 { 110 /* Note that the epiphany_elf_howto_table is indxed by the R_ 111 constants. Thus, the order that the howto records appear in the 112 table *must* match the order of the relocation types defined in 113 include/elf/epiphany.h. */ 114 115 switch (code) 116 { 117 case BFD_RELOC_NONE: 118 return &epiphany_elf_howto_table[ (int) R_EPIPHANY_NONE]; 119 120 case BFD_RELOC_EPIPHANY_SIMM8: 121 return &epiphany_elf_howto_table[ (int) R_EPIPHANY_SIMM8]; 122 case BFD_RELOC_EPIPHANY_SIMM24: 123 return &epiphany_elf_howto_table[ (int) R_EPIPHANY_SIMM24]; 124 125 case BFD_RELOC_8_PCREL: 126 return &epiphany_elf_howto_table[ (int) R_EPIPHANY_8_PCREL]; 127 case BFD_RELOC_16_PCREL: 128 return &epiphany_elf_howto_table[ (int) R_EPIPHANY_16_PCREL]; 129 case BFD_RELOC_32_PCREL: 130 return &epiphany_elf_howto_table[ (int) R_EPIPHANY_32_PCREL]; 131 132 case BFD_RELOC_8: 133 return &epiphany_elf_howto_table[ (int) R_EPIPHANY_8]; 134 case BFD_RELOC_16: 135 return &epiphany_elf_howto_table[ (int) R_EPIPHANY_16]; 136 case BFD_RELOC_32: 137 return &epiphany_elf_howto_table[ (int) R_EPIPHANY_32]; 138 139 case BFD_RELOC_EPIPHANY_HIGH: 140 return & epiphany_elf_howto_table[ (int) R_EPIPHANY_HIGH]; 141 case BFD_RELOC_EPIPHANY_LOW: 142 return & epiphany_elf_howto_table[ (int) R_EPIPHANY_LOW]; 143 144 case BFD_RELOC_EPIPHANY_SIMM11: 145 return & epiphany_elf_howto_table[ (int) R_EPIPHANY_SIMM11]; 146 case BFD_RELOC_EPIPHANY_IMM11: 147 return & epiphany_elf_howto_table[ (int) R_EPIPHANY_IMM11]; 148 149 case BFD_RELOC_EPIPHANY_IMM8: 150 return & epiphany_elf_howto_table[ (int) R_EPIPHANY_IMM8]; 151 152 default: 153 /* Pacify gcc -Wall. */ 154 return NULL; 155 } 156 return NULL; 157 } 158 159 static reloc_howto_type * 160 epiphany_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, const char *r_name) 161 { 162 unsigned int i; 163 164 for (i = 0; i < ARRAY_SIZE (epiphany_elf_howto_table); i++) 165 if (epiphany_elf_howto_table[i].name != NULL 166 && strcasecmp (epiphany_elf_howto_table[i].name, r_name) == 0) 167 return &epiphany_elf_howto_table[i]; 168 169 return NULL; 170 } 171 172 #define PAGENO(ABSADDR) ((ABSADDR) & 0xFFFFC000) 173 #define BASEADDR(SEC) ((SEC)->output_section->vma + (SEC)->output_offset) 174 175 /* This function handles relaxing for the epiphany. 176 Dummy placeholder for future optimizations. */ 177 178 static bfd_boolean 179 epiphany_elf_relax_section (bfd *abfd, asection *sec, 180 struct bfd_link_info *link_info, 181 bfd_boolean *again) 182 { 183 Elf_Internal_Shdr *symtab_hdr; 184 Elf_Internal_Rela *internal_relocs; 185 bfd_byte *contents = NULL; 186 Elf_Internal_Sym *isymbuf = NULL; 187 static asection * first_section = NULL; 188 static unsigned long search_addr; 189 static unsigned long page_start = 0; 190 static unsigned long page_end = 0; 191 static unsigned int pass = 0; 192 static bfd_boolean new_pass = FALSE; 193 static bfd_boolean changed = FALSE; 194 struct misc misc ATTRIBUTE_UNUSED; 195 asection *stab; 196 197 /* Assume nothing changes. */ 198 *again = FALSE; 199 200 if (first_section == NULL) 201 { 202 epiphany_relaxed = TRUE; 203 first_section = sec; 204 } 205 206 if (first_section == sec) 207 { 208 pass++; 209 new_pass = TRUE; 210 } 211 212 /* We don't have to do anything for a relocatable link, 213 if this section does not have relocs, or if this is 214 not a code section. */ 215 if (link_info->relocatable 216 || (sec->flags & SEC_RELOC) == 0 217 || sec->reloc_count == 0 218 || (sec->flags & SEC_CODE) == 0) 219 return TRUE; 220 221 symtab_hdr = &elf_tdata (abfd)->symtab_hdr; 222 223 internal_relocs = _bfd_elf_link_read_relocs (abfd, sec, NULL, NULL, 224 link_info->keep_memory); 225 if (internal_relocs == NULL) 226 goto error_return; 227 228 /* Make sure the stac.rela stuff gets read in. */ 229 stab = bfd_get_section_by_name (abfd, ".stab"); 230 231 if (stab) 232 { 233 /* So stab does exits. */ 234 Elf_Internal_Rela * irelbase ATTRIBUTE_UNUSED; 235 236 irelbase = _bfd_elf_link_read_relocs (abfd, stab, NULL, NULL, 237 link_info->keep_memory); 238 } 239 240 /* Get section contents cached copy if it exists. */ 241 if (contents == NULL) 242 { 243 /* Get cached copy if it exists. */ 244 if (elf_section_data (sec)->this_hdr.contents != NULL) 245 contents = elf_section_data (sec)->this_hdr.contents; 246 else 247 { 248 /* Go get them off disk. */ 249 if (!bfd_malloc_and_get_section (abfd, sec, &contents)) 250 goto error_return; 251 } 252 } 253 254 /* Read this BFD's symbols cached copy if it exists. */ 255 if (isymbuf == NULL && symtab_hdr->sh_info != 0) 256 { 257 isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents; 258 if (isymbuf == NULL) 259 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr, 260 symtab_hdr->sh_info, 0, 261 NULL, NULL, NULL); 262 if (isymbuf == NULL) 263 goto error_return; 264 } 265 266 misc.symtab_hdr = symtab_hdr; 267 misc.isymbuf = isymbuf; 268 misc.irelbase = internal_relocs; 269 misc.contents = contents; 270 271 /* This is where all the relaxation actually get done. */ 272 if ((pass == 1) || (new_pass && !changed)) 273 { 274 /* On the first pass we simply search for the lowest page that 275 we havn't relaxed yet. Note that the pass count is reset 276 each time a page is complete in order to move on to the next page. 277 If we can't find any more pages then we are finished. */ 278 if (new_pass) 279 { 280 pass = 1; 281 new_pass = FALSE; 282 changed = TRUE; /* Pre-initialize to break out of pass 1. */ 283 search_addr = 0xFFFFFFFF; 284 } 285 286 if ((BASEADDR (sec) + sec->size < search_addr) 287 && (BASEADDR (sec) + sec->size > page_end)) 288 { 289 if (BASEADDR (sec) <= page_end) 290 search_addr = page_end + 1; 291 else 292 search_addr = BASEADDR (sec); 293 294 /* Found a page => more work to do. */ 295 *again = TRUE; 296 } 297 } 298 else 299 { 300 if (new_pass) 301 { 302 new_pass = FALSE; 303 changed = FALSE; 304 page_start = PAGENO (search_addr); 305 page_end = page_start | 0x00003FFF; 306 } 307 308 /* Only process sections in range. */ 309 if ((BASEADDR (sec) + sec->size >= page_start) 310 && (BASEADDR (sec) <= page_end)) 311 { 312 #if 0 313 if (!epiphany_elf_relax_section_page (abfd, sec, &changed, &misc, 314 page_start, page_end)) 315 #endif 316 return FALSE; 317 } 318 *again = TRUE; 319 } 320 321 /* Perform some house keeping after relaxing the section. */ 322 323 if (isymbuf != NULL 324 && symtab_hdr->contents != (unsigned char *) isymbuf) 325 { 326 if (! link_info->keep_memory) 327 free (isymbuf); 328 else 329 symtab_hdr->contents = (unsigned char *) isymbuf; 330 } 331 332 if (contents != NULL 333 && elf_section_data (sec)->this_hdr.contents != contents) 334 { 335 if (! link_info->keep_memory) 336 free (contents); 337 else 338 { 339 /* Cache the section contents for elf_link_input_bfd. */ 340 elf_section_data (sec)->this_hdr.contents = contents; 341 } 342 } 343 344 if (internal_relocs != NULL 345 && elf_section_data (sec)->relocs != internal_relocs) 346 free (internal_relocs); 347 348 return TRUE; 349 350 error_return: 351 if (isymbuf != NULL 352 && symtab_hdr->contents != (unsigned char *) isymbuf) 353 free (isymbuf); 354 if (contents != NULL 355 && elf_section_data (sec)->this_hdr.contents != contents) 356 free (contents); 357 if (internal_relocs != NULL 358 && elf_section_data (sec)->relocs != internal_relocs) 359 free (internal_relocs); 360 return FALSE; 361 } 362 363 /* Set the howto pointer for a EPIPHANY ELF reloc. */ 364 365 static void 366 epiphany_info_to_howto_rela (bfd * abfd ATTRIBUTE_UNUSED, 367 arelent * cache_ptr, 368 Elf_Internal_Rela * dst) 369 { 370 unsigned int r_type; 371 372 r_type = ELF32_R_TYPE (dst->r_info); 373 cache_ptr->howto = & epiphany_elf_howto_table [r_type]; 374 } 375 376 /* Perform a single relocation. 377 By default we use the standard BFD routines. */ 378 379 static bfd_reloc_status_type 380 epiphany_final_link_relocate (reloc_howto_type * howto, 381 bfd * input_bfd, 382 asection * input_section, 383 bfd_byte * contents, 384 Elf_Internal_Rela * rel, 385 bfd_vma relocation) 386 { 387 switch (howto->type) 388 { 389 /* Handle 16 bit immediates. */ 390 case R_EPIPHANY_HIGH: 391 relocation += rel->r_addend; 392 relocation >>= 16; 393 goto common; 394 395 case R_EPIPHANY_LOW: 396 relocation += rel->r_addend; 397 common: 398 relocation = ((relocation & 0xff00L) << 12) 399 | ((relocation & 0x00ffL) << 5); 400 /* Sanity check the address. */ 401 if (rel->r_offset > bfd_get_section_limit (input_bfd, input_section)) 402 return bfd_reloc_outofrange; 403 404 return _bfd_relocate_contents (howto, input_bfd, relocation, 405 contents + rel->r_offset); 406 407 case R_EPIPHANY_SIMM11: 408 relocation += rel->r_addend; 409 /* Check signed overflow. */ 410 if ((int)relocation > 1023 || (int)relocation < -1024) 411 return bfd_reloc_outofrange; 412 goto disp11; 413 414 case R_EPIPHANY_IMM11: 415 relocation += rel->r_addend; 416 if ((unsigned int) relocation > 0x7ff) 417 return bfd_reloc_outofrange; 418 disp11: 419 relocation = ((relocation & 7) << 5) 420 || ((relocation & 0x7f8 ) << 13); 421 return _bfd_relocate_contents (howto, input_bfd, relocation, 422 contents + rel->r_offset); 423 424 /* Pass others through. */ 425 default: 426 break; 427 } 428 429 /* Only install relocation if above tests did not disqualify it. */ 430 return _bfd_final_link_relocate (howto, input_bfd, input_section, 431 contents, rel->r_offset, 432 relocation, rel->r_addend); 433 } 434 435 /* Relocate an EPIPHANY ELF section. 436 437 The RELOCATE_SECTION function is called by the new ELF backend linker 438 to handle the relocations for a section. 439 440 The relocs are always passed as Rela structures; if the section 441 actually uses Rel structures, the r_addend field will always be 442 zero. 443 444 This function is responsible for adjusting the section contents as 445 necessary, and (if using Rela relocs and generating a relocatable 446 output file) adjusting the reloc addend as necessary. 447 448 This function does not have to worry about setting the reloc 449 address or the reloc symbol index. 450 451 LOCAL_SYMS is a pointer to the swapped in local symbols. 452 453 LOCAL_SECTIONS is an array giving the section in the input file 454 corresponding to the st_shndx field of each local symbol. 455 456 The global hash table entry for the global symbols can be found 457 via elf_sym_hashes (input_bfd). 458 459 When generating relocatable output, this function must handle 460 STB_LOCAL/STT_SECTION symbols specially. The output symbol is 461 going to be the section symbol corresponding to the output 462 section, which means that the addend must be adjusted 463 accordingly. */ 464 465 static bfd_boolean 466 epiphany_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED, 467 struct bfd_link_info *info, 468 bfd *input_bfd, 469 asection *input_section, 470 bfd_byte *contents, 471 Elf_Internal_Rela *relocs, 472 Elf_Internal_Sym *local_syms, 473 asection **local_sections) 474 { 475 Elf_Internal_Shdr *symtab_hdr; 476 struct elf_link_hash_entry **sym_hashes; 477 Elf_Internal_Rela *rel; 478 Elf_Internal_Rela *relend; 479 480 symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr; 481 sym_hashes = elf_sym_hashes (input_bfd); 482 relend = relocs + input_section->reloc_count; 483 484 for (rel = relocs; rel < relend; rel ++) 485 { 486 reloc_howto_type * howto; 487 unsigned long r_symndx; 488 Elf_Internal_Sym * sym; 489 asection * sec; 490 struct elf_link_hash_entry * h; 491 bfd_vma relocation; 492 bfd_reloc_status_type r; 493 const char * name = NULL; 494 int r_type ATTRIBUTE_UNUSED; 495 496 r_type = ELF32_R_TYPE (rel->r_info); 497 r_symndx = ELF32_R_SYM (rel->r_info); 498 howto = epiphany_elf_howto_table + ELF32_R_TYPE (rel->r_info); 499 h = NULL; 500 sym = NULL; 501 sec = NULL; 502 503 if (r_symndx < symtab_hdr->sh_info) 504 { 505 sym = local_syms + r_symndx; 506 sec = local_sections [r_symndx]; 507 relocation = BASEADDR (sec) + sym->st_value; 508 509 name = bfd_elf_string_from_elf_section 510 (input_bfd, symtab_hdr->sh_link, sym->st_name); 511 name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name; 512 } 513 else 514 { 515 bfd_boolean warned ATTRIBUTE_UNUSED; 516 bfd_boolean unresolved_reloc ATTRIBUTE_UNUSED; 517 bfd_boolean ignored ATTRIBUTE_UNUSED; 518 519 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, 520 r_symndx, symtab_hdr, sym_hashes, 521 h, sec, relocation, 522 unresolved_reloc, warned, ignored); 523 524 name = h->root.root.string; 525 } 526 527 if (sec != NULL && discarded_section (sec)) 528 RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section, 529 rel, 1, relend, howto, 0, contents); 530 531 if (info->relocatable) 532 continue; 533 534 /* Finally, the sole EPIPHANY-specific part. */ 535 r = epiphany_final_link_relocate (howto, input_bfd, input_section, 536 contents, rel, relocation); 537 538 if (r != bfd_reloc_ok) 539 { 540 const char * msg = NULL; 541 542 switch (r) 543 { 544 case bfd_reloc_overflow: 545 r = info->callbacks->reloc_overflow 546 (info, (h ? &h->root : NULL), name, howto->name, 547 (bfd_vma) 0, input_bfd, input_section, rel->r_offset); 548 break; 549 550 case bfd_reloc_undefined: 551 r = info->callbacks->undefined_symbol 552 (info, name, input_bfd, input_section, rel->r_offset, TRUE); 553 break; 554 555 case bfd_reloc_outofrange: 556 msg = _("internal error: out of range error"); 557 break; 558 559 /* This is how epiphany_final_link_relocate tells us of a 560 non-kosher reference between insn & data address spaces. */ 561 case bfd_reloc_notsupported: 562 if (sym != NULL) /* Only if it's not an unresolved symbol. */ 563 msg = _("unsupported relocation between data/insn address spaces"); 564 break; 565 566 case bfd_reloc_dangerous: 567 msg = _("internal error: dangerous relocation"); 568 break; 569 570 default: 571 msg = _("internal error: unknown error"); 572 break; 573 } 574 575 if (msg) 576 r = info->callbacks->warning 577 (info, msg, name, input_bfd, input_section, rel->r_offset); 578 579 if (! r) 580 return FALSE; 581 } 582 } 583 584 return TRUE; 585 } 586 587 /* We only have a little-endian target. */ 588 #define TARGET_LITTLE_SYM epiphany_elf32_vec 589 #define TARGET_LITTLE_NAME "elf32-epiphany" 590 591 #define ELF_ARCH bfd_arch_epiphany 592 #define ELF_MACHINE_CODE EM_ADAPTEVA_EPIPHANY 593 594 #define ELF_MAXPAGESIZE 0x8000 /* No pages on the EPIPHANY. */ 595 596 #define elf_info_to_howto_rel NULL 597 #define elf_info_to_howto epiphany_info_to_howto_rela 598 599 #define elf_backend_can_gc_sections 1 600 #define elf_backend_rela_normal 1 601 #define elf_backend_relocate_section epiphany_elf_relocate_section 602 603 #define elf_symbol_leading_char '_' 604 #define bfd_elf32_bfd_reloc_type_lookup epiphany_reloc_type_lookup 605 #define bfd_elf32_bfd_reloc_name_lookup epiphany_reloc_name_lookup 606 #define bfd_elf32_bfd_relax_section epiphany_elf_relax_section 607 608 #include "elf32-target.h" 609
