1 /* Adapteva epiphany specific support for 32-bit ELF 2 Copyright (C) 2000-2015 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, 3,0, 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 if (r_type >= (unsigned int) R_EPIPHANY_max) 374 { 375 _bfd_error_handler (_("%B: invalid Epiphany reloc number: %d"), abfd, r_type); 376 r_type = 0; 377 } 378 cache_ptr->howto = & epiphany_elf_howto_table [r_type]; 379 } 380 381 /* Perform a single relocation. 382 By default we use the standard BFD routines. */ 383 384 static bfd_reloc_status_type 385 epiphany_final_link_relocate (reloc_howto_type * howto, 386 bfd * input_bfd, 387 asection * input_section, 388 bfd_byte * contents, 389 Elf_Internal_Rela * rel, 390 bfd_vma relocation) 391 { 392 switch (howto->type) 393 { 394 /* Handle 16 bit immediates. */ 395 case R_EPIPHANY_HIGH: 396 relocation += rel->r_addend; 397 relocation >>= 16; 398 goto common; 399 400 case R_EPIPHANY_LOW: 401 relocation += rel->r_addend; 402 common: 403 relocation = ((relocation & 0xff00L) << 12) 404 | ((relocation & 0x00ffL) << 5); 405 /* Sanity check the address. */ 406 if (rel->r_offset > bfd_get_section_limit (input_bfd, input_section)) 407 return bfd_reloc_outofrange; 408 409 return _bfd_relocate_contents (howto, input_bfd, relocation, 410 contents + rel->r_offset); 411 412 case R_EPIPHANY_SIMM11: 413 relocation += rel->r_addend; 414 /* Check signed overflow. */ 415 if ((int)relocation > 1023 || (int)relocation < -1024) 416 return bfd_reloc_outofrange; 417 goto disp11; 418 419 case R_EPIPHANY_IMM11: 420 relocation += rel->r_addend; 421 if ((unsigned int) relocation > 0x7ff) 422 return bfd_reloc_outofrange; 423 disp11: 424 relocation = ((relocation & 7) << 5) 425 || ((relocation & 0x7f8 ) << 13); 426 return _bfd_relocate_contents (howto, input_bfd, relocation, 427 contents + rel->r_offset); 428 429 /* Pass others through. */ 430 default: 431 break; 432 } 433 434 /* Only install relocation if above tests did not disqualify it. */ 435 return _bfd_final_link_relocate (howto, input_bfd, input_section, 436 contents, rel->r_offset, 437 relocation, rel->r_addend); 438 } 439 440 /* Relocate an EPIPHANY ELF section. 441 442 The RELOCATE_SECTION function is called by the new ELF backend linker 443 to handle the relocations for a section. 444 445 The relocs are always passed as Rela structures; if the section 446 actually uses Rel structures, the r_addend field will always be 447 zero. 448 449 This function is responsible for adjusting the section contents as 450 necessary, and (if using Rela relocs and generating a relocatable 451 output file) adjusting the reloc addend as necessary. 452 453 This function does not have to worry about setting the reloc 454 address or the reloc symbol index. 455 456 LOCAL_SYMS is a pointer to the swapped in local symbols. 457 458 LOCAL_SECTIONS is an array giving the section in the input file 459 corresponding to the st_shndx field of each local symbol. 460 461 The global hash table entry for the global symbols can be found 462 via elf_sym_hashes (input_bfd). 463 464 When generating relocatable output, this function must handle 465 STB_LOCAL/STT_SECTION symbols specially. The output symbol is 466 going to be the section symbol corresponding to the output 467 section, which means that the addend must be adjusted 468 accordingly. */ 469 470 static bfd_boolean 471 epiphany_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED, 472 struct bfd_link_info *info, 473 bfd *input_bfd, 474 asection *input_section, 475 bfd_byte *contents, 476 Elf_Internal_Rela *relocs, 477 Elf_Internal_Sym *local_syms, 478 asection **local_sections) 479 { 480 Elf_Internal_Shdr *symtab_hdr; 481 struct elf_link_hash_entry **sym_hashes; 482 Elf_Internal_Rela *rel; 483 Elf_Internal_Rela *relend; 484 485 symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr; 486 sym_hashes = elf_sym_hashes (input_bfd); 487 relend = relocs + input_section->reloc_count; 488 489 for (rel = relocs; rel < relend; rel ++) 490 { 491 reloc_howto_type * howto; 492 unsigned long r_symndx; 493 Elf_Internal_Sym * sym; 494 asection * sec; 495 struct elf_link_hash_entry * h; 496 bfd_vma relocation; 497 bfd_reloc_status_type r; 498 const char * name = NULL; 499 int r_type ATTRIBUTE_UNUSED; 500 501 r_type = ELF32_R_TYPE (rel->r_info); 502 r_symndx = ELF32_R_SYM (rel->r_info); 503 howto = epiphany_elf_howto_table + ELF32_R_TYPE (rel->r_info); 504 h = NULL; 505 sym = NULL; 506 sec = NULL; 507 508 if (r_symndx < symtab_hdr->sh_info) 509 { 510 sym = local_syms + r_symndx; 511 sec = local_sections [r_symndx]; 512 relocation = BASEADDR (sec) + sym->st_value; 513 514 name = bfd_elf_string_from_elf_section 515 (input_bfd, symtab_hdr->sh_link, sym->st_name); 516 name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name; 517 } 518 else 519 { 520 bfd_boolean warned ATTRIBUTE_UNUSED; 521 bfd_boolean unresolved_reloc ATTRIBUTE_UNUSED; 522 bfd_boolean ignored ATTRIBUTE_UNUSED; 523 524 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, 525 r_symndx, symtab_hdr, sym_hashes, 526 h, sec, relocation, 527 unresolved_reloc, warned, ignored); 528 529 name = h->root.root.string; 530 } 531 532 if (sec != NULL && discarded_section (sec)) 533 RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section, 534 rel, 1, relend, howto, 0, contents); 535 536 if (info->relocatable) 537 continue; 538 539 /* Finally, the sole EPIPHANY-specific part. */ 540 r = epiphany_final_link_relocate (howto, input_bfd, input_section, 541 contents, rel, relocation); 542 543 if (r != bfd_reloc_ok) 544 { 545 const char * msg = NULL; 546 547 switch (r) 548 { 549 case bfd_reloc_overflow: 550 r = info->callbacks->reloc_overflow 551 (info, (h ? &h->root : NULL), name, howto->name, 552 (bfd_vma) 0, input_bfd, input_section, rel->r_offset); 553 break; 554 555 case bfd_reloc_undefined: 556 r = info->callbacks->undefined_symbol 557 (info, name, input_bfd, input_section, rel->r_offset, TRUE); 558 break; 559 560 case bfd_reloc_outofrange: 561 msg = _("internal error: out of range error"); 562 break; 563 564 /* This is how epiphany_final_link_relocate tells us of a 565 non-kosher reference between insn & data address spaces. */ 566 case bfd_reloc_notsupported: 567 if (sym != NULL) /* Only if it's not an unresolved symbol. */ 568 msg = _("unsupported relocation between data/insn address spaces"); 569 break; 570 571 case bfd_reloc_dangerous: 572 msg = _("internal error: dangerous relocation"); 573 break; 574 575 default: 576 msg = _("internal error: unknown error"); 577 break; 578 } 579 580 if (msg) 581 r = info->callbacks->warning 582 (info, msg, name, input_bfd, input_section, rel->r_offset); 583 584 if (! r) 585 return FALSE; 586 } 587 } 588 589 return TRUE; 590 } 591 592 /* We only have a little-endian target. */ 593 #define TARGET_LITTLE_SYM epiphany_elf32_vec 594 #define TARGET_LITTLE_NAME "elf32-epiphany" 595 596 #define ELF_ARCH bfd_arch_epiphany 597 #define ELF_MACHINE_CODE EM_ADAPTEVA_EPIPHANY 598 599 #define ELF_MAXPAGESIZE 0x8000 /* No pages on the EPIPHANY. */ 600 601 #define elf_info_to_howto_rel NULL 602 #define elf_info_to_howto epiphany_info_to_howto_rela 603 604 #define elf_backend_can_gc_sections 1 605 #define elf_backend_rela_normal 1 606 #define elf_backend_relocate_section epiphany_elf_relocate_section 607 608 #define elf_symbol_leading_char '_' 609 #define bfd_elf32_bfd_reloc_type_lookup epiphany_reloc_type_lookup 610 #define bfd_elf32_bfd_reloc_name_lookup epiphany_reloc_name_lookup 611 #define bfd_elf32_bfd_relax_section epiphany_elf_relax_section 612 613 #include "elf32-target.h" 614