1 /* Adapteva epiphany specific support for 32-bit ELF 2 Copyright (C) 2000-2017 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 (bfd_link_relocatable (link_info) 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 /* xgettext:c-format */ 376 _bfd_error_handler (_("%B: invalid Epiphany reloc number: %d"), abfd, r_type); 377 r_type = 0; 378 } 379 cache_ptr->howto = & epiphany_elf_howto_table [r_type]; 380 } 381 382 /* Perform a single relocation. 383 By default we use the standard BFD routines. */ 384 385 static bfd_reloc_status_type 386 epiphany_final_link_relocate (reloc_howto_type * howto, 387 bfd * input_bfd, 388 asection * input_section, 389 bfd_byte * contents, 390 Elf_Internal_Rela * rel, 391 bfd_vma relocation) 392 { 393 switch (howto->type) 394 { 395 /* Handle 16 bit immediates. */ 396 case R_EPIPHANY_HIGH: 397 relocation += rel->r_addend; 398 relocation >>= 16; 399 goto common; 400 401 case R_EPIPHANY_LOW: 402 relocation += rel->r_addend; 403 common: 404 relocation = ((relocation & 0xff00L) << 12) 405 | ((relocation & 0x00ffL) << 5); 406 /* Sanity check the address. */ 407 if (rel->r_offset > bfd_get_section_limit (input_bfd, input_section)) 408 return bfd_reloc_outofrange; 409 410 return _bfd_relocate_contents (howto, input_bfd, relocation, 411 contents + rel->r_offset); 412 413 case R_EPIPHANY_SIMM11: 414 relocation += rel->r_addend; 415 /* Check signed overflow. */ 416 if ((int)relocation > 1023 || (int)relocation < -1024) 417 return bfd_reloc_outofrange; 418 goto disp11; 419 420 case R_EPIPHANY_IMM11: 421 relocation += rel->r_addend; 422 if ((unsigned int) relocation > 0x7ff) 423 return bfd_reloc_outofrange; 424 /* Fall through. */ 425 disp11: 426 relocation = (((relocation & 7) << 5) 427 | ((relocation & 0x7f8 ) << 13)); 428 return _bfd_relocate_contents (howto, input_bfd, relocation, 429 contents + rel->r_offset); 430 431 /* Pass others through. */ 432 default: 433 break; 434 } 435 436 /* Only install relocation if above tests did not disqualify it. */ 437 return _bfd_final_link_relocate (howto, input_bfd, input_section, 438 contents, rel->r_offset, 439 relocation, rel->r_addend); 440 } 441 442 /* Relocate an EPIPHANY ELF section. 443 444 The RELOCATE_SECTION function is called by the new ELF backend linker 445 to handle the relocations for a section. 446 447 The relocs are always passed as Rela structures; if the section 448 actually uses Rel structures, the r_addend field will always be 449 zero. 450 451 This function is responsible for adjusting the section contents as 452 necessary, and (if using Rela relocs and generating a relocatable 453 output file) adjusting the reloc addend as necessary. 454 455 This function does not have to worry about setting the reloc 456 address or the reloc symbol index. 457 458 LOCAL_SYMS is a pointer to the swapped in local symbols. 459 460 LOCAL_SECTIONS is an array giving the section in the input file 461 corresponding to the st_shndx field of each local symbol. 462 463 The global hash table entry for the global symbols can be found 464 via elf_sym_hashes (input_bfd). 465 466 When generating relocatable output, this function must handle 467 STB_LOCAL/STT_SECTION symbols specially. The output symbol is 468 going to be the section symbol corresponding to the output 469 section, which means that the addend must be adjusted 470 accordingly. */ 471 472 static bfd_boolean 473 epiphany_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED, 474 struct bfd_link_info *info, 475 bfd *input_bfd, 476 asection *input_section, 477 bfd_byte *contents, 478 Elf_Internal_Rela *relocs, 479 Elf_Internal_Sym *local_syms, 480 asection **local_sections) 481 { 482 Elf_Internal_Shdr *symtab_hdr; 483 struct elf_link_hash_entry **sym_hashes; 484 Elf_Internal_Rela *rel; 485 Elf_Internal_Rela *relend; 486 487 symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr; 488 sym_hashes = elf_sym_hashes (input_bfd); 489 relend = relocs + input_section->reloc_count; 490 491 for (rel = relocs; rel < relend; rel ++) 492 { 493 reloc_howto_type * howto; 494 unsigned long r_symndx; 495 Elf_Internal_Sym * sym; 496 asection * sec; 497 struct elf_link_hash_entry * h; 498 bfd_vma relocation; 499 bfd_reloc_status_type r; 500 const char * name = NULL; 501 int r_type ATTRIBUTE_UNUSED; 502 503 r_type = ELF32_R_TYPE (rel->r_info); 504 r_symndx = ELF32_R_SYM (rel->r_info); 505 howto = epiphany_elf_howto_table + ELF32_R_TYPE (rel->r_info); 506 h = NULL; 507 sym = NULL; 508 sec = NULL; 509 510 if (r_symndx < symtab_hdr->sh_info) 511 { 512 sym = local_syms + r_symndx; 513 sec = local_sections [r_symndx]; 514 relocation = BASEADDR (sec) + sym->st_value; 515 516 name = bfd_elf_string_from_elf_section 517 (input_bfd, symtab_hdr->sh_link, sym->st_name); 518 name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name; 519 } 520 else 521 { 522 bfd_boolean warned ATTRIBUTE_UNUSED; 523 bfd_boolean unresolved_reloc ATTRIBUTE_UNUSED; 524 bfd_boolean ignored ATTRIBUTE_UNUSED; 525 526 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, 527 r_symndx, symtab_hdr, sym_hashes, 528 h, sec, relocation, 529 unresolved_reloc, warned, ignored); 530 531 name = h->root.root.string; 532 } 533 534 if (sec != NULL && discarded_section (sec)) 535 RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section, 536 rel, 1, relend, howto, 0, contents); 537 538 if (bfd_link_relocatable (info)) 539 continue; 540 541 /* Finally, the sole EPIPHANY-specific part. */ 542 r = epiphany_final_link_relocate (howto, input_bfd, input_section, 543 contents, rel, relocation); 544 545 if (r != bfd_reloc_ok) 546 { 547 const char * msg = NULL; 548 549 switch (r) 550 { 551 case bfd_reloc_overflow: 552 (*info->callbacks->reloc_overflow) 553 (info, (h ? &h->root : NULL), name, howto->name, 554 (bfd_vma) 0, input_bfd, input_section, rel->r_offset); 555 break; 556 557 case bfd_reloc_undefined: 558 (*info->callbacks->undefined_symbol) 559 (info, name, input_bfd, input_section, rel->r_offset, TRUE); 560 break; 561 562 case bfd_reloc_outofrange: 563 msg = _("internal error: out of range error"); 564 break; 565 566 /* This is how epiphany_final_link_relocate tells us of a 567 non-kosher reference between insn & data address spaces. */ 568 case bfd_reloc_notsupported: 569 if (sym != NULL) /* Only if it's not an unresolved symbol. */ 570 msg = _("unsupported relocation between data/insn address spaces"); 571 break; 572 573 case bfd_reloc_dangerous: 574 msg = _("internal error: dangerous relocation"); 575 break; 576 577 default: 578 msg = _("internal error: unknown error"); 579 break; 580 } 581 582 if (msg) 583 (*info->callbacks->warning) (info, msg, name, input_bfd, 584 input_section, rel->r_offset); 585 } 586 } 587 588 return TRUE; 589 } 590 591 /* We only have a little-endian target. */ 592 #define TARGET_LITTLE_SYM epiphany_elf32_vec 593 #define TARGET_LITTLE_NAME "elf32-epiphany" 594 595 #define ELF_ARCH bfd_arch_epiphany 596 #define ELF_MACHINE_CODE EM_ADAPTEVA_EPIPHANY 597 598 #define ELF_MAXPAGESIZE 0x8000 /* No pages on the EPIPHANY. */ 599 600 #define elf_info_to_howto_rel NULL 601 #define elf_info_to_howto epiphany_info_to_howto_rela 602 603 #define elf_backend_can_gc_sections 1 604 #define elf_backend_rela_normal 1 605 #define elf_backend_relocate_section epiphany_elf_relocate_section 606 607 #define elf_symbol_leading_char '_' 608 #define bfd_elf32_bfd_reloc_type_lookup epiphany_reloc_type_lookup 609 #define bfd_elf32_bfd_reloc_name_lookup epiphany_reloc_name_lookup 610 #define bfd_elf32_bfd_relax_section epiphany_elf_relax_section 611 612 #include "elf32-target.h" 613