1 /* Adapteva epiphany specific support for 32-bit ELF 2 Copyright (C) 2000-2022 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 bool 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 */ \ 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, 0,0, false, 0, complain_overflow_dont, "R_EPIPHANY_NONE", 0, 0), 67 68 /* 8 bit absolute (not likely) */ 69 AHOW (R_EPIPHANY_8, 0, 1, 8, false, 0, complain_overflow_bitfield, "R_EPIPHANY_8", 0x000000ff, 0x000000ff), 70 /* 16 bit absolute */ 71 AHOW (R_EPIPHANY_16, 0, 2,16, false, 0, complain_overflow_bitfield, "R_EPIPHANY_16", 0x0000ffff, 0x00ff1fe0), 72 /* A 32 bit absolute relocation. */ 73 AHOW (R_EPIPHANY_32, 0, 4,32, false, 0, complain_overflow_dont, "R_EPIPHANY_32", 0xffffffff, 0xffffffff), 74 75 /* 8 bit relative relocation */ 76 HOWTO ( R_EPIPHANY_8_PCREL, 0, 1, 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, 2, 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, 4, 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, 1, 8, true, 8, complain_overflow_signed, "R_EPIPHANY_SIMM8", 0x000000ff, 0x0000ff00), 84 /* 24 bit pc-relative relocation */ 85 AHOW (R_EPIPHANY_SIMM24, 1, 4,24, true, 8, complain_overflow_signed, "R_EPIPHANY_SIMM24", 0x00ffffff, 0xffffff00), 86 87 /* %HIGH(EA) */ 88 AHOW (R_EPIPHANY_HIGH, 0, 4,16, false, 0, complain_overflow_dont, "R_EPIPHANY_HIGH", 0x0ff01fe0, 0x0ff01fe0), 89 90 /* %LOW(EA) */ 91 AHOW (R_EPIPHANY_LOW, 0, 4,16, false, 0, complain_overflow_dont, "R_EPIPHANY_LOW", 0x0ff01fe0, 0x0ff01fe0), 92 93 /* simm11 */ 94 AHOW (R_EPIPHANY_SIMM11, 0, 4,11, false, 0, complain_overflow_bitfield, "R_EPIPHANY_SIMM11", 0x00ff0380, 0x00ff0380), 95 /* imm12 - sign-magnitude */ 96 AHOW (R_EPIPHANY_IMM11, 0, 4,11, false, 0, complain_overflow_bitfield, "R_EPIPHANY_IMM12", 0x00ff0380, 0x00ff0380), 97 /* imm8 */ 98 AHOW (R_EPIPHANY_IMM8, 0, 2, 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 bool 179 epiphany_elf_relax_section (bfd *abfd, asection *sec, 180 struct bfd_link_info *link_info, 181 bool *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 bool new_pass = false; 193 static bool 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 (elf_section_data (sec)->relocs != internal_relocs) 345 free (internal_relocs); 346 347 return true; 348 349 error_return: 350 if (symtab_hdr->contents != (unsigned char *) isymbuf) 351 free (isymbuf); 352 if (elf_section_data (sec)->this_hdr.contents != contents) 353 free (contents); 354 if (elf_section_data (sec)->relocs != internal_relocs) 355 free (internal_relocs); 356 return false; 357 } 358 359 /* Set the howto pointer for a EPIPHANY ELF reloc. */ 360 361 static bool 362 epiphany_info_to_howto_rela (bfd * abfd, 363 arelent * cache_ptr, 364 Elf_Internal_Rela * dst) 365 { 366 unsigned int r_type; 367 368 r_type = ELF32_R_TYPE (dst->r_info); 369 if (r_type >= (unsigned int) R_EPIPHANY_max) 370 { 371 /* xgettext:c-format */ 372 _bfd_error_handler (_("%pB: unsupported relocation type %#x"), 373 abfd, r_type); 374 bfd_set_error (bfd_error_bad_value); 375 return false; 376 } 377 cache_ptr->howto = & epiphany_elf_howto_table [r_type]; 378 return true; 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 /* Fall through. */ 424 disp11: 425 relocation = (((relocation & 7) << 5) 426 | ((relocation & 0x7f8 ) << 13)); 427 return _bfd_relocate_contents (howto, input_bfd, relocation, 428 contents + rel->r_offset); 429 430 /* Pass others through. */ 431 default: 432 break; 433 } 434 435 /* Only install relocation if above tests did not disqualify it. */ 436 return _bfd_final_link_relocate (howto, input_bfd, input_section, 437 contents, rel->r_offset, 438 relocation, rel->r_addend); 439 } 440 441 /* Relocate an EPIPHANY ELF section. 442 443 The RELOCATE_SECTION function is called by the new ELF backend linker 444 to handle the relocations for a section. 445 446 The relocs are always passed as Rela structures; if the section 447 actually uses Rel structures, the r_addend field will always be 448 zero. 449 450 This function is responsible for adjusting the section contents as 451 necessary, and (if using Rela relocs and generating a relocatable 452 output file) adjusting the reloc addend as necessary. 453 454 This function does not have to worry about setting the reloc 455 address or the reloc symbol index. 456 457 LOCAL_SYMS is a pointer to the swapped in local symbols. 458 459 LOCAL_SECTIONS is an array giving the section in the input file 460 corresponding to the st_shndx field of each local symbol. 461 462 The global hash table entry for the global symbols can be found 463 via elf_sym_hashes (input_bfd). 464 465 When generating relocatable output, this function must handle 466 STB_LOCAL/STT_SECTION symbols specially. The output symbol is 467 going to be the section symbol corresponding to the output 468 section, which means that the addend must be adjusted 469 accordingly. */ 470 471 static int 472 epiphany_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED, 473 struct bfd_link_info *info, 474 bfd *input_bfd, 475 asection *input_section, 476 bfd_byte *contents, 477 Elf_Internal_Rela *relocs, 478 Elf_Internal_Sym *local_syms, 479 asection **local_sections) 480 { 481 Elf_Internal_Shdr *symtab_hdr; 482 struct elf_link_hash_entry **sym_hashes; 483 Elf_Internal_Rela *rel; 484 Elf_Internal_Rela *relend; 485 486 symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr; 487 sym_hashes = elf_sym_hashes (input_bfd); 488 relend = relocs + input_section->reloc_count; 489 490 for (rel = relocs; rel < relend; rel ++) 491 { 492 reloc_howto_type * howto; 493 unsigned long r_symndx; 494 Elf_Internal_Sym * sym; 495 asection * sec; 496 struct elf_link_hash_entry * h; 497 bfd_vma relocation; 498 bfd_reloc_status_type r; 499 const char * name = NULL; 500 int r_type ATTRIBUTE_UNUSED; 501 502 r_type = ELF32_R_TYPE (rel->r_info); 503 r_symndx = ELF32_R_SYM (rel->r_info); 504 howto = epiphany_elf_howto_table + ELF32_R_TYPE (rel->r_info); 505 h = NULL; 506 sym = NULL; 507 sec = NULL; 508 509 if (r_symndx < symtab_hdr->sh_info) 510 { 511 sym = local_syms + r_symndx; 512 sec = local_sections [r_symndx]; 513 relocation = BASEADDR (sec) + sym->st_value; 514 515 name = bfd_elf_string_from_elf_section 516 (input_bfd, symtab_hdr->sh_link, sym->st_name); 517 name = name == NULL ? bfd_section_name (sec) : name; 518 } 519 else 520 { 521 bool warned ATTRIBUTE_UNUSED; 522 bool unresolved_reloc ATTRIBUTE_UNUSED; 523 bool ignored ATTRIBUTE_UNUSED; 524 525 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, 526 r_symndx, symtab_hdr, sym_hashes, 527 h, sec, relocation, 528 unresolved_reloc, warned, ignored); 529 530 name = h->root.root.string; 531 } 532 533 if (sec != NULL && discarded_section (sec)) 534 RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section, 535 rel, 1, relend, howto, 0, contents); 536 537 if (bfd_link_relocatable (info)) 538 continue; 539 540 /* Finally, the sole EPIPHANY-specific part. */ 541 r = epiphany_final_link_relocate (howto, input_bfd, input_section, 542 contents, rel, relocation); 543 544 if (r != bfd_reloc_ok) 545 { 546 const char * msg = NULL; 547 548 switch (r) 549 { 550 case bfd_reloc_overflow: 551 (*info->callbacks->reloc_overflow) 552 (info, (h ? &h->root : NULL), name, howto->name, 553 (bfd_vma) 0, input_bfd, input_section, rel->r_offset); 554 break; 555 556 case bfd_reloc_undefined: 557 (*info->callbacks->undefined_symbol) 558 (info, name, input_bfd, input_section, rel->r_offset, true); 559 break; 560 561 case bfd_reloc_outofrange: 562 msg = _("internal error: out of range error"); 563 break; 564 565 /* This is how epiphany_final_link_relocate tells us of a 566 non-kosher reference between insn & data address spaces. */ 567 case bfd_reloc_notsupported: 568 if (sym != NULL) /* Only if it's not an unresolved symbol. */ 569 msg = _("unsupported relocation between data/insn address spaces"); 570 break; 571 572 case bfd_reloc_dangerous: 573 msg = _("internal error: dangerous relocation"); 574 break; 575 576 default: 577 msg = _("internal error: unknown error"); 578 break; 579 } 580 581 if (msg) 582 (*info->callbacks->warning) (info, msg, name, input_bfd, 583 input_section, rel->r_offset); 584 } 585 } 586 587 return true; 588 } 589 590 /* We only have a little-endian target. */ 591 #define TARGET_LITTLE_SYM epiphany_elf32_vec 592 #define TARGET_LITTLE_NAME "elf32-epiphany" 593 594 #define ELF_ARCH bfd_arch_epiphany 595 #define ELF_MACHINE_CODE EM_ADAPTEVA_EPIPHANY 596 597 #define ELF_MAXPAGESIZE 0x8000 /* No pages on the EPIPHANY. */ 598 599 #define elf_info_to_howto_rel NULL 600 #define elf_info_to_howto epiphany_info_to_howto_rela 601 602 #define elf_backend_can_gc_sections 1 603 #define elf_backend_rela_normal 1 604 #define elf_backend_relocate_section epiphany_elf_relocate_section 605 606 #define elf_symbol_leading_char '_' 607 #define bfd_elf32_bfd_reloc_type_lookup epiphany_reloc_type_lookup 608 #define bfd_elf32_bfd_reloc_name_lookup epiphany_reloc_name_lookup 609 #define bfd_elf32_bfd_relax_section epiphany_elf_relax_section 610 611 #include "elf32-target.h" 612