1/* BFD back-end for binary objects. 2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 3 2004, 2005, 2006 Free Software Foundation, Inc. 4 Written by Ian Lance Taylor, Cygnus Support, <ian@cygnus.com> 5 6 This file is part of BFD, the Binary File Descriptor library. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ 21 22/* This is a BFD backend which may be used to write binary objects. 23 It may only be used for output, not input. The intention is that 24 this may be used as an output format for objcopy in order to 25 generate raw binary data. 26 27 This is very simple. The only complication is that the real data 28 will start at some address X, and in some cases we will not want to 29 include X zeroes just to get to that point. Since the start 30 address is not meaningful for this object file format, we use it 31 instead to indicate the number of zeroes to skip at the start of 32 the file. objcopy cooperates by specially setting the start 33 address to zero by default. */ 34 35#include "bfd.h" 36#include "sysdep.h" 37#include "safe-ctype.h" 38#include "libbfd.h" 39 40/* Any bfd we create by reading a binary file has three symbols: 41 a start symbol, an end symbol, and an absolute length symbol. */ 42#define BIN_SYMS 3 43 44/* Set by external programs - specifies the BFD architecture and 45 machine number to be uses when creating binary BFDs. */ 46enum bfd_architecture bfd_external_binary_architecture = bfd_arch_unknown; 47unsigned long bfd_external_machine = 0; 48 49/* Create a binary object. Invoked via bfd_set_format. */ 50 51static bfd_boolean 52binary_mkobject (bfd *abfd ATTRIBUTE_UNUSED) 53{ 54 return TRUE; 55} 56 57/* Any file may be considered to be a binary file, provided the target 58 was not defaulted. That is, it must be explicitly specified as 59 being binary. */ 60 61static const bfd_target * 62binary_object_p (bfd *abfd) 63{ 64 struct stat statbuf; 65 asection *sec; 66 flagword flags; 67 68 if (abfd->target_defaulted) 69 { 70 bfd_set_error (bfd_error_wrong_format); 71 return NULL; 72 } 73 74 abfd->symcount = BIN_SYMS; 75 76 /* Find the file size. */ 77 if (bfd_stat (abfd, &statbuf) < 0) 78 { 79 bfd_set_error (bfd_error_system_call); 80 return NULL; 81 } 82 83 /* One data section. */ 84 flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS; 85 sec = bfd_make_section_with_flags (abfd, ".data", flags); 86 if (sec == NULL) 87 return NULL; 88 sec->vma = 0; 89 sec->size = statbuf.st_size; 90 sec->filepos = 0; 91 92 abfd->tdata.any = (void *) sec; 93 94 if (bfd_get_arch_info (abfd) != NULL) 95 { 96 if ((bfd_get_arch_info (abfd)->arch == bfd_arch_unknown) 97 && (bfd_external_binary_architecture != bfd_arch_unknown)) 98 bfd_set_arch_info (abfd, bfd_lookup_arch 99 (bfd_external_binary_architecture, bfd_external_machine)); 100 } 101 102 return abfd->xvec; 103} 104 105#define binary_close_and_cleanup _bfd_generic_close_and_cleanup 106#define binary_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 107#define binary_new_section_hook _bfd_generic_new_section_hook 108 109/* Get contents of the only section. */ 110 111static bfd_boolean 112binary_get_section_contents (bfd *abfd, 113 asection *section ATTRIBUTE_UNUSED, 114 void * location, 115 file_ptr offset, 116 bfd_size_type count) 117{ 118 if (bfd_seek (abfd, offset, SEEK_SET) != 0 119 || bfd_bread (location, count, abfd) != count) 120 return FALSE; 121 return TRUE; 122} 123 124/* Return the amount of memory needed to read the symbol table. */ 125 126static long 127binary_get_symtab_upper_bound (bfd *abfd ATTRIBUTE_UNUSED) 128{ 129 return (BIN_SYMS + 1) * sizeof (asymbol *); 130} 131 132/* Create a symbol name based on the bfd's filename. */ 133 134static char * 135mangle_name (bfd *abfd, char *suffix) 136{ 137 bfd_size_type size; 138 char *buf; 139 char *p; 140 141 size = (strlen (bfd_get_filename (abfd)) 142 + strlen (suffix) 143 + sizeof "_binary__"); 144 145 buf = bfd_alloc (abfd, size); 146 if (buf == NULL) 147 return ""; 148 149 sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix); 150 151 /* Change any non-alphanumeric characters to underscores. */ 152 for (p = buf; *p; p++) 153 if (! ISALNUM (*p)) 154 *p = '_'; 155 156 return buf; 157} 158 159/* Return the symbol table. */ 160 161static long 162binary_canonicalize_symtab (bfd *abfd, asymbol **alocation) 163{ 164 asection *sec = (asection *) abfd->tdata.any; 165 asymbol *syms; 166 unsigned int i; 167 bfd_size_type amt = BIN_SYMS * sizeof (asymbol); 168 169 syms = bfd_alloc (abfd, amt); 170 if (syms == NULL) 171 return 0; 172 173 /* Start symbol. */ 174 syms[0].the_bfd = abfd; 175 syms[0].name = mangle_name (abfd, "start"); 176 syms[0].value = 0; 177 syms[0].flags = BSF_GLOBAL; 178 syms[0].section = sec; 179 syms[0].udata.p = NULL; 180 181 /* End symbol. */ 182 syms[1].the_bfd = abfd; 183 syms[1].name = mangle_name (abfd, "end"); 184 syms[1].value = sec->size; 185 syms[1].flags = BSF_GLOBAL; 186 syms[1].section = sec; 187 syms[1].udata.p = NULL; 188 189 /* Size symbol. */ 190 syms[2].the_bfd = abfd; 191 syms[2].name = mangle_name (abfd, "size"); 192 syms[2].value = sec->size; 193 syms[2].flags = BSF_GLOBAL; 194 syms[2].section = bfd_abs_section_ptr; 195 syms[2].udata.p = NULL; 196 197 for (i = 0; i < BIN_SYMS; i++) 198 *alocation++ = syms++; 199 *alocation = NULL; 200 201 return BIN_SYMS; 202} 203 204#define binary_make_empty_symbol _bfd_generic_make_empty_symbol 205#define binary_print_symbol _bfd_nosymbols_print_symbol 206 207/* Get information about a symbol. */ 208 209static void 210binary_get_symbol_info (bfd *ignore_abfd ATTRIBUTE_UNUSED, 211 asymbol *symbol, 212 symbol_info *ret) 213{ 214 bfd_symbol_info (symbol, ret); 215} 216 217#define binary_bfd_is_local_label_name bfd_generic_is_local_label_name 218#define binary_get_lineno _bfd_nosymbols_get_lineno 219#define binary_find_nearest_line _bfd_nosymbols_find_nearest_line 220#define binary_find_inliner_info _bfd_nosymbols_find_inliner_info 221#define binary_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 222#define binary_read_minisymbols _bfd_generic_read_minisymbols 223#define binary_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol 224#define binary_bfd_reloc_type_lookup _bfd_norelocs_bfd_reloc_type_lookup 225#define binary_get_reloc_upper_bound ((long (*) (bfd *, asection *)) bfd_0l) 226#define binary_canonicalize_reloc ((long (*) (bfd *, asection *, arelent **, asymbol **)) bfd_0l) 227#define binary_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false) 228 229/* Set the architecture of a binary file. */ 230#define binary_set_arch_mach _bfd_generic_set_arch_mach 231 232/* Write section contents of a binary file. */ 233 234static bfd_boolean 235binary_set_section_contents (bfd *abfd, 236 asection *sec, 237 const void * data, 238 file_ptr offset, 239 bfd_size_type size) 240{ 241 if (size == 0) 242 return TRUE; 243 244 if (! abfd->output_has_begun) 245 { 246 bfd_boolean found_low; 247 bfd_vma low; 248 asection *s; 249 250 /* The lowest section LMA sets the virtual address of the start 251 of the file. We use this to set the file position of all the 252 sections. */ 253 found_low = FALSE; 254 low = 0; 255 for (s = abfd->sections; s != NULL; s = s->next) 256 if (((s->flags 257 & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD)) 258 == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC)) 259 && (s->size > 0) 260 && (! found_low || s->lma < low)) 261 { 262 low = s->lma; 263 found_low = TRUE; 264 } 265 266 for (s = abfd->sections; s != NULL; s = s->next) 267 { 268 s->filepos = s->lma - low; 269 270 /* Skip following warning check for sections that will not 271 occupy file space. */ 272 if ((s->flags 273 & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_NEVER_LOAD)) 274 != (SEC_HAS_CONTENTS | SEC_ALLOC) 275 || (s->size == 0)) 276 continue; 277 278 /* If attempting to generate a binary file from a bfd with 279 LMA's all over the place, huge (sparse?) binary files may 280 result. This condition attempts to detect this situation 281 and print a warning. Better heuristics would be nice to 282 have. */ 283 284 if (s->filepos < 0) 285 (*_bfd_error_handler) 286 (_("Warning: Writing section `%s' to huge (ie negative) file offset 0x%lx."), 287 bfd_get_section_name (abfd, s), 288 (unsigned long) s->filepos); 289 } 290 291 abfd->output_has_begun = TRUE; 292 } 293 294 /* We don't want to output anything for a section that is neither 295 loaded nor allocated. The contents of such a section are not 296 meaningful in the binary format. */ 297 if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0) 298 return TRUE; 299 if ((sec->flags & SEC_NEVER_LOAD) != 0) 300 return TRUE; 301 302 return _bfd_generic_set_section_contents (abfd, sec, data, offset, size); 303} 304 305/* No space is required for header information. */ 306 307static int 308binary_sizeof_headers (bfd *abfd ATTRIBUTE_UNUSED, 309 struct bfd_link_info *info ATTRIBUTE_UNUSED) 310{ 311 return 0; 312} 313 314#define binary_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents 315#define binary_bfd_relax_section bfd_generic_relax_section 316#define binary_bfd_gc_sections bfd_generic_gc_sections 317#define binary_bfd_merge_sections bfd_generic_merge_sections 318#define binary_bfd_is_group_section bfd_generic_is_group_section 319#define binary_bfd_discard_group bfd_generic_discard_group 320#define binary_section_already_linked _bfd_generic_section_already_linked 321#define binary_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 322#define binary_bfd_link_hash_table_free _bfd_generic_link_hash_table_free 323#define binary_bfd_link_just_syms _bfd_generic_link_just_syms 324#define binary_bfd_link_add_symbols _bfd_generic_link_add_symbols 325#define binary_bfd_final_link _bfd_generic_final_link 326#define binary_bfd_link_split_section _bfd_generic_link_split_section 327#define binary_get_section_contents_in_window _bfd_generic_get_section_contents_in_window 328 329const bfd_target binary_vec = 330{ 331 "binary", /* name */ 332 bfd_target_unknown_flavour, /* flavour */ 333 BFD_ENDIAN_UNKNOWN, /* byteorder */ 334 BFD_ENDIAN_UNKNOWN, /* header_byteorder */ 335 EXEC_P, /* object_flags */ 336 (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_DATA 337 | SEC_ROM | SEC_HAS_CONTENTS), /* section_flags */ 338 0, /* symbol_leading_char */ 339 ' ', /* ar_pad_char */ 340 16, /* ar_max_namelen */ 341 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 342 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 343 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */ 344 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 345 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 346 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */ 347 { /* bfd_check_format */ 348 _bfd_dummy_target, 349 binary_object_p, 350 _bfd_dummy_target, 351 _bfd_dummy_target, 352 }, 353 { /* bfd_set_format */ 354 bfd_false, 355 binary_mkobject, 356 bfd_false, 357 bfd_false, 358 }, 359 { /* bfd_write_contents */ 360 bfd_false, 361 bfd_true, 362 bfd_false, 363 bfd_false, 364 }, 365 366 BFD_JUMP_TABLE_GENERIC (binary), 367 BFD_JUMP_TABLE_COPY (_bfd_generic), 368 BFD_JUMP_TABLE_CORE (_bfd_nocore), 369 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 370 BFD_JUMP_TABLE_SYMBOLS (binary), 371 BFD_JUMP_TABLE_RELOCS (binary), 372 BFD_JUMP_TABLE_WRITE (binary), 373 BFD_JUMP_TABLE_LINK (binary), 374 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 375 376 NULL, 377 378 NULL 379}; 380