| 1 | /* BFD back-end for binary objects. |
| 2 | Copyright (C) 1994-2019 Free Software Foundation, Inc. |
| 3 | Written by Ian Lance Taylor, Cygnus Support, <ian@cygnus.com> |
| 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 | /* 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 "sysdep.h" |
| 36 | #include "bfd.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 | /* Create a binary object. Invoked via bfd_set_format. */ |
| 45 | |
| 46 | static bfd_boolean |
| 47 | binary_mkobject (bfd *abfd ATTRIBUTE_UNUSED) |
| 48 | { |
| 49 | return TRUE; |
| 50 | } |
| 51 | |
| 52 | /* Any file may be considered to be a binary file, provided the target |
| 53 | was not defaulted. That is, it must be explicitly specified as |
| 54 | being binary. */ |
| 55 | |
| 56 | static const bfd_target * |
| 57 | binary_object_p (bfd *abfd) |
| 58 | { |
| 59 | struct stat statbuf; |
| 60 | asection *sec; |
| 61 | flagword flags; |
| 62 | |
| 63 | if (abfd->target_defaulted) |
| 64 | { |
| 65 | bfd_set_error (bfd_error_wrong_format); |
| 66 | return NULL; |
| 67 | } |
| 68 | |
| 69 | abfd->symcount = BIN_SYMS; |
| 70 | |
| 71 | /* Find the file size. */ |
| 72 | if (bfd_stat (abfd, &statbuf) < 0) |
| 73 | { |
| 74 | bfd_set_error (bfd_error_system_call); |
| 75 | return NULL; |
| 76 | } |
| 77 | |
| 78 | /* One data section. */ |
| 79 | flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS; |
| 80 | sec = bfd_make_section_with_flags (abfd, ".data", flags); |
| 81 | if (sec == NULL) |
| 82 | return NULL; |
| 83 | sec->vma = 0; |
| 84 | sec->size = statbuf.st_size; |
| 85 | sec->filepos = 0; |
| 86 | |
| 87 | abfd->tdata.any = (void *) sec; |
| 88 | |
| 89 | return abfd->xvec; |
| 90 | } |
| 91 | |
| 92 | #define binary_close_and_cleanup _bfd_generic_close_and_cleanup |
| 93 | #define binary_bfd_free_cached_info _bfd_generic_bfd_free_cached_info |
| 94 | #define binary_new_section_hook _bfd_generic_new_section_hook |
| 95 | |
| 96 | /* Get contents of the only section. */ |
| 97 | |
| 98 | static bfd_boolean |
| 99 | binary_get_section_contents (bfd *abfd, |
| 100 | asection *section ATTRIBUTE_UNUSED, |
| 101 | void * location, |
| 102 | file_ptr offset, |
| 103 | bfd_size_type count) |
| 104 | { |
| 105 | if (bfd_seek (abfd, offset, SEEK_SET) != 0 |
| 106 | || bfd_bread (location, count, abfd) != count) |
| 107 | return FALSE; |
| 108 | return TRUE; |
| 109 | } |
| 110 | |
| 111 | /* Return the amount of memory needed to read the symbol table. */ |
| 112 | |
| 113 | static long |
| 114 | binary_get_symtab_upper_bound (bfd *abfd ATTRIBUTE_UNUSED) |
| 115 | { |
| 116 | return (BIN_SYMS + 1) * sizeof (asymbol *); |
| 117 | } |
| 118 | |
| 119 | /* Create a symbol name based on the bfd's filename. */ |
| 120 | |
| 121 | static char * |
| 122 | mangle_name (bfd *abfd, char *suffix) |
| 123 | { |
| 124 | bfd_size_type size; |
| 125 | char *buf; |
| 126 | char *p; |
| 127 | |
| 128 | size = (strlen (bfd_get_filename (abfd)) |
| 129 | + strlen (suffix) |
| 130 | + sizeof "_binary__"); |
| 131 | |
| 132 | buf = (char *) bfd_alloc (abfd, size); |
| 133 | if (buf == NULL) |
| 134 | return ""; |
| 135 | |
| 136 | sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix); |
| 137 | |
| 138 | /* Change any non-alphanumeric characters to underscores. */ |
| 139 | for (p = buf; *p; p++) |
| 140 | if (! ISALNUM (*p)) |
| 141 | *p = '_'; |
| 142 | |
| 143 | return buf; |
| 144 | } |
| 145 | |
| 146 | /* Return the symbol table. */ |
| 147 | |
| 148 | static long |
| 149 | binary_canonicalize_symtab (bfd *abfd, asymbol **alocation) |
| 150 | { |
| 151 | asection *sec = (asection *) abfd->tdata.any; |
| 152 | asymbol *syms; |
| 153 | unsigned int i; |
| 154 | bfd_size_type amt = BIN_SYMS * sizeof (asymbol); |
| 155 | |
| 156 | syms = (asymbol *) bfd_alloc (abfd, amt); |
| 157 | if (syms == NULL) |
| 158 | return -1; |
| 159 | |
| 160 | /* Start symbol. */ |
| 161 | syms[0].the_bfd = abfd; |
| 162 | syms[0].name = mangle_name (abfd, "start"); |
| 163 | syms[0].value = 0; |
| 164 | syms[0].flags = BSF_GLOBAL; |
| 165 | syms[0].section = sec; |
| 166 | syms[0].udata.p = NULL; |
| 167 | |
| 168 | /* End symbol. */ |
| 169 | syms[1].the_bfd = abfd; |
| 170 | syms[1].name = mangle_name (abfd, "end"); |
| 171 | syms[1].value = sec->size; |
| 172 | syms[1].flags = BSF_GLOBAL; |
| 173 | syms[1].section = sec; |
| 174 | syms[1].udata.p = NULL; |
| 175 | |
| 176 | /* Size symbol. */ |
| 177 | syms[2].the_bfd = abfd; |
| 178 | syms[2].name = mangle_name (abfd, "size"); |
| 179 | syms[2].value = sec->size; |
| 180 | syms[2].flags = BSF_GLOBAL; |
| 181 | syms[2].section = bfd_abs_section_ptr; |
| 182 | syms[2].udata.p = NULL; |
| 183 | |
| 184 | for (i = 0; i < BIN_SYMS; i++) |
| 185 | *alocation++ = syms++; |
| 186 | *alocation = NULL; |
| 187 | |
| 188 | return BIN_SYMS; |
| 189 | } |
| 190 | |
| 191 | #define binary_make_empty_symbol _bfd_generic_make_empty_symbol |
| 192 | #define binary_print_symbol _bfd_nosymbols_print_symbol |
| 193 | #define binary_get_symbol_version_string \ |
| 194 | _bfd_nosymbols_get_symbol_version_string |
| 195 | |
| 196 | /* Get information about a symbol. */ |
| 197 | |
| 198 | static void |
| 199 | binary_get_symbol_info (bfd *ignore_abfd ATTRIBUTE_UNUSED, |
| 200 | asymbol *symbol, |
| 201 | symbol_info *ret) |
| 202 | { |
| 203 | bfd_symbol_info (symbol, ret); |
| 204 | } |
| 205 | |
| 206 | #define binary_bfd_is_local_label_name bfd_generic_is_local_label_name |
| 207 | #define binary_get_lineno _bfd_nosymbols_get_lineno |
| 208 | #define binary_find_nearest_line _bfd_nosymbols_find_nearest_line |
| 209 | #define binary_find_line _bfd_nosymbols_find_line |
| 210 | #define binary_find_inliner_info _bfd_nosymbols_find_inliner_info |
| 211 | #define binary_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol |
| 212 | #define binary_read_minisymbols _bfd_generic_read_minisymbols |
| 213 | #define binary_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol |
| 214 | #define binary_bfd_is_target_special_symbol _bfd_bool_bfd_asymbol_false |
| 215 | |
| 216 | /* Set the architecture of a binary file. */ |
| 217 | #define binary_set_arch_mach _bfd_generic_set_arch_mach |
| 218 | |
| 219 | /* Write section contents of a binary file. */ |
| 220 | |
| 221 | static bfd_boolean |
| 222 | binary_set_section_contents (bfd *abfd, |
| 223 | asection *sec, |
| 224 | const void * data, |
| 225 | file_ptr offset, |
| 226 | bfd_size_type size) |
| 227 | { |
| 228 | if (size == 0) |
| 229 | return TRUE; |
| 230 | |
| 231 | if (! abfd->output_has_begun) |
| 232 | { |
| 233 | bfd_boolean found_low; |
| 234 | bfd_vma low; |
| 235 | asection *s; |
| 236 | |
| 237 | /* The lowest section LMA sets the virtual address of the start |
| 238 | of the file. We use this to set the file position of all the |
| 239 | sections. */ |
| 240 | found_low = FALSE; |
| 241 | low = 0; |
| 242 | for (s = abfd->sections; s != NULL; s = s->next) |
| 243 | if (((s->flags |
| 244 | & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD)) |
| 245 | == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC)) |
| 246 | && (s->size > 0) |
| 247 | && (! found_low || s->lma < low)) |
| 248 | { |
| 249 | low = s->lma; |
| 250 | found_low = TRUE; |
| 251 | } |
| 252 | |
| 253 | for (s = abfd->sections; s != NULL; s = s->next) |
| 254 | { |
| 255 | unsigned int opb = bfd_octets_per_byte (abfd, s); |
| 256 | |
| 257 | s->filepos = (s->lma - low) * opb; |
| 258 | |
| 259 | /* Skip following warning check for sections that will not |
| 260 | occupy file space. */ |
| 261 | if ((s->flags |
| 262 | & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_NEVER_LOAD)) |
| 263 | != (SEC_HAS_CONTENTS | SEC_ALLOC) |
| 264 | || (s->size == 0)) |
| 265 | continue; |
| 266 | |
| 267 | /* If attempting to generate a binary file from a bfd with |
| 268 | LMA's all over the place, huge (sparse?) binary files may |
| 269 | result. This condition attempts to detect this situation |
| 270 | and print a warning. Better heuristics would be nice to |
| 271 | have. */ |
| 272 | |
| 273 | if (s->filepos < 0) |
| 274 | _bfd_error_handler |
| 275 | /* xgettext:c-format */ |
| 276 | (_("warning: writing section `%pA' at huge (ie negative) " |
| 277 | "file offset"), |
| 278 | s); |
| 279 | } |
| 280 | |
| 281 | abfd->output_has_begun = TRUE; |
| 282 | } |
| 283 | |
| 284 | /* We don't want to output anything for a section that is neither |
| 285 | loaded nor allocated. The contents of such a section are not |
| 286 | meaningful in the binary format. */ |
| 287 | if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0) |
| 288 | return TRUE; |
| 289 | if ((sec->flags & SEC_NEVER_LOAD) != 0) |
| 290 | return TRUE; |
| 291 | |
| 292 | return _bfd_generic_set_section_contents (abfd, sec, data, offset, size); |
| 293 | } |
| 294 | |
| 295 | /* No space is required for header information. */ |
| 296 | |
| 297 | static int |
| 298 | binary_sizeof_headers (bfd *abfd ATTRIBUTE_UNUSED, |
| 299 | struct bfd_link_info *info ATTRIBUTE_UNUSED) |
| 300 | { |
| 301 | return 0; |
| 302 | } |
| 303 | |
| 304 | #define binary_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents |
| 305 | #define binary_bfd_relax_section bfd_generic_relax_section |
| 306 | #define binary_bfd_gc_sections bfd_generic_gc_sections |
| 307 | #define binary_bfd_lookup_section_flags bfd_generic_lookup_section_flags |
| 308 | #define binary_bfd_merge_sections bfd_generic_merge_sections |
| 309 | #define binary_bfd_is_group_section bfd_generic_is_group_section |
| 310 | #define binary_bfd_group_name bfd_generic_group_name |
| 311 | #define binary_bfd_discard_group bfd_generic_discard_group |
| 312 | #define binary_section_already_linked _bfd_generic_section_already_linked |
| 313 | #define binary_bfd_define_common_symbol bfd_generic_define_common_symbol |
| 314 | #define binary_bfd_link_hide_symbol _bfd_generic_link_hide_symbol |
| 315 | #define binary_bfd_define_start_stop bfd_generic_define_start_stop |
| 316 | #define binary_bfd_link_hash_table_create _bfd_generic_link_hash_table_create |
| 317 | #define binary_bfd_link_just_syms _bfd_generic_link_just_syms |
| 318 | #define binary_bfd_copy_link_hash_symbol_type _bfd_generic_copy_link_hash_symbol_type |
| 319 | #define binary_bfd_link_add_symbols _bfd_generic_link_add_symbols |
| 320 | #define binary_bfd_final_link _bfd_generic_final_link |
| 321 | #define binary_bfd_link_split_section _bfd_generic_link_split_section |
| 322 | #define binary_get_section_contents_in_window _bfd_generic_get_section_contents_in_window |
| 323 | #define binary_bfd_link_check_relocs _bfd_generic_link_check_relocs |
| 324 | |
| 325 | const bfd_target binary_vec = |
| 326 | { |
| 327 | "binary", /* name */ |
| 328 | bfd_target_unknown_flavour, /* flavour */ |
| 329 | BFD_ENDIAN_UNKNOWN, /* byteorder */ |
| 330 | BFD_ENDIAN_UNKNOWN, /* header_byteorder */ |
| 331 | EXEC_P, /* object_flags */ |
| 332 | (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_DATA |
| 333 | | SEC_ROM | SEC_HAS_CONTENTS), /* section_flags */ |
| 334 | 0, /* symbol_leading_char */ |
| 335 | ' ', /* ar_pad_char */ |
| 336 | 16, /* ar_max_namelen */ |
| 337 | 255, /* match priority. */ |
| 338 | bfd_getb64, bfd_getb_signed_64, bfd_putb64, |
| 339 | bfd_getb32, bfd_getb_signed_32, bfd_putb32, |
| 340 | bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */ |
| 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, /* hdrs */ |
| 344 | { /* bfd_check_format */ |
| 345 | _bfd_dummy_target, |
| 346 | binary_object_p, |
| 347 | _bfd_dummy_target, |
| 348 | _bfd_dummy_target, |
| 349 | }, |
| 350 | { /* bfd_set_format */ |
| 351 | _bfd_bool_bfd_false_error, |
| 352 | binary_mkobject, |
| 353 | _bfd_bool_bfd_false_error, |
| 354 | _bfd_bool_bfd_false_error, |
| 355 | }, |
| 356 | { /* bfd_write_contents */ |
| 357 | _bfd_bool_bfd_false_error, |
| 358 | _bfd_bool_bfd_true, |
| 359 | _bfd_bool_bfd_false_error, |
| 360 | _bfd_bool_bfd_false_error, |
| 361 | }, |
| 362 | |
| 363 | BFD_JUMP_TABLE_GENERIC (binary), |
| 364 | BFD_JUMP_TABLE_COPY (_bfd_generic), |
| 365 | BFD_JUMP_TABLE_CORE (_bfd_nocore), |
| 366 | BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), |
| 367 | BFD_JUMP_TABLE_SYMBOLS (binary), |
| 368 | BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), |
| 369 | BFD_JUMP_TABLE_WRITE (binary), |
| 370 | BFD_JUMP_TABLE_LINK (binary), |
| 371 | BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), |
| 372 | |
| 373 | NULL, |
| 374 | |
| 375 | NULL |
| 376 | }; |