1 /* BFD back-end for binary objects. 2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 3 2004, 2005 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. */ 46 enum bfd_architecture bfd_external_binary_architecture = bfd_arch_unknown; 47 unsigned long bfd_external_machine = 0; 48 49 /* Create a binary object. Invoked via bfd_set_format. */ 50 51 static bfd_boolean 52 binary_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 61 static const bfd_target * 62 binary_object_p (bfd *abfd) 63 { 64 struct stat statbuf; 65 asection *sec; 66 67 if (abfd->target_defaulted) 68 { 69 bfd_set_error (bfd_error_wrong_format); 70 return NULL; 71 } 72 73 abfd->symcount = BIN_SYMS; 74 75 /* Find the file size. */ 76 if (bfd_stat (abfd, &statbuf) < 0) 77 { 78 bfd_set_error (bfd_error_system_call); 79 return NULL; 80 } 81 82 /* One data section. */ 83 sec = bfd_make_section (abfd, ".data"); 84 if (sec == NULL) 85 return NULL; 86 sec->flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS; 87 sec->vma = 0; 88 sec->size = statbuf.st_size; 89 sec->filepos = 0; 90 91 abfd->tdata.any = (void *) sec; 92 93 if (bfd_get_arch_info (abfd) != NULL) 94 { 95 if ((bfd_get_arch_info (abfd)->arch == bfd_arch_unknown) 96 && (bfd_external_binary_architecture != bfd_arch_unknown)) 97 bfd_set_arch_info (abfd, bfd_lookup_arch 98 (bfd_external_binary_architecture, bfd_external_machine)); 99 } 100 101 return abfd->xvec; 102 } 103 104 #define binary_close_and_cleanup _bfd_generic_close_and_cleanup 105 #define binary_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 106 #define binary_new_section_hook _bfd_generic_new_section_hook 107 108 /* Get contents of the only section. */ 109 110 static bfd_boolean 111 binary_get_section_contents (bfd *abfd, 112 asection *section ATTRIBUTE_UNUSED, 113 void * location, 114 file_ptr offset, 115 bfd_size_type count) 116 { 117 if (bfd_seek (abfd, offset, SEEK_SET) != 0 118 || bfd_bread (location, count, abfd) != count) 119 return FALSE; 120 return TRUE; 121 } 122 123 /* Return the amount of memory needed to read the symbol table. */ 124 125 static long 126 binary_get_symtab_upper_bound (bfd *abfd ATTRIBUTE_UNUSED) 127 { 128 return (BIN_SYMS + 1) * sizeof (asymbol *); 129 } 130 131 /* Create a symbol name based on the bfd's filename. */ 132 133 static char * 134 mangle_name (bfd *abfd, char *suffix) 135 { 136 bfd_size_type size; 137 char *buf; 138 char *p; 139 140 size = (strlen (bfd_get_filename (abfd)) 141 + strlen (suffix) 142 + sizeof "_binary__"); 143 144 buf = bfd_alloc (abfd, size); 145 if (buf == NULL) 146 return ""; 147 148 sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix); 149 150 /* Change any non-alphanumeric characters to underscores. */ 151 for (p = buf; *p; p++) 152 if (! ISALNUM (*p)) 153 *p = '_'; 154 155 return buf; 156 } 157 158 /* Return the symbol table. */ 159 160 static long 161 binary_canonicalize_symtab (bfd *abfd, asymbol **alocation) 162 { 163 asection *sec = (asection *) abfd->tdata.any; 164 asymbol *syms; 165 unsigned int i; 166 bfd_size_type amt = BIN_SYMS * sizeof (asymbol); 167 168 syms = bfd_alloc (abfd, amt); 169 if (syms == NULL) 170 return 0; 171 172 /* Start symbol. */ 173 syms[0].the_bfd = abfd; 174 syms[0].name = mangle_name (abfd, "start"); 175 syms[0].value = 0; 176 syms[0].flags = BSF_GLOBAL; 177 syms[0].section = sec; 178 syms[0].udata.p = NULL; 179 180 /* End symbol. */ 181 syms[1].the_bfd = abfd; 182 syms[1].name = mangle_name (abfd, "end"); 183 syms[1].value = sec->size; 184 syms[1].flags = BSF_GLOBAL; 185 syms[1].section = sec; 186 syms[1].udata.p = NULL; 187 188 /* Size symbol. */ 189 syms[2].the_bfd = abfd; 190 syms[2].name = mangle_name (abfd, "size"); 191 syms[2].value = sec->size; 192 syms[2].flags = BSF_GLOBAL; 193 syms[2].section = bfd_abs_section_ptr; 194 syms[2].udata.p = NULL; 195 196 for (i = 0; i < BIN_SYMS; i++) 197 *alocation++ = syms++; 198 *alocation = NULL; 199 200 return BIN_SYMS; 201 } 202 203 #define binary_make_empty_symbol _bfd_generic_make_empty_symbol 204 #define binary_print_symbol _bfd_nosymbols_print_symbol 205 206 /* Get information about a symbol. */ 207 208 static void 209 binary_get_symbol_info (bfd *ignore_abfd ATTRIBUTE_UNUSED, 210 asymbol *symbol, 211 symbol_info *ret) 212 { 213 bfd_symbol_info (symbol, ret); 214 } 215 216 #define binary_bfd_is_local_label_name bfd_generic_is_local_label_name 217 #define binary_get_lineno _bfd_nosymbols_get_lineno 218 #define binary_find_nearest_line _bfd_nosymbols_find_nearest_line 219 #define binary_find_inliner_info _bfd_nosymbols_find_inliner_info 220 #define binary_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 221 #define binary_read_minisymbols _bfd_generic_read_minisymbols 222 #define binary_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol 223 #define binary_bfd_reloc_type_lookup _bfd_norelocs_bfd_reloc_type_lookup 224 #define binary_get_reloc_upper_bound ((long (*) (bfd *, asection *)) bfd_0l) 225 #define binary_canonicalize_reloc ((long (*) (bfd *, asection *, arelent **, asymbol **)) bfd_0l) 226 #define binary_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false) 227 228 /* Set the architecture of a binary file. */ 229 #define binary_set_arch_mach _bfd_generic_set_arch_mach 230 231 /* Write section contents of a binary file. */ 232 233 static bfd_boolean 234 binary_set_section_contents (bfd *abfd, 235 asection *sec, 236 const void * data, 237 file_ptr offset, 238 bfd_size_type size) 239 { 240 if (size == 0) 241 return TRUE; 242 243 if (! abfd->output_has_begun) 244 { 245 bfd_boolean found_low; 246 bfd_vma low; 247 asection *s; 248 249 /* The lowest section LMA sets the virtual address of the start 250 of the file. We use this to set the file position of all the 251 sections. */ 252 found_low = FALSE; 253 low = 0; 254 for (s = abfd->sections; s != NULL; s = s->next) 255 if (((s->flags 256 & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD)) 257 == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC)) 258 && (s->size > 0) 259 && (! found_low || s->lma < low)) 260 { 261 low = s->lma; 262 found_low = TRUE; 263 } 264 265 for (s = abfd->sections; s != NULL; s = s->next) 266 { 267 s->filepos = s->lma - low; 268 269 /* Skip following warning check for sections that will not 270 occupy file space. */ 271 if ((s->flags 272 & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_NEVER_LOAD)) 273 != (SEC_HAS_CONTENTS | SEC_ALLOC) 274 || (s->size == 0)) 275 continue; 276 277 /* If attempting to generate a binary file from a bfd with 278 LMA's all over the place, huge (sparse?) binary files may 279 result. This condition attempts to detect this situation 280 and print a warning. Better heuristics would be nice to 281 have. */ 282 283 if (s->filepos < 0) 284 (*_bfd_error_handler) 285 (_("Warning: Writing section `%s' to huge (ie negative) file offset 0x%lx."), 286 bfd_get_section_name (abfd, s), 287 (unsigned long) s->filepos); 288 } 289 290 abfd->output_has_begun = TRUE; 291 } 292 293 /* We don't want to output anything for a section that is neither 294 loaded nor allocated. The contents of such a section are not 295 meaningful in the binary format. */ 296 if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0) 297 return TRUE; 298 if ((sec->flags & SEC_NEVER_LOAD) != 0) 299 return TRUE; 300 301 return _bfd_generic_set_section_contents (abfd, sec, data, offset, size); 302 } 303 304 /* No space is required for header information. */ 305 306 static int 307 binary_sizeof_headers (bfd *abfd ATTRIBUTE_UNUSED, 308 bfd_boolean exec ATTRIBUTE_UNUSED) 309 { 310 return 0; 311 } 312 313 #define binary_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents 314 #define binary_bfd_relax_section bfd_generic_relax_section 315 #define binary_bfd_gc_sections bfd_generic_gc_sections 316 #define binary_bfd_merge_sections bfd_generic_merge_sections 317 #define binary_bfd_is_group_section bfd_generic_is_group_section 318 #define binary_bfd_discard_group bfd_generic_discard_group 319 #define binary_section_already_linked _bfd_generic_section_already_linked 320 #define binary_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 321 #define binary_bfd_link_hash_table_free _bfd_generic_link_hash_table_free 322 #define binary_bfd_link_just_syms _bfd_generic_link_just_syms 323 #define binary_bfd_link_add_symbols _bfd_generic_link_add_symbols 324 #define binary_bfd_final_link _bfd_generic_final_link 325 #define binary_bfd_link_split_section _bfd_generic_link_split_section 326 #define binary_get_section_contents_in_window _bfd_generic_get_section_contents_in_window 327 328 const bfd_target binary_vec = 329 { 330 "binary", /* name */ 331 bfd_target_unknown_flavour, /* flavour */ 332 BFD_ENDIAN_UNKNOWN, /* byteorder */ 333 BFD_ENDIAN_UNKNOWN, /* header_byteorder */ 334 EXEC_P, /* object_flags */ 335 (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_DATA 336 | SEC_ROM | SEC_HAS_CONTENTS), /* section_flags */ 337 0, /* symbol_leading_char */ 338 ' ', /* ar_pad_char */ 339 16, /* ar_max_namelen */ 340 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 341 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 342 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */ 343 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 344 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 345 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */ 346 { /* bfd_check_format */ 347 _bfd_dummy_target, 348 binary_object_p, 349 _bfd_dummy_target, 350 _bfd_dummy_target, 351 }, 352 { /* bfd_set_format */ 353 bfd_false, 354 binary_mkobject, 355 bfd_false, 356 bfd_false, 357 }, 358 { /* bfd_write_contents */ 359 bfd_false, 360 bfd_true, 361 bfd_false, 362 bfd_false, 363 }, 364 365 BFD_JUMP_TABLE_GENERIC (binary), 366 BFD_JUMP_TABLE_COPY (_bfd_generic), 367 BFD_JUMP_TABLE_CORE (_bfd_nocore), 368 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 369 BFD_JUMP_TABLE_SYMBOLS (binary), 370 BFD_JUMP_TABLE_RELOCS (binary), 371 BFD_JUMP_TABLE_WRITE (binary), 372 BFD_JUMP_TABLE_LINK (binary), 373 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 374 375 NULL, 376 377 NULL 378 }; 379