1 /* BFD back-end for binary objects. 2 Copyright 1994, 95, 96, 97, 98, 1999 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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 20 21 /* This is a BFD backend which may be used to write binary objects. 22 It may only be used for output, not input. The intention is that 23 this may be used as an output format for objcopy in order to 24 generate raw binary data. 25 26 This is very simple. The only complication is that the real data 27 will start at some address X, and in some cases we will not want to 28 include X zeroes just to get to that point. Since the start 29 address is not meaningful for this object file format, we use it 30 instead to indicate the number of zeroes to skip at the start of 31 the file. objcopy cooperates by specially setting the start 32 address to zero by default. */ 33 34 #include <ctype.h> 35 36 #include "bfd.h" 37 #include "sysdep.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 static boolean binary_mkobject PARAMS ((bfd *)); 45 static const bfd_target *binary_object_p PARAMS ((bfd *)); 46 static boolean binary_get_section_contents 47 PARAMS ((bfd *, asection *, PTR, file_ptr, bfd_size_type)); 48 static long binary_get_symtab_upper_bound PARAMS ((bfd *)); 49 static char *mangle_name PARAMS ((bfd *, char *)); 50 static long binary_get_symtab PARAMS ((bfd *, asymbol **)); 51 static asymbol *binary_make_empty_symbol PARAMS ((bfd *)); 52 static void binary_get_symbol_info PARAMS ((bfd *, asymbol *, symbol_info *)); 53 static boolean binary_set_section_contents 54 PARAMS ((bfd *, asection *, PTR, file_ptr, bfd_size_type)); 55 static int binary_sizeof_headers PARAMS ((bfd *, boolean)); 56 57 /* Create a binary object. Invoked via bfd_set_format. */ 58 59 static boolean 60 binary_mkobject (abfd) 61 bfd *abfd ATTRIBUTE_UNUSED; 62 { 63 return true; 64 } 65 66 /* Any file may be considered to be a binary file, provided the target 67 was not defaulted. That is, it must be explicitly specified as 68 being binary. */ 69 70 static const bfd_target * 71 binary_object_p (abfd) 72 bfd *abfd; 73 { 74 struct stat statbuf; 75 asection *sec; 76 77 if (abfd->target_defaulted) 78 { 79 bfd_set_error (bfd_error_wrong_format); 80 return NULL; 81 } 82 83 abfd->symcount = BIN_SYMS; 84 85 /* Find the file size. */ 86 if (bfd_stat (abfd, &statbuf) < 0) 87 { 88 bfd_set_error (bfd_error_system_call); 89 return NULL; 90 } 91 92 /* One data section. */ 93 sec = bfd_make_section (abfd, ".data"); 94 if (sec == NULL) 95 return NULL; 96 sec->flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS; 97 sec->vma = 0; 98 sec->_raw_size = statbuf.st_size; 99 sec->filepos = 0; 100 101 abfd->tdata.any = (PTR) sec; 102 103 return abfd->xvec; 104 } 105 106 #define binary_close_and_cleanup _bfd_generic_close_and_cleanup 107 #define binary_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 108 #define binary_new_section_hook _bfd_generic_new_section_hook 109 110 /* Get contents of the only section. */ 111 112 static boolean 113 binary_get_section_contents (abfd, section, location, offset, count) 114 bfd *abfd; 115 asection *section ATTRIBUTE_UNUSED; 116 PTR location; 117 file_ptr offset; 118 bfd_size_type count; 119 { 120 if (bfd_seek (abfd, offset, SEEK_SET) != 0 121 || bfd_read (location, 1, count, abfd) != count) 122 return false; 123 return true; 124 } 125 126 /* Return the amount of memory needed to read the symbol table. */ 127 128 static long 129 binary_get_symtab_upper_bound (abfd) 130 bfd *abfd ATTRIBUTE_UNUSED; 131 { 132 return (BIN_SYMS + 1) * sizeof (asymbol *); 133 } 134 135 /* Create a symbol name based on the bfd's filename. */ 136 137 static char * 138 mangle_name (abfd, suffix) 139 bfd *abfd; 140 char *suffix; 141 { 142 int size; 143 char *buf; 144 char *p; 145 146 size = (strlen (bfd_get_filename (abfd)) 147 + strlen (suffix) 148 + sizeof "_binary__"); 149 150 buf = (char *) bfd_alloc (abfd, size); 151 if (buf == NULL) 152 return ""; 153 154 sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix); 155 156 /* Change any non-alphanumeric characters to underscores. */ 157 for (p = buf; *p; p++) 158 if (! isalnum ((unsigned char) *p)) 159 *p = '_'; 160 161 return buf; 162 } 163 164 /* Return the symbol table. */ 165 166 static long 167 binary_get_symtab (abfd, alocation) 168 bfd *abfd; 169 asymbol **alocation; 170 { 171 asection *sec = (asection *) abfd->tdata.any; 172 asymbol *syms; 173 unsigned int i; 174 175 syms = (asymbol *) bfd_alloc (abfd, BIN_SYMS * sizeof (asymbol)); 176 if (syms == NULL) 177 return false; 178 179 /* Start symbol. */ 180 syms[0].the_bfd = abfd; 181 syms[0].name = mangle_name (abfd, "start"); 182 syms[0].value = 0; 183 syms[0].flags = BSF_GLOBAL; 184 syms[0].section = sec; 185 syms[0].udata.p = NULL; 186 187 /* End symbol. */ 188 syms[1].the_bfd = abfd; 189 syms[1].name = mangle_name (abfd, "end"); 190 syms[1].value = sec->_raw_size; 191 syms[1].flags = BSF_GLOBAL; 192 syms[1].section = sec; 193 syms[1].udata.p = NULL; 194 195 /* Size symbol. */ 196 syms[2].the_bfd = abfd; 197 syms[2].name = mangle_name (abfd, "size"); 198 syms[2].value = sec->_raw_size; 199 syms[2].flags = BSF_GLOBAL; 200 syms[2].section = bfd_abs_section_ptr; 201 syms[2].udata.p = NULL; 202 203 for (i = 0; i < BIN_SYMS; i++) 204 *alocation++ = syms++; 205 *alocation = NULL; 206 207 return BIN_SYMS; 208 } 209 210 /* Make an empty symbol. */ 211 212 static asymbol * 213 binary_make_empty_symbol (abfd) 214 bfd *abfd; 215 { 216 return (asymbol *) bfd_alloc (abfd, sizeof (asymbol)); 217 } 218 219 #define binary_print_symbol _bfd_nosymbols_print_symbol 220 221 /* Get information about a symbol. */ 222 223 static void 224 binary_get_symbol_info (ignore_abfd, symbol, ret) 225 bfd *ignore_abfd ATTRIBUTE_UNUSED; 226 asymbol *symbol; 227 symbol_info *ret; 228 { 229 bfd_symbol_info (symbol, ret); 230 } 231 232 #define binary_bfd_is_local_label_name bfd_generic_is_local_label_name 233 #define binary_get_lineno _bfd_nosymbols_get_lineno 234 #define binary_find_nearest_line _bfd_nosymbols_find_nearest_line 235 #define binary_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 236 #define binary_read_minisymbols _bfd_generic_read_minisymbols 237 #define binary_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol 238 239 #define binary_get_reloc_upper_bound \ 240 ((long (*) PARAMS ((bfd *, asection *))) bfd_0l) 241 #define binary_canonicalize_reloc \ 242 ((long (*) PARAMS ((bfd *, asection *, arelent **, asymbol **))) bfd_0l) 243 #define binary_bfd_reloc_type_lookup _bfd_norelocs_bfd_reloc_type_lookup 244 245 /* Set the architecture of a binary file. */ 246 #define binary_set_arch_mach _bfd_generic_set_arch_mach 247 248 /* Write section contents of a binary file. */ 249 250 static boolean 251 binary_set_section_contents (abfd, sec, data, offset, size) 252 bfd *abfd; 253 asection *sec; 254 PTR data; 255 file_ptr offset; 256 bfd_size_type size; 257 { 258 if (! abfd->output_has_begun) 259 { 260 boolean found_low; 261 bfd_vma low; 262 asection *s; 263 264 /* The lowest section LMA sets the virtual address of the start 265 of the file. We use this to set the file position of all the 266 sections. */ 267 found_low = false; 268 low = 0; 269 for (s = abfd->sections; s != NULL; s = s->next) 270 if (((s->flags 271 & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD)) 272 == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC)) 273 && (! found_low || s->lma < low)) 274 { 275 low = s->lma; 276 found_low = true; 277 } 278 279 for (s = abfd->sections; s != NULL; s = s->next) 280 { 281 s->filepos = s->lma - low; 282 283 /* Skip following warning check for sections that will not 284 occupy file space. */ 285 if ((s->flags 286 & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_NEVER_LOAD)) 287 != (SEC_HAS_CONTENTS | SEC_ALLOC)) 288 continue; 289 290 /* If attempting to generate a binary file from a bfd with 291 LMA's all over the place, huge (sparse?) binary files may 292 result. This condition attempts to detect this situation 293 and print a warning. Better heuristics would be nice to 294 have. */ 295 296 if (s->filepos < 0) 297 (*_bfd_error_handler) 298 (_("Warning: Writing section `%s' to huge (ie negative) file offset 0x%lx."), 299 bfd_get_section_name (abfd, s), 300 (unsigned long) s->filepos); 301 } 302 303 abfd->output_has_begun = true; 304 } 305 306 /* We don't want to output anything for a section that is neither 307 loaded nor allocated. The contents of such a section are not 308 meaningful in the binary format. */ 309 if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0) 310 return true; 311 if ((sec->flags & SEC_NEVER_LOAD) != 0) 312 return true; 313 314 return _bfd_generic_set_section_contents (abfd, sec, data, offset, size); 315 } 316 317 /* No space is required for header information. */ 318 319 static int 320 binary_sizeof_headers (abfd, exec) 321 bfd *abfd ATTRIBUTE_UNUSED; 322 boolean exec ATTRIBUTE_UNUSED; 323 { 324 return 0; 325 } 326 327 #define binary_bfd_get_relocated_section_contents \ 328 bfd_generic_get_relocated_section_contents 329 #define binary_bfd_relax_section bfd_generic_relax_section 330 #define binary_bfd_gc_sections bfd_generic_gc_sections 331 #define binary_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 332 #define binary_bfd_link_add_symbols _bfd_generic_link_add_symbols 333 #define binary_bfd_final_link _bfd_generic_final_link 334 #define binary_bfd_link_split_section _bfd_generic_link_split_section 335 #define binary_get_section_contents_in_window \ 336 _bfd_generic_get_section_contents_in_window 337 338 const bfd_target binary_vec = 339 { 340 "binary", /* name */ 341 bfd_target_unknown_flavour, /* flavour */ 342 BFD_ENDIAN_UNKNOWN, /* byteorder */ 343 BFD_ENDIAN_UNKNOWN, /* header_byteorder */ 344 EXEC_P, /* object_flags */ 345 (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_DATA 346 | SEC_ROM | SEC_HAS_CONTENTS), /* section_flags */ 347 0, /* symbol_leading_char */ 348 ' ', /* ar_pad_char */ 349 16, /* ar_max_namelen */ 350 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 351 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 352 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */ 353 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 354 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 355 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */ 356 { /* bfd_check_format */ 357 _bfd_dummy_target, 358 binary_object_p, /* bfd_check_format */ 359 _bfd_dummy_target, 360 _bfd_dummy_target, 361 }, 362 { /* bfd_set_format */ 363 bfd_false, 364 binary_mkobject, 365 bfd_false, 366 bfd_false, 367 }, 368 { /* bfd_write_contents */ 369 bfd_false, 370 bfd_true, 371 bfd_false, 372 bfd_false, 373 }, 374 375 BFD_JUMP_TABLE_GENERIC (binary), 376 BFD_JUMP_TABLE_COPY (_bfd_generic), 377 BFD_JUMP_TABLE_CORE (_bfd_nocore), 378 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 379 BFD_JUMP_TABLE_SYMBOLS (binary), 380 BFD_JUMP_TABLE_RELOCS (binary), 381 BFD_JUMP_TABLE_WRITE (binary), 382 BFD_JUMP_TABLE_LINK (binary), 383 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 384 385 NULL, 386 387 NULL 388 }; 389