1 /* BFD back-end for binary objects. 2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000 3 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 <ctype.h> 36 37 #include "bfd.h" 38 #include "sysdep.h" 39 #include "libbfd.h" 40 41 /* Any bfd we create by reading a binary file has three symbols: 42 a start symbol, an end symbol, and an absolute length symbol. */ 43 #define BIN_SYMS 3 44 45 static boolean binary_mkobject PARAMS ((bfd *)); 46 static const bfd_target *binary_object_p PARAMS ((bfd *)); 47 static boolean binary_get_section_contents 48 PARAMS ((bfd *, asection *, PTR, file_ptr, bfd_size_type)); 49 static long binary_get_symtab_upper_bound PARAMS ((bfd *)); 50 static char *mangle_name PARAMS ((bfd *, char *)); 51 static long binary_get_symtab PARAMS ((bfd *, asymbol **)); 52 static asymbol *binary_make_empty_symbol PARAMS ((bfd *)); 53 static void binary_get_symbol_info PARAMS ((bfd *, asymbol *, symbol_info *)); 54 static boolean binary_set_section_contents 55 PARAMS ((bfd *, asection *, PTR, file_ptr, bfd_size_type)); 56 static int binary_sizeof_headers PARAMS ((bfd *, boolean)); 57 58 /* Create a binary object. Invoked via bfd_set_format. */ 59 60 static boolean 61 binary_mkobject (abfd) 62 bfd *abfd ATTRIBUTE_UNUSED; 63 { 64 return true; 65 } 66 67 /* Any file may be considered to be a binary file, provided the target 68 was not defaulted. That is, it must be explicitly specified as 69 being binary. */ 70 71 static const bfd_target * 72 binary_object_p (abfd) 73 bfd *abfd; 74 { 75 struct stat statbuf; 76 asection *sec; 77 78 if (abfd->target_defaulted) 79 { 80 bfd_set_error (bfd_error_wrong_format); 81 return NULL; 82 } 83 84 abfd->symcount = BIN_SYMS; 85 86 /* Find the file size. */ 87 if (bfd_stat (abfd, &statbuf) < 0) 88 { 89 bfd_set_error (bfd_error_system_call); 90 return NULL; 91 } 92 93 /* One data section. */ 94 sec = bfd_make_section (abfd, ".data"); 95 if (sec == NULL) 96 return NULL; 97 sec->flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS; 98 sec->vma = 0; 99 sec->_raw_size = statbuf.st_size; 100 sec->filepos = 0; 101 102 abfd->tdata.any = (PTR) sec; 103 104 return abfd->xvec; 105 } 106 107 #define binary_close_and_cleanup _bfd_generic_close_and_cleanup 108 #define binary_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 109 #define binary_new_section_hook _bfd_generic_new_section_hook 110 111 /* Get contents of the only section. */ 112 113 static boolean 114 binary_get_section_contents (abfd, section, location, offset, count) 115 bfd *abfd; 116 asection *section ATTRIBUTE_UNUSED; 117 PTR location; 118 file_ptr offset; 119 bfd_size_type count; 120 { 121 if (bfd_seek (abfd, offset, SEEK_SET) != 0 122 || bfd_read (location, 1, count, abfd) != count) 123 return false; 124 return true; 125 } 126 127 /* Return the amount of memory needed to read the symbol table. */ 128 129 static long 130 binary_get_symtab_upper_bound (abfd) 131 bfd *abfd ATTRIBUTE_UNUSED; 132 { 133 return (BIN_SYMS + 1) * sizeof (asymbol *); 134 } 135 136 /* Create a symbol name based on the bfd's filename. */ 137 138 static char * 139 mangle_name (abfd, suffix) 140 bfd *abfd; 141 char *suffix; 142 { 143 int size; 144 char *buf; 145 char *p; 146 147 size = (strlen (bfd_get_filename (abfd)) 148 + strlen (suffix) 149 + sizeof "_binary__"); 150 151 buf = (char *) bfd_alloc (abfd, size); 152 if (buf == NULL) 153 return ""; 154 155 sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix); 156 157 /* Change any non-alphanumeric characters to underscores. */ 158 for (p = buf; *p; p++) 159 if (! isalnum ((unsigned char) *p)) 160 *p = '_'; 161 162 return buf; 163 } 164 165 /* Return the symbol table. */ 166 167 static long 168 binary_get_symtab (abfd, alocation) 169 bfd *abfd; 170 asymbol **alocation; 171 { 172 asection *sec = (asection *) abfd->tdata.any; 173 asymbol *syms; 174 unsigned int i; 175 176 syms = (asymbol *) bfd_alloc (abfd, BIN_SYMS * sizeof (asymbol)); 177 if (syms == NULL) 178 return false; 179 180 /* Start symbol. */ 181 syms[0].the_bfd = abfd; 182 syms[0].name = mangle_name (abfd, "start"); 183 syms[0].value = 0; 184 syms[0].flags = BSF_GLOBAL; 185 syms[0].section = sec; 186 syms[0].udata.p = NULL; 187 188 /* End symbol. */ 189 syms[1].the_bfd = abfd; 190 syms[1].name = mangle_name (abfd, "end"); 191 syms[1].value = sec->_raw_size; 192 syms[1].flags = BSF_GLOBAL; 193 syms[1].section = sec; 194 syms[1].udata.p = NULL; 195 196 /* Size symbol. */ 197 syms[2].the_bfd = abfd; 198 syms[2].name = mangle_name (abfd, "size"); 199 syms[2].value = sec->_raw_size; 200 syms[2].flags = BSF_GLOBAL; 201 syms[2].section = bfd_abs_section_ptr; 202 syms[2].udata.p = NULL; 203 204 for (i = 0; i < BIN_SYMS; i++) 205 *alocation++ = syms++; 206 *alocation = NULL; 207 208 return BIN_SYMS; 209 } 210 211 /* Make an empty symbol. */ 212 213 static asymbol * 214 binary_make_empty_symbol (abfd) 215 bfd *abfd; 216 { 217 return (asymbol *) bfd_alloc (abfd, sizeof (asymbol)); 218 } 219 220 #define binary_print_symbol _bfd_nosymbols_print_symbol 221 222 /* Get information about a symbol. */ 223 224 static void 225 binary_get_symbol_info (ignore_abfd, symbol, ret) 226 bfd *ignore_abfd ATTRIBUTE_UNUSED; 227 asymbol *symbol; 228 symbol_info *ret; 229 { 230 bfd_symbol_info (symbol, ret); 231 } 232 233 #define binary_bfd_is_local_label_name bfd_generic_is_local_label_name 234 #define binary_get_lineno _bfd_nosymbols_get_lineno 235 #define binary_find_nearest_line _bfd_nosymbols_find_nearest_line 236 #define binary_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 237 #define binary_read_minisymbols _bfd_generic_read_minisymbols 238 #define binary_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol 239 240 #define binary_get_reloc_upper_bound \ 241 ((long (*) PARAMS ((bfd *, asection *))) bfd_0l) 242 #define binary_canonicalize_reloc \ 243 ((long (*) PARAMS ((bfd *, asection *, arelent **, asymbol **))) bfd_0l) 244 #define binary_bfd_reloc_type_lookup _bfd_norelocs_bfd_reloc_type_lookup 245 246 /* Set the architecture of a binary file. */ 247 #define binary_set_arch_mach _bfd_generic_set_arch_mach 248 249 /* Write section contents of a binary file. */ 250 251 static boolean 252 binary_set_section_contents (abfd, sec, data, offset, size) 253 bfd *abfd; 254 asection *sec; 255 PTR data; 256 file_ptr offset; 257 bfd_size_type size; 258 { 259 if (size == 0) 260 return true; 261 262 if (! abfd->output_has_begun) 263 { 264 boolean found_low; 265 bfd_vma low; 266 asection *s; 267 268 /* The lowest section LMA sets the virtual address of the start 269 of the file. We use this to set the file position of all the 270 sections. */ 271 found_low = false; 272 low = 0; 273 for (s = abfd->sections; s != NULL; s = s->next) 274 if (((s->flags 275 & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD)) 276 == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC)) 277 && (s->_raw_size > 0) 278 && (! found_low || s->lma < low)) 279 { 280 low = s->lma; 281 found_low = true; 282 } 283 284 for (s = abfd->sections; s != NULL; s = s->next) 285 { 286 s->filepos = s->lma - low; 287 288 /* Skip following warning check for sections that will not 289 occupy file space. */ 290 if ((s->flags 291 & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_NEVER_LOAD)) 292 != (SEC_HAS_CONTENTS | SEC_ALLOC) 293 || (s->_raw_size == 0)) 294 continue; 295 296 /* If attempting to generate a binary file from a bfd with 297 LMA's all over the place, huge (sparse?) binary files may 298 result. This condition attempts to detect this situation 299 and print a warning. Better heuristics would be nice to 300 have. */ 301 302 if (s->filepos < 0) 303 (*_bfd_error_handler) 304 (_("Warning: Writing section `%s' to huge (ie negative) file offset 0x%lx."), 305 bfd_get_section_name (abfd, s), 306 (unsigned long) s->filepos); 307 } 308 309 abfd->output_has_begun = true; 310 } 311 312 /* We don't want to output anything for a section that is neither 313 loaded nor allocated. The contents of such a section are not 314 meaningful in the binary format. */ 315 if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0) 316 return true; 317 if ((sec->flags & SEC_NEVER_LOAD) != 0) 318 return true; 319 320 return _bfd_generic_set_section_contents (abfd, sec, data, offset, size); 321 } 322 323 /* No space is required for header information. */ 324 325 static int 326 binary_sizeof_headers (abfd, exec) 327 bfd *abfd ATTRIBUTE_UNUSED; 328 boolean exec ATTRIBUTE_UNUSED; 329 { 330 return 0; 331 } 332 333 #define binary_bfd_get_relocated_section_contents \ 334 bfd_generic_get_relocated_section_contents 335 #define binary_bfd_relax_section bfd_generic_relax_section 336 #define binary_bfd_gc_sections bfd_generic_gc_sections 337 #define binary_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 338 #define binary_bfd_link_add_symbols _bfd_generic_link_add_symbols 339 #define binary_bfd_final_link _bfd_generic_final_link 340 #define binary_bfd_link_split_section _bfd_generic_link_split_section 341 #define binary_get_section_contents_in_window \ 342 _bfd_generic_get_section_contents_in_window 343 344 const bfd_target binary_vec = 345 { 346 "binary", /* name */ 347 bfd_target_unknown_flavour, /* flavour */ 348 BFD_ENDIAN_UNKNOWN, /* byteorder */ 349 BFD_ENDIAN_UNKNOWN, /* header_byteorder */ 350 EXEC_P, /* object_flags */ 351 (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_DATA 352 | SEC_ROM | SEC_HAS_CONTENTS), /* section_flags */ 353 0, /* symbol_leading_char */ 354 ' ', /* ar_pad_char */ 355 16, /* ar_max_namelen */ 356 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 357 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 358 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */ 359 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 360 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 361 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */ 362 { /* bfd_check_format */ 363 _bfd_dummy_target, 364 binary_object_p, /* bfd_check_format */ 365 _bfd_dummy_target, 366 _bfd_dummy_target, 367 }, 368 { /* bfd_set_format */ 369 bfd_false, 370 binary_mkobject, 371 bfd_false, 372 bfd_false, 373 }, 374 { /* bfd_write_contents */ 375 bfd_false, 376 bfd_true, 377 bfd_false, 378 bfd_false, 379 }, 380 381 BFD_JUMP_TABLE_GENERIC (binary), 382 BFD_JUMP_TABLE_COPY (_bfd_generic), 383 BFD_JUMP_TABLE_CORE (_bfd_nocore), 384 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 385 BFD_JUMP_TABLE_SYMBOLS (binary), 386 BFD_JUMP_TABLE_RELOCS (binary), 387 BFD_JUMP_TABLE_WRITE (binary), 388 BFD_JUMP_TABLE_LINK (binary), 389 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 390 391 NULL, 392 393 NULL 394 }; 395