1/* BFD back-end for binary objects. 2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 3 2004, 2005, 2006, 2007, 2009 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 3 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, 21 MA 02110-1301, USA. */ 22 23/* This is a BFD backend which may be used to write binary objects. 24 It may only be used for output, not input. The intention is that 25 this may be used as an output format for objcopy in order to 26 generate raw binary data. 27 28 This is very simple. The only complication is that the real data 29 will start at some address X, and in some cases we will not want to 30 include X zeroes just to get to that point. Since the start 31 address is not meaningful for this object file format, we use it 32 instead to indicate the number of zeroes to skip at the start of 33 the file. objcopy cooperates by specially setting the start 34 address to zero by default. */ 35 36#include "sysdep.h" 37#include "bfd.h" 38#include "safe-ctype.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/* Create a binary object. Invoked via bfd_set_format. */ 46 47static bfd_boolean 48binary_mkobject (bfd *abfd ATTRIBUTE_UNUSED) 49{ 50 return TRUE; 51} 52 53/* Any file may be considered to be a binary file, provided the target 54 was not defaulted. That is, it must be explicitly specified as 55 being binary. */ 56 57static const bfd_target * 58binary_object_p (bfd *abfd) 59{ 60 struct stat statbuf; 61 asection *sec; 62 flagword flags; 63 64 if (abfd->target_defaulted) 65 { 66 bfd_set_error (bfd_error_wrong_format); 67 return NULL; 68 } 69 70 abfd->symcount = BIN_SYMS; 71 72 /* Find the file size. */ 73 if (bfd_stat (abfd, &statbuf) < 0) 74 { 75 bfd_set_error (bfd_error_system_call); 76 return NULL; 77 } 78 79 /* One data section. */ 80 flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS; 81 sec = bfd_make_section_with_flags (abfd, ".data", flags); 82 if (sec == NULL) 83 return NULL; 84 sec->vma = 0; 85 sec->size = statbuf.st_size; 86 sec->filepos = 0; 87 88 abfd->tdata.any = (void *) sec; 89 90 return abfd->xvec; 91} 92 93#define binary_close_and_cleanup _bfd_generic_close_and_cleanup 94#define binary_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 95#define binary_new_section_hook _bfd_generic_new_section_hook 96 97/* Get contents of the only section. */ 98 99static bfd_boolean 100binary_get_section_contents (bfd *abfd, 101 asection *section ATTRIBUTE_UNUSED, 102 void * location, 103 file_ptr offset, 104 bfd_size_type count) 105{ 106 if (bfd_seek (abfd, offset, SEEK_SET) != 0 107 || bfd_bread (location, count, abfd) != count) 108 return FALSE; 109 return TRUE; 110} 111 112/* Return the amount of memory needed to read the symbol table. */ 113 114static long 115binary_get_symtab_upper_bound (bfd *abfd ATTRIBUTE_UNUSED) 116{ 117 return (BIN_SYMS + 1) * sizeof (asymbol *); 118} 119 120/* Create a symbol name based on the bfd's filename. */ 121 122static char * 123mangle_name (bfd *abfd, char *suffix) 124{ 125 bfd_size_type size; 126 char *buf; 127 char *p; 128 129 size = (strlen (bfd_get_filename (abfd)) 130 + strlen (suffix) 131 + sizeof "_binary__"); 132 133 buf = (char *) bfd_alloc (abfd, size); 134 if (buf == NULL) 135 return ""; 136 137 sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix); 138 139 /* Change any non-alphanumeric characters to underscores. */ 140 for (p = buf; *p; p++) 141 if (! ISALNUM (*p)) 142 *p = '_'; 143 144 return buf; 145} 146 147/* Return the symbol table. */ 148 149static long 150binary_canonicalize_symtab (bfd *abfd, asymbol **alocation) 151{ 152 asection *sec = (asection *) abfd->tdata.any; 153 asymbol *syms; 154 unsigned int i; 155 bfd_size_type amt = BIN_SYMS * sizeof (asymbol); 156 157 syms = (asymbol *) bfd_alloc (abfd, amt); 158 if (syms == NULL) 159 return -1; 160 161 /* Start symbol. */ 162 syms[0].the_bfd = abfd; 163 syms[0].name = mangle_name (abfd, "start"); 164 syms[0].value = 0; 165 syms[0].flags = BSF_GLOBAL; 166 syms[0].section = sec; 167 syms[0].udata.p = NULL; 168 169 /* End symbol. */ 170 syms[1].the_bfd = abfd; 171 syms[1].name = mangle_name (abfd, "end"); 172 syms[1].value = sec->size; 173 syms[1].flags = BSF_GLOBAL; 174 syms[1].section = sec; 175 syms[1].udata.p = NULL; 176 177 /* Size symbol. */ 178 syms[2].the_bfd = abfd; 179 syms[2].name = mangle_name (abfd, "size"); 180 syms[2].value = sec->size; 181 syms[2].flags = BSF_GLOBAL; 182 syms[2].section = bfd_abs_section_ptr; 183 syms[2].udata.p = NULL; 184 185 for (i = 0; i < BIN_SYMS; i++) 186 *alocation++ = syms++; 187 *alocation = NULL; 188 189 return BIN_SYMS; 190} 191 192#define binary_make_empty_symbol _bfd_generic_make_empty_symbol 193#define binary_print_symbol _bfd_nosymbols_print_symbol 194 195/* Get information about a symbol. */ 196 197static void 198binary_get_symbol_info (bfd *ignore_abfd ATTRIBUTE_UNUSED, 199 asymbol *symbol, 200 symbol_info *ret) 201{ 202 bfd_symbol_info (symbol, ret); 203} 204 205#define binary_bfd_is_local_label_name bfd_generic_is_local_label_name 206#define binary_get_lineno _bfd_nosymbols_get_lineno 207#define binary_find_nearest_line _bfd_nosymbols_find_nearest_line 208#define binary_find_inliner_info _bfd_nosymbols_find_inliner_info 209#define binary_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 210#define binary_read_minisymbols _bfd_generic_read_minisymbols 211#define binary_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol 212#define binary_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false) 213 214/* Set the architecture of a binary file. */ 215#define binary_set_arch_mach _bfd_generic_set_arch_mach 216 217/* Write section contents of a binary file. */ 218 219static bfd_boolean 220binary_set_section_contents (bfd *abfd, 221 asection *sec, 222 const void * data, 223 file_ptr offset, 224 bfd_size_type size) 225{ 226 if (size == 0) 227 return TRUE; 228 229 if (! abfd->output_has_begun) 230 { 231 bfd_boolean found_low; 232 bfd_vma low; 233 asection *s; 234 235 /* The lowest section LMA sets the virtual address of the start 236 of the file. We use this to set the file position of all the 237 sections. */ 238 found_low = FALSE; 239 low = 0; 240 for (s = abfd->sections; s != NULL; s = s->next) 241 if (((s->flags 242 & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD)) 243 == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC)) 244 && (s->size > 0) 245 && (! found_low || s->lma < low)) 246 { 247 low = s->lma; 248 found_low = TRUE; 249 } 250 251 for (s = abfd->sections; s != NULL; s = s->next) 252 { 253 s->filepos = s->lma - low; 254 255 /* Skip following warning check for sections that will not 256 occupy file space. */ 257 if ((s->flags 258 & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_NEVER_LOAD)) 259 != (SEC_HAS_CONTENTS | SEC_ALLOC) 260 || (s->size == 0)) 261 continue; 262 263 /* If attempting to generate a binary file from a bfd with 264 LMA's all over the place, huge (sparse?) binary files may 265 result. This condition attempts to detect this situation 266 and print a warning. Better heuristics would be nice to 267 have. */ 268 269 if (s->filepos < 0) 270 (*_bfd_error_handler) 271 (_("Warning: Writing section `%s' to huge (ie negative) file offset 0x%lx."), 272 bfd_get_section_name (abfd, s), 273 (unsigned long) s->filepos); 274 } 275 276 abfd->output_has_begun = TRUE; 277 } 278 279 /* We don't want to output anything for a section that is neither 280 loaded nor allocated. The contents of such a section are not 281 meaningful in the binary format. */ 282 if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0) 283 return TRUE; 284 if ((sec->flags & SEC_NEVER_LOAD) != 0) 285 return TRUE; 286 287 return _bfd_generic_set_section_contents (abfd, sec, data, offset, size); 288} 289 290/* No space is required for header information. */ 291 292static int 293binary_sizeof_headers (bfd *abfd ATTRIBUTE_UNUSED, 294 struct bfd_link_info *info ATTRIBUTE_UNUSED) 295{ 296 return 0; 297} 298 299#define binary_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents 300#define binary_bfd_relax_section bfd_generic_relax_section 301#define binary_bfd_gc_sections bfd_generic_gc_sections 302#define binary_bfd_merge_sections bfd_generic_merge_sections 303#define binary_bfd_is_group_section bfd_generic_is_group_section 304#define binary_bfd_discard_group bfd_generic_discard_group 305#define binary_section_already_linked _bfd_generic_section_already_linked 306#define binary_bfd_define_common_symbol bfd_generic_define_common_symbol 307#define binary_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 308#define binary_bfd_link_hash_table_free _bfd_generic_link_hash_table_free 309#define binary_bfd_link_just_syms _bfd_generic_link_just_syms 310#define binary_bfd_copy_link_hash_symbol_type \ 311 _bfd_generic_copy_link_hash_symbol_type 312#define binary_bfd_link_add_symbols _bfd_generic_link_add_symbols 313#define binary_bfd_final_link _bfd_generic_final_link 314#define binary_bfd_link_split_section _bfd_generic_link_split_section 315#define binary_get_section_contents_in_window _bfd_generic_get_section_contents_in_window 316 317const bfd_target binary_vec = 318{ 319 "binary", /* name */ 320 bfd_target_unknown_flavour, /* flavour */ 321 BFD_ENDIAN_UNKNOWN, /* byteorder */ 322 BFD_ENDIAN_UNKNOWN, /* header_byteorder */ 323 EXEC_P, /* object_flags */ 324 (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_DATA 325 | SEC_ROM | SEC_HAS_CONTENTS), /* section_flags */ 326 0, /* symbol_leading_char */ 327 ' ', /* ar_pad_char */ 328 16, /* ar_max_namelen */ 329 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 330 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 331 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */ 332 bfd_getb64, bfd_getb_signed_64, bfd_putb64, 333 bfd_getb32, bfd_getb_signed_32, bfd_putb32, 334 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */ 335 { /* bfd_check_format */ 336 _bfd_dummy_target, 337 binary_object_p, 338 _bfd_dummy_target, 339 _bfd_dummy_target, 340 }, 341 { /* bfd_set_format */ 342 bfd_false, 343 binary_mkobject, 344 bfd_false, 345 bfd_false, 346 }, 347 { /* bfd_write_contents */ 348 bfd_false, 349 bfd_true, 350 bfd_false, 351 bfd_false, 352 }, 353 354 BFD_JUMP_TABLE_GENERIC (binary), 355 BFD_JUMP_TABLE_COPY (_bfd_generic), 356 BFD_JUMP_TABLE_CORE (_bfd_nocore), 357 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 358 BFD_JUMP_TABLE_SYMBOLS (binary), 359 BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), 360 BFD_JUMP_TABLE_WRITE (binary), 361 BFD_JUMP_TABLE_LINK (binary), 362 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 363 364 NULL, 365 366 NULL 367}; 368