bfd/
[binutils.git] / bfd / binary.c
blob458626f02a35ceb29bd416b1d2e9c4446b34d839
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>
6 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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. */
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.
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. */
35 #include "bfd.h"
36 #include "sysdep.h"
37 #include "safe-ctype.h"
38 #include "libbfd.h"
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
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;
49 /* Create a binary object. Invoked via bfd_set_format. */
51 static bfd_boolean
52 binary_mkobject (bfd *abfd ATTRIBUTE_UNUSED)
54 return TRUE;
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. */
61 static const bfd_target *
62 binary_object_p (bfd *abfd)
64 struct stat statbuf;
65 asection *sec;
67 if (abfd->target_defaulted)
69 bfd_set_error (bfd_error_wrong_format);
70 return NULL;
73 abfd->symcount = BIN_SYMS;
75 /* Find the file size. */
76 if (bfd_stat (abfd, &statbuf) < 0)
78 bfd_set_error (bfd_error_system_call);
79 return NULL;
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;
91 abfd->tdata.any = (void *) sec;
93 if (bfd_get_arch_info (abfd) != NULL)
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));
101 return abfd->xvec;
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
108 /* Get contents of the only section. */
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)
117 if (bfd_seek (abfd, offset, SEEK_SET) != 0
118 || bfd_bread (location, count, abfd) != count)
119 return FALSE;
120 return TRUE;
123 /* Return the amount of memory needed to read the symbol table. */
125 static long
126 binary_get_symtab_upper_bound (bfd *abfd ATTRIBUTE_UNUSED)
128 return (BIN_SYMS + 1) * sizeof (asymbol *);
131 /* Create a symbol name based on the bfd's filename. */
133 static char *
134 mangle_name (bfd *abfd, char *suffix)
136 bfd_size_type size;
137 char *buf;
138 char *p;
140 size = (strlen (bfd_get_filename (abfd))
141 + strlen (suffix)
142 + sizeof "_binary__");
144 buf = bfd_alloc (abfd, size);
145 if (buf == NULL)
146 return "";
148 sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix);
150 /* Change any non-alphanumeric characters to underscores. */
151 for (p = buf; *p; p++)
152 if (! ISALNUM (*p))
153 *p = '_';
155 return buf;
158 /* Return the symbol table. */
160 static long
161 binary_canonicalize_symtab (bfd *abfd, asymbol **alocation)
163 asection *sec = (asection *) abfd->tdata.any;
164 asymbol *syms;
165 unsigned int i;
166 bfd_size_type amt = BIN_SYMS * sizeof (asymbol);
168 syms = bfd_alloc (abfd, amt);
169 if (syms == NULL)
170 return 0;
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;
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;
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;
196 for (i = 0; i < BIN_SYMS; i++)
197 *alocation++ = syms++;
198 *alocation = NULL;
200 return BIN_SYMS;
203 #define binary_make_empty_symbol _bfd_generic_make_empty_symbol
204 #define binary_print_symbol _bfd_nosymbols_print_symbol
206 /* Get information about a symbol. */
208 static void
209 binary_get_symbol_info (bfd *ignore_abfd ATTRIBUTE_UNUSED,
210 asymbol *symbol,
211 symbol_info *ret)
213 bfd_symbol_info (symbol, ret);
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)
228 /* Set the architecture of a binary file. */
229 #define binary_set_arch_mach _bfd_generic_set_arch_mach
231 /* Write section contents of a binary file. */
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)
240 if (size == 0)
241 return TRUE;
243 if (! abfd->output_has_begun)
245 bfd_boolean found_low;
246 bfd_vma low;
247 asection *s;
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))
261 low = s->lma;
262 found_low = TRUE;
265 for (s = abfd->sections; s != NULL; s = s->next)
267 s->filepos = s->lma - low;
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;
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. */
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);
290 abfd->output_has_begun = TRUE;
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;
301 return _bfd_generic_set_section_contents (abfd, sec, data, offset, size);
304 /* No space is required for header information. */
306 static int
307 binary_sizeof_headers (bfd *abfd ATTRIBUTE_UNUSED,
308 bfd_boolean exec ATTRIBUTE_UNUSED)
310 return 0;
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
328 const bfd_target binary_vec =
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,
352 { /* bfd_set_format */
353 bfd_false,
354 binary_mkobject,
355 bfd_false,
356 bfd_false,
358 { /* bfd_write_contents */
359 bfd_false,
360 bfd_true,
361 bfd_false,
362 bfd_false,
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),
375 NULL,
377 NULL