1 /* BFD back-end for binary objects.
2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
3 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
4 Written by Ian Lance Taylor, Cygnus Support, <[email protected]>
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 "sysdep.h"
36 #include "bfd.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
binary_mkobject(bfd * abfd ATTRIBUTE_UNUSED)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 *
binary_object_p(bfd * abfd)62 binary_object_p (bfd *abfd)
63 {
64 struct stat statbuf;
65 asection *sec;
66 flagword flags;
67
68 if (abfd->target_defaulted)
69 {
70 bfd_set_error (bfd_error_wrong_format);
71 return NULL;
72 }
73
74 abfd->symcount = BIN_SYMS;
75
76 /* Find the file size. */
77 if (bfd_stat (abfd, &statbuf) < 0)
78 {
79 bfd_set_error (bfd_error_system_call);
80 return NULL;
81 }
82
83 /* One data section. */
84 flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS;
85 sec = bfd_make_section_with_flags (abfd, ".data", flags);
86 if (sec == NULL)
87 return NULL;
88 sec->vma = 0;
89 sec->size = statbuf.st_size;
90 sec->filepos = 0;
91
92 abfd->tdata.any = (void *) sec;
93
94 if (bfd_get_arch_info (abfd) != NULL)
95 {
96 if ((bfd_get_arch_info (abfd)->arch == bfd_arch_unknown)
97 && (bfd_external_binary_architecture != bfd_arch_unknown))
98 bfd_set_arch_info (abfd, bfd_lookup_arch
99 (bfd_external_binary_architecture, bfd_external_machine));
100 }
101
102 return abfd->xvec;
103 }
104
105 #define binary_close_and_cleanup _bfd_generic_close_and_cleanup
106 #define binary_bfd_free_cached_info _bfd_generic_bfd_free_cached_info
107 #define binary_new_section_hook _bfd_generic_new_section_hook
108
109 /* Get contents of the only section. */
110
111 static bfd_boolean
binary_get_section_contents(bfd * abfd,asection * section ATTRIBUTE_UNUSED,void * location,file_ptr offset,bfd_size_type count)112 binary_get_section_contents (bfd *abfd,
113 asection *section ATTRIBUTE_UNUSED,
114 void * location,
115 file_ptr offset,
116 bfd_size_type count)
117 {
118 if (bfd_seek (abfd, offset, SEEK_SET) != 0
119 || bfd_bread (location, count, abfd) != count)
120 return FALSE;
121 return TRUE;
122 }
123
124 /* Return the amount of memory needed to read the symbol table. */
125
126 static long
binary_get_symtab_upper_bound(bfd * abfd ATTRIBUTE_UNUSED)127 binary_get_symtab_upper_bound (bfd *abfd ATTRIBUTE_UNUSED)
128 {
129 return (BIN_SYMS + 1) * sizeof (asymbol *);
130 }
131
132 /* Create a symbol name based on the bfd's filename. */
133
134 static char *
mangle_name(bfd * abfd,char * suffix)135 mangle_name (bfd *abfd, char *suffix)
136 {
137 bfd_size_type size;
138 char *buf;
139 char *p;
140
141 size = (strlen (bfd_get_filename (abfd))
142 + strlen (suffix)
143 + sizeof "_binary__");
144
145 buf = bfd_alloc (abfd, size);
146 if (buf == NULL)
147 return "";
148
149 sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix);
150
151 /* Change any non-alphanumeric characters to underscores. */
152 for (p = buf; *p; p++)
153 if (! ISALNUM (*p))
154 *p = '_';
155
156 return buf;
157 }
158
159 /* Return the symbol table. */
160
161 static long
binary_canonicalize_symtab(bfd * abfd,asymbol ** alocation)162 binary_canonicalize_symtab (bfd *abfd, asymbol **alocation)
163 {
164 asection *sec = (asection *) abfd->tdata.any;
165 asymbol *syms;
166 unsigned int i;
167 bfd_size_type amt = BIN_SYMS * sizeof (asymbol);
168
169 syms = bfd_alloc (abfd, amt);
170 if (syms == NULL)
171 return 0;
172
173 /* Start symbol. */
174 syms[0].the_bfd = abfd;
175 syms[0].name = mangle_name (abfd, "start");
176 syms[0].value = 0;
177 syms[0].flags = BSF_GLOBAL;
178 syms[0].section = sec;
179 syms[0].udata.p = NULL;
180
181 /* End symbol. */
182 syms[1].the_bfd = abfd;
183 syms[1].name = mangle_name (abfd, "end");
184 syms[1].value = sec->size;
185 syms[1].flags = BSF_GLOBAL;
186 syms[1].section = sec;
187 syms[1].udata.p = NULL;
188
189 /* Size symbol. */
190 syms[2].the_bfd = abfd;
191 syms[2].name = mangle_name (abfd, "size");
192 syms[2].value = sec->size;
193 syms[2].flags = BSF_GLOBAL;
194 syms[2].section = bfd_abs_section_ptr;
195 syms[2].udata.p = NULL;
196
197 for (i = 0; i < BIN_SYMS; i++)
198 *alocation++ = syms++;
199 *alocation = NULL;
200
201 return BIN_SYMS;
202 }
203
204 #define binary_make_empty_symbol _bfd_generic_make_empty_symbol
205 #define binary_print_symbol _bfd_nosymbols_print_symbol
206
207 /* Get information about a symbol. */
208
209 static void
binary_get_symbol_info(bfd * ignore_abfd ATTRIBUTE_UNUSED,asymbol * symbol,symbol_info * ret)210 binary_get_symbol_info (bfd *ignore_abfd ATTRIBUTE_UNUSED,
211 asymbol *symbol,
212 symbol_info *ret)
213 {
214 bfd_symbol_info (symbol, ret);
215 }
216
217 #define binary_bfd_is_local_label_name bfd_generic_is_local_label_name
218 #define binary_get_lineno _bfd_nosymbols_get_lineno
219 #define binary_find_nearest_line _bfd_nosymbols_find_nearest_line
220 #define binary_find_inliner_info _bfd_nosymbols_find_inliner_info
221 #define binary_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol
222 #define binary_read_minisymbols _bfd_generic_read_minisymbols
223 #define binary_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol
224 #define binary_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false)
225
226 /* Set the architecture of a binary file. */
227 #define binary_set_arch_mach _bfd_generic_set_arch_mach
228
229 /* Write section contents of a binary file. */
230
231 static bfd_boolean
binary_set_section_contents(bfd * abfd,asection * sec,const void * data,file_ptr offset,bfd_size_type size)232 binary_set_section_contents (bfd *abfd,
233 asection *sec,
234 const void * data,
235 file_ptr offset,
236 bfd_size_type size)
237 {
238 if (size == 0)
239 return TRUE;
240
241 if (! abfd->output_has_begun)
242 {
243 bfd_boolean found_low;
244 bfd_vma low;
245 asection *s;
246
247 /* The lowest section LMA sets the virtual address of the start
248 of the file. We use this to set the file position of all the
249 sections. */
250 found_low = FALSE;
251 low = 0;
252 for (s = abfd->sections; s != NULL; s = s->next)
253 if (((s->flags
254 & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD))
255 == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC))
256 && (s->size > 0)
257 && (! found_low || s->lma < low))
258 {
259 low = s->lma;
260 found_low = TRUE;
261 }
262
263 for (s = abfd->sections; s != NULL; s = s->next)
264 {
265 s->filepos = s->lma - low;
266
267 /* Skip following warning check for sections that will not
268 occupy file space. */
269 if ((s->flags
270 & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_NEVER_LOAD))
271 != (SEC_HAS_CONTENTS | SEC_ALLOC)
272 || (s->size == 0))
273 continue;
274
275 /* If attempting to generate a binary file from a bfd with
276 LMA's all over the place, huge (sparse?) binary files may
277 result. This condition attempts to detect this situation
278 and print a warning. Better heuristics would be nice to
279 have. */
280
281 if (s->filepos < 0)
282 (*_bfd_error_handler)
283 (_("Warning: Writing section `%s' to huge (ie negative) file offset 0x%lx."),
284 bfd_get_section_name (abfd, s),
285 (unsigned long) s->filepos);
286 }
287
288 abfd->output_has_begun = TRUE;
289 }
290
291 /* We don't want to output anything for a section that is neither
292 loaded nor allocated. The contents of such a section are not
293 meaningful in the binary format. */
294 if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0)
295 return TRUE;
296 if ((sec->flags & SEC_NEVER_LOAD) != 0)
297 return TRUE;
298
299 return _bfd_generic_set_section_contents (abfd, sec, data, offset, size);
300 }
301
302 /* No space is required for header information. */
303
304 static int
binary_sizeof_headers(bfd * abfd ATTRIBUTE_UNUSED,struct bfd_link_info * info ATTRIBUTE_UNUSED)305 binary_sizeof_headers (bfd *abfd ATTRIBUTE_UNUSED,
306 struct bfd_link_info *info ATTRIBUTE_UNUSED)
307 {
308 return 0;
309 }
310
311 #define binary_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents
312 #define binary_bfd_relax_section bfd_generic_relax_section
313 #define binary_bfd_gc_sections bfd_generic_gc_sections
314 #define binary_bfd_merge_sections bfd_generic_merge_sections
315 #define binary_bfd_is_group_section bfd_generic_is_group_section
316 #define binary_bfd_discard_group bfd_generic_discard_group
317 #define binary_section_already_linked _bfd_generic_section_already_linked
318 #define binary_bfd_link_hash_table_create _bfd_generic_link_hash_table_create
319 #define binary_bfd_link_hash_table_free _bfd_generic_link_hash_table_free
320 #define binary_bfd_link_just_syms _bfd_generic_link_just_syms
321 #define binary_bfd_link_add_symbols _bfd_generic_link_add_symbols
322 #define binary_bfd_final_link _bfd_generic_final_link
323 #define binary_bfd_link_split_section _bfd_generic_link_split_section
324 #define binary_get_section_contents_in_window _bfd_generic_get_section_contents_in_window
325
326 const bfd_target binary_vec =
327 {
328 "binary", /* name */
329 bfd_target_unknown_flavour, /* flavour */
330 BFD_ENDIAN_UNKNOWN, /* byteorder */
331 BFD_ENDIAN_UNKNOWN, /* header_byteorder */
332 EXEC_P, /* object_flags */
333 (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_DATA
334 | SEC_ROM | SEC_HAS_CONTENTS), /* section_flags */
335 0, /* symbol_leading_char */
336 ' ', /* ar_pad_char */
337 16, /* ar_max_namelen */
338 bfd_getb64, bfd_getb_signed_64, bfd_putb64,
339 bfd_getb32, bfd_getb_signed_32, bfd_putb32,
340 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */
341 bfd_getb64, bfd_getb_signed_64, bfd_putb64,
342 bfd_getb32, bfd_getb_signed_32, bfd_putb32,
343 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */
344 { /* bfd_check_format */
345 _bfd_dummy_target,
346 binary_object_p,
347 _bfd_dummy_target,
348 _bfd_dummy_target,
349 },
350 { /* bfd_set_format */
351 bfd_false,
352 binary_mkobject,
353 bfd_false,
354 bfd_false,
355 },
356 { /* bfd_write_contents */
357 bfd_false,
358 bfd_true,
359 bfd_false,
360 bfd_false,
361 },
362
363 BFD_JUMP_TABLE_GENERIC (binary),
364 BFD_JUMP_TABLE_COPY (_bfd_generic),
365 BFD_JUMP_TABLE_CORE (_bfd_nocore),
366 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
367 BFD_JUMP_TABLE_SYMBOLS (binary),
368 BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
369 BFD_JUMP_TABLE_WRITE (binary),
370 BFD_JUMP_TABLE_LINK (binary),
371 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
372
373 NULL,
374
375 NULL
376 };
377