/src/binutils-gdb/bfd/binary.c
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1 | | /* BFD back-end for binary objects. |
2 | | Copyright (C) 1994-2025 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 3 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., 51 Franklin Street - Fifth Floor, Boston, |
20 | | MA 02110-1301, USA. */ |
21 | | |
22 | | /* This is a BFD backend which may be used to read or write binary |
23 | | objects. Historically, it was used as an output format for objcopy |
24 | | in order to generate raw binary data, but is now used for other |
25 | | purposes as well. |
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 | 0 | #define BIN_SYMS 3 |
43 | | |
44 | | /* Create a binary object. Invoked via bfd_set_format. */ |
45 | | |
46 | | static bool |
47 | | binary_mkobject (bfd *abfd ATTRIBUTE_UNUSED) |
48 | 0 | { |
49 | 0 | return true; |
50 | 0 | } |
51 | | |
52 | | /* Any file may be considered to be a binary file, provided the target |
53 | | was not defaulted. That is, it must be explicitly specified as |
54 | | being binary. */ |
55 | | |
56 | | static bfd_cleanup |
57 | | binary_object_p (bfd *abfd) |
58 | 0 | { |
59 | 0 | struct stat statbuf; |
60 | 0 | asection *sec; |
61 | 0 | flagword flags; |
62 | |
|
63 | 0 | if (abfd->target_defaulted) |
64 | 0 | { |
65 | 0 | bfd_set_error (bfd_error_wrong_format); |
66 | 0 | return NULL; |
67 | 0 | } |
68 | | |
69 | 0 | abfd->symcount = BIN_SYMS; |
70 | | |
71 | | /* Find the file size. */ |
72 | 0 | if (bfd_stat (abfd, &statbuf) < 0) |
73 | 0 | { |
74 | 0 | bfd_set_error (bfd_error_system_call); |
75 | 0 | return NULL; |
76 | 0 | } |
77 | | |
78 | | /* One data section. */ |
79 | 0 | flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS; |
80 | 0 | sec = bfd_make_section_with_flags (abfd, ".data", flags); |
81 | 0 | if (sec == NULL) |
82 | 0 | return NULL; |
83 | 0 | sec->vma = 0; |
84 | 0 | sec->size = statbuf.st_size; |
85 | 0 | sec->filepos = 0; |
86 | |
|
87 | 0 | abfd->tdata.any = (void *) sec; |
88 | |
|
89 | 0 | return _bfd_no_cleanup; |
90 | 0 | } |
91 | | |
92 | | #define binary_close_and_cleanup _bfd_generic_close_and_cleanup |
93 | | #define binary_bfd_free_cached_info _bfd_generic_bfd_free_cached_info |
94 | | #define binary_new_section_hook _bfd_generic_new_section_hook |
95 | | |
96 | | /* Get contents of the only section. */ |
97 | | |
98 | | static bool |
99 | | binary_get_section_contents (bfd *abfd, |
100 | | asection *section, |
101 | | void * location, |
102 | | file_ptr offset, |
103 | | bfd_size_type count) |
104 | 0 | { |
105 | 0 | if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 |
106 | 0 | || bfd_read (location, count, abfd) != count) |
107 | 0 | return false; |
108 | 0 | return true; |
109 | 0 | } |
110 | | |
111 | | /* Return the amount of memory needed to read the symbol table. */ |
112 | | |
113 | | static long |
114 | | binary_get_symtab_upper_bound (bfd *abfd ATTRIBUTE_UNUSED) |
115 | 0 | { |
116 | 0 | return (BIN_SYMS + 1) * sizeof (asymbol *); |
117 | 0 | } |
118 | | |
119 | | /* Create a symbol name based on the bfd's filename. */ |
120 | | |
121 | | static char * |
122 | | mangle_name (bfd *abfd, char *suffix) |
123 | 0 | { |
124 | 0 | bfd_size_type size; |
125 | 0 | char *buf; |
126 | 0 | char *p; |
127 | |
|
128 | 0 | size = (strlen (bfd_get_filename (abfd)) |
129 | 0 | + strlen (suffix) |
130 | 0 | + sizeof "_binary__"); |
131 | |
|
132 | 0 | buf = (char *) bfd_alloc (abfd, size); |
133 | 0 | if (buf == NULL) |
134 | 0 | return ""; |
135 | | |
136 | 0 | sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix); |
137 | | |
138 | | /* Change any non-alphanumeric characters to underscores. */ |
139 | 0 | for (p = buf; *p; p++) |
140 | 0 | if (! ISALNUM (*p)) |
141 | 0 | *p = '_'; |
142 | |
|
143 | 0 | return buf; |
144 | 0 | } |
145 | | |
146 | | /* Return the symbol table. */ |
147 | | |
148 | | static long |
149 | | binary_canonicalize_symtab (bfd *abfd, asymbol **alocation) |
150 | 0 | { |
151 | 0 | asection *sec = (asection *) abfd->tdata.any; |
152 | 0 | asymbol *syms; |
153 | 0 | unsigned int i; |
154 | 0 | size_t amt = BIN_SYMS * sizeof (asymbol); |
155 | |
|
156 | 0 | syms = (asymbol *) bfd_alloc (abfd, amt); |
157 | 0 | if (syms == NULL) |
158 | 0 | return -1; |
159 | | |
160 | | /* Start symbol. */ |
161 | 0 | syms[0].the_bfd = abfd; |
162 | 0 | syms[0].name = mangle_name (abfd, "start"); |
163 | 0 | syms[0].value = 0; |
164 | 0 | syms[0].flags = BSF_GLOBAL; |
165 | 0 | syms[0].section = sec; |
166 | 0 | syms[0].udata.p = NULL; |
167 | | |
168 | | /* End symbol. */ |
169 | 0 | syms[1].the_bfd = abfd; |
170 | 0 | syms[1].name = mangle_name (abfd, "end"); |
171 | 0 | syms[1].value = sec->size; |
172 | 0 | syms[1].flags = BSF_GLOBAL; |
173 | 0 | syms[1].section = sec; |
174 | 0 | syms[1].udata.p = NULL; |
175 | | |
176 | | /* Size symbol. */ |
177 | 0 | syms[2].the_bfd = abfd; |
178 | 0 | syms[2].name = mangle_name (abfd, "size"); |
179 | 0 | syms[2].value = sec->size; |
180 | 0 | syms[2].flags = BSF_GLOBAL; |
181 | 0 | syms[2].section = bfd_abs_section_ptr; |
182 | 0 | syms[2].udata.p = NULL; |
183 | |
|
184 | 0 | for (i = 0; i < BIN_SYMS; i++) |
185 | 0 | *alocation++ = syms++; |
186 | 0 | *alocation = NULL; |
187 | |
|
188 | 0 | return BIN_SYMS; |
189 | 0 | } |
190 | | |
191 | | #define binary_make_empty_symbol _bfd_generic_make_empty_symbol |
192 | | #define binary_print_symbol _bfd_nosymbols_print_symbol |
193 | | #define binary_get_symbol_version_string \ |
194 | | _bfd_nosymbols_get_symbol_version_string |
195 | | |
196 | | /* Get information about a symbol. */ |
197 | | |
198 | | static void |
199 | | binary_get_symbol_info (bfd *ignore_abfd ATTRIBUTE_UNUSED, |
200 | | asymbol *symbol, |
201 | | symbol_info *ret) |
202 | 0 | { |
203 | 0 | bfd_symbol_info (symbol, ret); |
204 | 0 | } |
205 | | |
206 | | #define binary_bfd_is_local_label_name bfd_generic_is_local_label_name |
207 | | #define binary_get_lineno _bfd_nosymbols_get_lineno |
208 | | #define binary_find_nearest_line _bfd_nosymbols_find_nearest_line |
209 | | #define binary_find_nearest_line_with_alt _bfd_nosymbols_find_nearest_line_with_alt |
210 | | #define binary_find_line _bfd_nosymbols_find_line |
211 | | #define binary_find_inliner_info _bfd_nosymbols_find_inliner_info |
212 | | #define binary_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol |
213 | | #define binary_read_minisymbols _bfd_generic_read_minisymbols |
214 | | #define binary_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol |
215 | | #define binary_bfd_is_target_special_symbol _bfd_bool_bfd_asymbol_false |
216 | | |
217 | | /* Set the architecture of a binary file. */ |
218 | | #define binary_set_arch_mach _bfd_generic_set_arch_mach |
219 | | |
220 | | /* Write section contents of a binary file. */ |
221 | | |
222 | | static bool |
223 | | binary_set_section_contents (bfd *abfd, |
224 | | asection *sec, |
225 | | const void * data, |
226 | | file_ptr offset, |
227 | | bfd_size_type size) |
228 | 0 | { |
229 | 0 | if (size == 0) |
230 | 0 | return true; |
231 | | |
232 | 0 | if (! abfd->output_has_begun) |
233 | 0 | { |
234 | 0 | bool found_low; |
235 | 0 | bfd_vma low; |
236 | 0 | asection *s; |
237 | | |
238 | | /* The lowest section LMA sets the virtual address of the start |
239 | | of the file. We use this to set the file position of all the |
240 | | sections. */ |
241 | 0 | found_low = false; |
242 | 0 | low = 0; |
243 | 0 | for (s = abfd->sections; s != NULL; s = s->next) |
244 | 0 | if (((s->flags |
245 | 0 | & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD)) |
246 | 0 | == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC)) |
247 | 0 | && (s->size > 0) |
248 | 0 | && (! found_low || s->lma < low)) |
249 | 0 | { |
250 | 0 | low = s->lma; |
251 | 0 | found_low = true; |
252 | 0 | } |
253 | |
|
254 | 0 | for (s = abfd->sections; s != NULL; s = s->next) |
255 | 0 | { |
256 | 0 | unsigned int opb = bfd_octets_per_byte (abfd, s); |
257 | |
|
258 | 0 | s->filepos = (s->lma - low) * opb; |
259 | | |
260 | | /* Skip following warning check for sections that will not |
261 | | occupy file space. */ |
262 | 0 | if ((s->flags |
263 | 0 | & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_NEVER_LOAD)) |
264 | 0 | != (SEC_HAS_CONTENTS | SEC_ALLOC) |
265 | 0 | || (s->size == 0)) |
266 | 0 | continue; |
267 | | |
268 | | /* If attempting to generate a binary file from a bfd with |
269 | | LMA's all over the place, huge (sparse?) binary files may |
270 | | result. This condition attempts to detect this situation |
271 | | and print a warning. Better heuristics would be nice to |
272 | | have. */ |
273 | | |
274 | 0 | if (s->filepos < 0) |
275 | 0 | _bfd_error_handler |
276 | | /* xgettext:c-format */ |
277 | 0 | (_("warning: writing section `%pA' at huge (ie negative) " |
278 | 0 | "file offset"), |
279 | 0 | s); |
280 | 0 | } |
281 | |
|
282 | 0 | abfd->output_has_begun = true; |
283 | 0 | } |
284 | | |
285 | | /* We don't want to output anything for a section that is neither |
286 | | loaded nor allocated. The contents of such a section are not |
287 | | meaningful in the binary format. */ |
288 | 0 | if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0) |
289 | 0 | return true; |
290 | 0 | if ((sec->flags & SEC_NEVER_LOAD) != 0) |
291 | 0 | return true; |
292 | | |
293 | 0 | return _bfd_generic_set_section_contents (abfd, sec, data, offset, size); |
294 | 0 | } |
295 | | |
296 | | #define binary_sizeof_headers _bfd_nolink_sizeof_headers |
297 | | #define binary_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents |
298 | | #define binary_bfd_relax_section bfd_generic_relax_section |
299 | | #define binary_bfd_gc_sections bfd_generic_gc_sections |
300 | | #define binary_bfd_lookup_section_flags bfd_generic_lookup_section_flags |
301 | | #define binary_bfd_merge_sections bfd_generic_merge_sections |
302 | | #define binary_bfd_is_group_section bfd_generic_is_group_section |
303 | | #define binary_bfd_group_name bfd_generic_group_name |
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_hide_symbol _bfd_generic_link_hide_symbol |
308 | | #define binary_bfd_define_start_stop bfd_generic_define_start_stop |
309 | | #define binary_bfd_link_hash_table_create _bfd_generic_link_hash_table_create |
310 | | #define binary_bfd_link_just_syms _bfd_generic_link_just_syms |
311 | | #define binary_bfd_copy_link_hash_symbol_type _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_bfd_link_check_relocs _bfd_generic_link_check_relocs |
316 | | |
317 | | const 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_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS |
325 | | | SEC_ALLOC | SEC_LOAD), /* section_flags */ |
326 | | 0, /* symbol_leading_char */ |
327 | | ' ', /* ar_pad_char */ |
328 | | 16, /* ar_max_namelen */ |
329 | | 255, /* match priority. */ |
330 | | TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */ |
331 | | bfd_getb64, bfd_getb_signed_64, bfd_putb64, |
332 | | bfd_getb32, bfd_getb_signed_32, bfd_putb32, |
333 | | bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */ |
334 | | bfd_getb64, bfd_getb_signed_64, bfd_putb64, |
335 | | bfd_getb32, bfd_getb_signed_32, bfd_putb32, |
336 | | bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */ |
337 | | { /* bfd_check_format */ |
338 | | _bfd_dummy_target, |
339 | | binary_object_p, |
340 | | _bfd_dummy_target, |
341 | | _bfd_dummy_target, |
342 | | }, |
343 | | { /* bfd_set_format */ |
344 | | _bfd_bool_bfd_false_error, |
345 | | binary_mkobject, |
346 | | _bfd_bool_bfd_false_error, |
347 | | _bfd_bool_bfd_false_error, |
348 | | }, |
349 | | { /* bfd_write_contents */ |
350 | | _bfd_bool_bfd_false_error, |
351 | | _bfd_bool_bfd_true, |
352 | | _bfd_bool_bfd_false_error, |
353 | | _bfd_bool_bfd_false_error, |
354 | | }, |
355 | | |
356 | | BFD_JUMP_TABLE_GENERIC (binary), |
357 | | BFD_JUMP_TABLE_COPY (_bfd_generic), |
358 | | BFD_JUMP_TABLE_CORE (_bfd_nocore), |
359 | | BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), |
360 | | BFD_JUMP_TABLE_SYMBOLS (binary), |
361 | | BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), |
362 | | BFD_JUMP_TABLE_WRITE (binary), |
363 | | BFD_JUMP_TABLE_LINK (binary), |
364 | | BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), |
365 | | |
366 | | NULL, |
367 | | |
368 | | NULL |
369 | | }; |