1OBJCOPY(1) GNU Development Tools OBJCOPY(1)
2
6 objcopy - copy and translate object files
7
9 objcopy [-F bfdname|--target=bfdname]
10 [-I bfdname|--input-target=bfdname]
11 [-O bfdname|--output-target=bfdname]
12 [-B bfdarch|--binary-architecture=bfdarch]
13 [-S|--strip-all]
14 [-g|--strip-debug]
15 [-K symbolname|--keep-symbol=symbolname]
16 [-N symbolname|--strip-symbol=symbolname]
17 [--strip-unneeded-symbol=symbolname]
18 [-G symbolname|--keep-global-symbol=symbolname]
19 [--localize-hidden]
20 [-L symbolname|--localize-symbol=symbolname]
21 [--globalize-symbol=symbolname]
22 [-W symbolname|--weaken-symbol=symbolname]
23 [-w|--wildcard]
24 [-x|--discard-all]
25 [-X|--discard-locals]
26 [-b byte|--byte=byte]
27 [-i interleave|--interleave=interleave]
28 [-j sectionname|--only-section=sectionname]
29 [-R sectionname|--remove-section=sectionname]
30 [-p|--preserve-dates]
31 [--debugging]
32 [--gap-fill=val]
33 [--pad-to=address]
34 [--set-start=val]
35 [--adjust-start=incr]
36 [--change-addresses=incr]
37 [--change-section-address section{=,+,-}val]
38 [--change-section-lma section{=,+,-}val]
39 [--change-section-vma section{=,+,-}val]
40 [--change-warnings] [--no-change-warnings]
41 [--set-section-flags section=flags]
42 [--add-section sectionname=filename]
43 [--rename-section oldname=newname[,flags]]
44 [--long-section-names {enable,disable,keep}]
45 [--change-leading-char] [--remove-leading-char]
46 [--reverse-bytes=num]
47 [--srec-len=ival] [--srec-forceS3]
48 [--redefine-sym old=new]
49 [--redefine-syms=filename]
50 [--weaken]
51 [--keep-symbols=filename]
52 [--strip-symbols=filename]
53 [--strip-unneeded-symbols=filename]
54 [--keep-global-symbols=filename]
55 [--localize-symbols=filename]
56 [--globalize-symbols=filename]
57 [--weaken-symbols=filename]
58 [--alt-machine-code=index]
59 [--prefix-symbols=string]
60 [--prefix-sections=string]
61 [--prefix-alloc-sections=string]
62 [--add-gnu-debuglink=path-to-file]
63 [--keep-file-symbols]
64 [--only-keep-debug]
65 [--extract-symbol]
66 [--writable-text]
67 [--readonly-text]
68 [--pure]
69 [--impure]
70 [--file-alignment=num]
71 [--heap=size]
72 [--image-base=address]
73 [--section-alignment=num]
74 [--stack=size]
75 [--subsystem=which:major.minor]
76 [-v|--verbose]
77 [-V|--version]
78 [--help] [--info]
79 infile [outfile]
80
82 The GNU objcopy utility copies the contents of an object file to
83 another. objcopy uses the GNU BFD Library to read and write the object
84 files. It can write the destination object file in a format different
85 from that of the source object file. The exact behavior of objcopy is
86 controlled by command-line options. Note that objcopy should be able
87 to copy a fully linked file between any two formats. However, copying a
88 relocatable object file between any two formats may not work as
89 expected.
90 objcopy creates temporary files to do its translations and deletes them
92 afterward. objcopy uses BFD to do all its translation work; it has
93 access to all the formats described in BFD and thus is able to
94 recognize most formats without being told explicitly.
95 objcopy can be used to generate S-records by using an output target of
97 srec (e.g., use -O srec).
98 objcopy can be used to generate a raw binary file by using an output
100 target of binary (e.g., use -O binary). When objcopy generates a raw
101 binary file, it will essentially produce a memory dump of the contents
102 of the input object file. All symbols and relocation information will
103 be discarded. The memory dump will start at the load address of the
104 lowest section copied into the output file.
105 When generating an S-record or a raw binary file, it may be helpful to
107 use -S to remove sections containing debugging information. In some
108 cases -R will be useful to remove sections which contain information
109 that is not needed by the binary file.
110 Note---objcopy is not able to change the endianness of its input files.
112 If the input format has an endianness (some formats do not), objcopy
113 can only copy the inputs into file formats that have the same
114 endianness or which have no endianness (e.g., srec). (However, see the
115 --reverse-bytes option.)
116
118 infile
119 outfile
120 The input and output files, respectively. If you do not specify
121 outfile, objcopy creates a temporary file and destructively renames
122 the result with the name of infile.
123 -I bfdname
125 --input-target=bfdname
126 Consider the source file's object format to be bfdname, rather than
127 attempting to deduce it.
128 -O bfdname
130 --output-target=bfdname
131 Write the output file using the object format bfdname.
132 -F bfdname
134 --target=bfdname
135 Use bfdname as the object format for both the input and the output
136 file; i.e., simply transfer data from source to destination with no
137 translation.
138 -B bfdarch
140 --binary-architecture=bfdarch
141 Useful when transforming a raw binary input file into an object
142 file. In this case the output architecture can be set to bfdarch.
143 This option will be ignored if the input file has a known bfdarch.
144 You can access this binary data inside a program by referencing the
145 special symbols that are created by the conversion process. These
146 symbols are called _binary_objfile_start, _binary_objfile_end and
147 _binary_objfile_size. e.g. you can transform a picture file into
148 an object file and then access it in your code using these symbols.
149 -j sectionname
151 --only-section=sectionname
152 Copy only the named section from the input file to the output file.
153 This option may be given more than once. Note that using this
154 option inappropriately may make the output file unusable.
155 -R sectionname
157 --remove-section=sectionname
158 Remove any section named sectionname from the output file. This
159 option may be given more than once. Note that using this option
160 inappropriately may make the output file unusable.
161 -S
163 --strip-all
164 Do not copy relocation and symbol information from the source file.
165 -g
167 --strip-debug
168 Do not copy debugging symbols or sections from the source file.
169 --strip-unneeded
171 Strip all symbols that are not needed for relocation processing.
172 -K symbolname
174 --keep-symbol=symbolname
175 When stripping symbols, keep symbol symbolname even if it would
176 normally be stripped. This option may be given more than once.
177 -N symbolname
179 --strip-symbol=symbolname
180 Do not copy symbol symbolname from the source file. This option
181 may be given more than once.
182 --strip-unneeded-symbol=symbolname
184 Do not copy symbol symbolname from the source file unless it is
185 needed by a relocation. This option may be given more than once.
186 -G symbolname
188 --keep-global-symbol=symbolname
189 Keep only symbol symbolname global. Make all other symbols local
190 to the file, so that they are not visible externally. This option
191 may be given more than once.
192 --localize-hidden
194 In an ELF object, mark all symbols that have hidden or internal
195 visibility as local. This option applies on top of symbol-specific
196 localization options such as -L.
197 -L symbolname
199 --localize-symbol=symbolname
200 Make symbol symbolname local to the file, so that it is not visible
201 externally. This option may be given more than once.
202 -W symbolname
204 --weaken-symbol=symbolname
205 Make symbol symbolname weak. This option may be given more than
206 once.
207 --globalize-symbol=symbolname
209 Give symbol symbolname global scoping so that it is visible outside
210 of the file in which it is defined. This option may be given more
211 than once.
212 -w
214 --wildcard
215 Permit regular expressions in symbolnames used in other command
216 line options. The question mark (?), asterisk (*), backslash (\)
217 and square brackets ([]) operators can be used anywhere in the
218 symbol name. If the first character of the symbol name is the
219 exclamation point (!) then the sense of the switch is reversed for
220 that symbol. For example:
221 -w -W !foo -W fo*
223 would cause objcopy to weaken all symbols that start with "fo"
225 except for the symbol "foo".
226 -x
228 --discard-all
229 Do not copy non-global symbols from the source file.
230 -X
232 --discard-locals
233 Do not copy compiler-generated local symbols. (These usually start
234 with L or ..)
235 -b byte
237 --byte=byte
238 Keep only every byteth byte of the input file (header data is not
239 affected). byte can be in the range from 0 to interleave-1, where
240 interleave is given by the -i or --interleave option, or the
241 default of 4. This option is useful for creating files to program
242 ROM. It is typically used with an "srec" output target.
243 -i interleave
245 --interleave=interleave
246 Only copy one out of every interleave bytes. Select which byte to
247 copy with the -b or --byte option. The default is 4. objcopy
248 ignores this option if you do not specify either -b or --byte.
249 -p
251 --preserve-dates
252 Set the access and modification dates of the output file to be the
253 same as those of the input file.
254 --debugging
256 Convert debugging information, if possible. This is not the
257 default because only certain debugging formats are supported, and
258 the conversion process can be time consuming.
259 --gap-fill val
261 Fill gaps between sections with val. This operation applies to the
262 load address (LMA) of the sections. It is done by increasing the
263 size of the section with the lower address, and filling in the
264 extra space created with val.
265 --pad-to address
267 Pad the output file up to the load address address. This is done
268 by increasing the size of the last section. The extra space is
269 filled in with the value specified by --gap-fill (default zero).
270 --set-start val
272 Set the start address of the new file to val. Not all object file
273 formats support setting the start address.
274 --change-start incr
276 --adjust-start incr
277 Change the start address by adding incr. Not all object file
278 formats support setting the start address.
279 --change-addresses incr
281 --adjust-vma incr
282 Change the VMA and LMA addresses of all sections, as well as the
283 start address, by adding incr. Some object file formats do not
284 permit section addresses to be changed arbitrarily. Note that this
285 does not relocate the sections; if the program expects sections to
286 be loaded at a certain address, and this option is used to change
287 the sections such that they are loaded at a different address, the
288 program may fail.
289 --change-section-address section{=,+,-}val
291 --adjust-section-vma section{=,+,-}val
292 Set or change both the VMA address and the LMA address of the named
293 section. If = is used, the section address is set to val.
294 Otherwise, val is added to or subtracted from the section address.
295 See the comments under --change-addresses, above. If section does
296 not exist in the input file, a warning will be issued, unless
297 --no-change-warnings is used.
298 --change-section-lma section{=,+,-}val
300 Set or change the LMA address of the named section. The LMA
301 address is the address where the section will be loaded into memory
302 at program load time. Normally this is the same as the VMA
303 address, which is the address of the section at program run time,
304 but on some systems, especially those where a program is held in
305 ROM, the two can be different. If = is used, the section address
306 is set to val. Otherwise, val is added to or subtracted from the
307 section address. See the comments under --change-addresses, above.
308 If section does not exist in the input file, a warning will be
309 issued, unless --no-change-warnings is used.
310 --change-section-vma section{=,+,-}val
312 Set or change the VMA address of the named section. The VMA
313 address is the address where the section will be located once the
314 program has started executing. Normally this is the same as the
315 LMA address, which is the address where the section will be loaded
316 into memory, but on some systems, especially those where a program
317 is held in ROM, the two can be different. If = is used, the
318 section address is set to val. Otherwise, val is added to or
319 subtracted from the section address. See the comments under
320 --change-addresses, above. If section does not exist in the input
321 file, a warning will be issued, unless --no-change-warnings is
322 used.
323 --change-warnings
325 --adjust-warnings
326 If --change-section-address or --change-section-lma or
327 --change-section-vma is used, and the named section does not exist,
328 issue a warning. This is the default.
329 --no-change-warnings
331 --no-adjust-warnings
332 Do not issue a warning if --change-section-address or
333 --adjust-section-lma or --adjust-section-vma is used, even if the
334 named section does not exist.
335 --set-section-flags section=flags
337 Set the flags for the named section. The flags argument is a comma
338 separated string of flag names. The recognized names are alloc,
339 contents, load, noload, readonly, code, data, rom, share, and
340 debug. You can set the contents flag for a section which does not
341 have contents, but it is not meaningful to clear the contents flag
342 of a section which does have contents--just remove the section
343 instead. Not all flags are meaningful for all object file formats.
344 --add-section sectionname=filename
346 Add a new section named sectionname while copying the file. The
347 contents of the new section are taken from the file filename. The
348 size of the section will be the size of the file. This option only
349 works on file formats which can support sections with arbitrary
350 names.
351 --rename-section oldname=newname[,flags]
353 Rename a section from oldname to newname, optionally changing the
354 section's flags to flags in the process. This has the advantage
355 over usng a linker script to perform the rename in that the output
356 stays as an object file and does not become a linked executable.
357 This option is particularly helpful when the input format is
359 binary, since this will always create a section called .data. If
360 for example, you wanted instead to create a section called .rodata
361 containing binary data you could use the following command line to
362 achieve it:
363 objcopy -I binary -O <output_format> -B <architecture> \
365 --rename-section .data=.rodata,alloc,load,readonly,data,contents \
366 <input_binary_file> <output_object_file>
367 --long-section-names {enable,disable,keep}
369 Controls the handling of long section names when processing "COFF"
370 and "PE-COFF" object formats. The default behaviour, keep, is to
371 preserve long section names if any are present in the input file.
372 The enable and disable options forcibly enable or disable the use
373 of long section names in the output object; when disable is in
374 effect, any long section names in the input object will be
375 truncated. The enable option will only emit long section names if
376 any are present in the inputs; this is mostly the same as keep, but
377 it is left undefined whether the enable option might force the
378 creation of an empty string table in the output file.
379 --change-leading-char
381 Some object file formats use special characters at the start of
382 symbols. The most common such character is underscore, which
383 compilers often add before every symbol. This option tells objcopy
384 to change the leading character of every symbol when it converts
385 between object file formats. If the object file formats use the
386 same leading character, this option has no effect. Otherwise, it
387 will add a character, or remove a character, or change a character,
388 as appropriate.
389 --remove-leading-char
391 If the first character of a global symbol is a special symbol
392 leading character used by the object file format, remove the
393 character. The most common symbol leading character is underscore.
394 This option will remove a leading underscore from all global
395 symbols. This can be useful if you want to link together objects
396 of different file formats with different conventions for symbol
397 names. This is different from --change-leading-char because it
398 always changes the symbol name when appropriate, regardless of the
399 object file format of the output file.
400 --reverse-bytes=num
402 Reverse the bytes in a section with output contents. A section
403 length must be evenly divisible by the value given in order for the
404 swap to be able to take place. Reversing takes place before the
405 interleaving is performed.
406 This option is used typically in generating ROM images for
408 problematic target systems. For example, on some target boards,
409 the 32-bit words fetched from 8-bit ROMs are re-assembled in
410 little-endian byte order regardless of the CPU byte order.
411 Depending on the programming model, the endianness of the ROM may
412 need to be modified.
413 Consider a simple file with a section containing the following
415 eight bytes: 12345678.
416 Using --reverse-bytes=2 for the above example, the bytes in the
418 output file would be ordered 21436587.
419 Using --reverse-bytes=4 for the above example, the bytes in the
421 output file would be ordered 43218765.
422 By using --reverse-bytes=2 for the above example, followed by
424 --reverse-bytes=4 on the output file, the bytes in the second
425 output file would be ordered 34127856.
426 --srec-len=ival
428 Meaningful only for srec output. Set the maximum length of the
429 Srecords being produced to ival. This length covers both address,
430 data and crc fields.
431 --srec-forceS3
433 Meaningful only for srec output. Avoid generation of S1/S2
434 records, creating S3-only record format.
435 --redefine-sym old=new
437 Change the name of a symbol old, to new. This can be useful when
438 one is trying link two things together for which you have no
439 source, and there are name collisions.
440 --redefine-syms=filename
442 Apply --redefine-sym to each symbol pair "old new" listed in the
443 file filename. filename is simply a flat file, with one symbol
444 pair per line. Line comments may be introduced by the hash
445 character. This option may be given more than once.
446 --weaken
448 Change all global symbols in the file to be weak. This can be
449 useful when building an object which will be linked against other
450 objects using the -R option to the linker. This option is only
451 effective when using an object file format which supports weak
452 symbols.
453 --keep-symbols=filename
455 Apply --keep-symbol option to each symbol listed in the file
456 filename. filename is simply a flat file, with one symbol name per
457 line. Line comments may be introduced by the hash character. This
458 option may be given more than once.
459 --strip-symbols=filename
461 Apply --strip-symbol option to each symbol listed in the file
462 filename. filename is simply a flat file, with one symbol name per
463 line. Line comments may be introduced by the hash character. This
464 option may be given more than once.
465 --strip-unneeded-symbols=filename
467 Apply --strip-unneeded-symbol option to each symbol listed in the
468 file filename. filename is simply a flat file, with one symbol
469 name per line. Line comments may be introduced by the hash
470 character. This option may be given more than once.
471 --keep-global-symbols=filename
473 Apply --keep-global-symbol option to each symbol listed in the file
474 filename. filename is simply a flat file, with one symbol name per
475 line. Line comments may be introduced by the hash character. This
476 option may be given more than once.
477 --localize-symbols=filename
479 Apply --localize-symbol option to each symbol listed in the file
480 filename. filename is simply a flat file, with one symbol name per
481 line. Line comments may be introduced by the hash character. This
482 option may be given more than once.
483 --globalize-symbols=filename
485 Apply --globalize-symbol option to each symbol listed in the file
486 filename. filename is simply a flat file, with one symbol name per
487 line. Line comments may be introduced by the hash character. This
488 option may be given more than once.
489 --weaken-symbols=filename
491 Apply --weaken-symbol option to each symbol listed in the file
492 filename. filename is simply a flat file, with one symbol name per
493 line. Line comments may be introduced by the hash character. This
494 option may be given more than once.
495 --alt-machine-code=index
497 If the output architecture has alternate machine codes, use the
498 indexth code instead of the default one. This is useful in case a
499 machine is assigned an official code and the tool-chain adopts the
500 new code, but other applications still depend on the original code
501 being used. For ELF based architectures if the index alternative
502 does not exist then the value is treated as an absolute number to
503 be stored in the e_machine field of the ELF header.
504 --writable-text
506 Mark the output text as writable. This option isn't meaningful for
507 all object file formats.
508 --readonly-text
510 Make the output text write protected. This option isn't meaningful
511 for all object file formats.
512 --pure
514 Mark the output file as demand paged. This option isn't meaningful
515 for all object file formats.
516 --impure
518 Mark the output file as impure. This option isn't meaningful for
519 all object file formats.
520 --prefix-symbols=string
522 Prefix all symbols in the output file with string.
523 --prefix-sections=string
525 Prefix all section names in the output file with string.
526 --prefix-alloc-sections=string
528 Prefix all the names of all allocated sections in the output file
529 with string.
530 --add-gnu-debuglink=path-to-file
532 Creates a .gnu_debuglink section which contains a reference to
533 path-to-file and adds it to the output file.
534 --keep-file-symbols
536 When stripping a file, perhaps with --strip-debug or
537 --strip-unneeded, retain any symbols specifying source file names,
538 which would otherwise get stripped.
539 --only-keep-debug
541 Strip a file, removing contents of any sections that would not be
542 stripped by --strip-debug and leaving the debugging sections
543 intact. In ELF files, this preserves all note sections in the
544 output.
545 The intention is that this option will be used in conjunction with
547 --add-gnu-debuglink to create a two part executable. One a
548 stripped binary which will occupy less space in RAM and in a
549 distribution and the second a debugging information file which is
550 only needed if debugging abilities are required. The suggested
551 procedure to create these files is as follows:
552 1.<Link the executable as normal. Assuming that is is called>
554 "foo" then...
555 1.<Run "objcopy --only-keep-debug foo foo.dbg" to>
557 create a file containing the debugging info.
558 1.<Run "objcopy --strip-debug foo" to create a>
560 stripped executable.
561 1.<Run "objcopy --add-gnu-debuglink=foo.dbg foo">
563 to add a link to the debugging info into the stripped
564 executable.
565 Note---the choice of ".dbg" as an extension for the debug info file
567 is arbitrary. Also the "--only-keep-debug" step is optional. You
568 could instead do this:
569 1.<Link the executable as normal.>
571 1.<Copy "foo" to "foo.full">
572 1.<Run "objcopy --strip-debug foo">
573 1.<Run "objcopy --add-gnu-debuglink=foo.full foo">
574 i.e., the file pointed to by the --add-gnu-debuglink can be the
576 full executable. It does not have to be a file created by the
577 --only-keep-debug switch.
578 Note---this switch is only intended for use on fully linked files.
580 It does not make sense to use it on object files where the
581 debugging information may be incomplete. Besides the gnu_debuglink
582 feature currently only supports the presence of one filename
583 containing debugging information, not multiple filenames on a one-
584 per-object-file basis.
585 --file-alignment num
587 Specify the file alignment. Sections in the file will always begin
588 at file offsets which are multiples of this number. This defaults
589 to 512. [This option is specific to PE targets.]
590 --heap reserve
592 --heap reserve,commit
593 Specify the number of bytes of memory to reserve (and optionally
594 commit) to be used as heap for this program. [This option is
595 specific to PE targets.]
596 --image-base value
598 Use value as the base address of your program or dll. This is the
599 lowest memory location that will be used when your program or dll
600 is loaded. To reduce the need to relocate and improve performance
601 of your dlls, each should have a unique base address and not
602 overlap any other dlls. The default is 0x400000 for executables,
603 and 0x10000000 for dlls. [This option is specific to PE targets.]
604 --section-alignment num
606 Sets the section alignment. Sections in memory will always begin
607 at addresses which are a multiple of this number. Defaults to
608 0x1000. [This option is specific to PE targets.]
609 --stack reserve
611 --stack reserve,commit
612 Specify the number of bytes of memory to reserve (and optionally
613 commit) to be used as stack for this program. [This option is
614 specific to PE targets.]
615 --subsystem which
617 --subsystem which:major
618 --subsystem which:major.minor
619 Specifies the subsystem under which your program will execute. The
620 legal values for which are "native", "windows", "console", "posix",
621 "efi-app", "efi-bsd", "efi-rtd", "sal-rtd", and "xbox". You may
622 optionally set the subsystem version also. Numeric values are also
623 accepted for which. [This option is specific to PE targets.]
624 --extract-symbol
626 Keep the file's section flags and symbols but remove all section
627 data. Specifically, the option:
628 *<removes the contents of all sections;>
630 *<sets the size of every section to zero; and>
631 *<sets the file's start address to zero.>
632 This option is used to build a .sym file for a VxWorks kernel. It
634 can also be a useful way of reducing the size of a --just-symbols
635 linker input file.
636 -V
638 --version
639 Show the version number of objcopy.
640 -v
642 --verbose
643 Verbose output: list all object files modified. In the case of
644 archives, objcopy -V lists all members of the archive.
645 --help
647 Show a summary of the options to objcopy.
648 --info
650 Display a list showing all architectures and object formats
651 available.
652 @file
654 Read command-line options from file. The options read are inserted
655 in place of the original @file option. If file does not exist, or
656 cannot be read, then the option will be treated literally, and not
657 removed.
658 Options in file are separated by whitespace. A whitespace
660 character may be included in an option by surrounding the entire
661 option in either single or double quotes. Any character (including
662 a backslash) may be included by prefixing the character to be
663 included with a backslash. The file may itself contain additional
664 @file options; any such options will be processed recursively.
665
667 ld(1), objdump(1), and the Info entries for binutils.
668
670 Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
671 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free
672 Software Foundation, Inc.
673 Permission is granted to copy, distribute and/or modify this document
675 under the terms of the GNU Free Documentation License, Version 1.3 or
676 any later version published by the Free Software Foundation; with no
677 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
678 Texts. A copy of the license is included in the section entitled "GNU
679 Free Documentation License".
680binutils-2.20 2009-10-16 OBJCOPY(1)