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 [--strip-unneeded]
16 [-K symbolname|--keep-symbol=symbolname]
17 [--keep-file-symbols]
18 [--keep-section-symbols]
19 [-N symbolname|--strip-symbol=symbolname]
20 [--strip-unneeded-symbol=symbolname]
21 [-G symbolname|--keep-global-symbol=symbolname]
22 [--localize-hidden]
23 [-L symbolname|--localize-symbol=symbolname]
24 [--globalize-symbol=symbolname]
25 [--globalize-symbols=filename]
26 [-W symbolname|--weaken-symbol=symbolname]
27 [-w|--wildcard]
28 [-x|--discard-all]
29 [-X|--discard-locals]
30 [-b byte|--byte=byte]
31 [-i [breadth]|--interleave[=breadth]]
32 [--interleave-width=width]
33 [-j sectionpattern|--only-section=sectionpattern]
34 [-R sectionpattern|--remove-section=sectionpattern]
35 [--keep-section=sectionpattern]
36 [--remove-relocations=sectionpattern]
37 [-p|--preserve-dates]
38 [-D|--enable-deterministic-archives]
39 [-U|--disable-deterministic-archives]
40 [--debugging]
41 [--gap-fill=val]
42 [--pad-to=address]
43 [--set-start=val]
44 [--adjust-start=incr]
45 [--change-addresses=incr]
46 [--change-section-address sectionpattern{=,+,-}val]
47 [--change-section-lma sectionpattern{=,+,-}val]
48 [--change-section-vma sectionpattern{=,+,-}val]
49 [--change-warnings] [--no-change-warnings]
50 [--set-section-flags sectionpattern=flags]
51 [--set-section-alignment sectionpattern=align]
52 [--add-section sectionname=filename]
53 [--dump-section sectionname=filename]
54 [--update-section sectionname=filename]
55 [--rename-section oldname=newname[,flags]]
56 [--long-section-names {enable,disable,keep}]
57 [--change-leading-char] [--remove-leading-char]
58 [--reverse-bytes=num]
59 [--srec-len=ival] [--srec-forceS3]
60 [--redefine-sym old=new]
61 [--redefine-syms=filename]
62 [--weaken]
63 [--keep-symbols=filename]
64 [--strip-symbols=filename]
65 [--strip-unneeded-symbols=filename]
66 [--keep-global-symbols=filename]
67 [--localize-symbols=filename]
68 [--weaken-symbols=filename]
69 [--add-symbol name=[section:]value[,flags]]
70 [--alt-machine-code=index]
71 [--prefix-symbols=string]
72 [--prefix-sections=string]
73 [--prefix-alloc-sections=string]
74 [--add-gnu-debuglink=path-to-file]
75 [--only-keep-debug]
76 [--strip-dwo]
77 [--extract-dwo]
78 [--extract-symbol]
79 [--writable-text]
80 [--readonly-text]
81 [--pure]
82 [--impure]
83 [--file-alignment=num]
84 [--heap=size]
85 [--image-base=address]
86 [--section-alignment=num]
87 [--stack=size]
88 [--subsystem=which:major.minor]
89 [--compress-debug-sections]
90 [--decompress-debug-sections]
91 [--elf-stt-common=val]
92 [--merge-notes]
93 [--no-merge-notes]
94 [--verilog-data-width=val]
95 [-v|--verbose]
96 [-V|--version]
97 [--help] [--info]
98 infile [outfile]
99
101 The GNU objcopy utility copies the contents of an object file to
102 another. objcopy uses the GNU BFD Library to read and write the object
103 files. It can write the destination object file in a format different
104 from that of the source object file. The exact behavior of objcopy is
105 controlled by command-line options. Note that objcopy should be able
106 to copy a fully linked file between any two formats. However, copying a
107 relocatable object file between any two formats may not work as
108 expected.
109 objcopy creates temporary files to do its translations and deletes them
111 afterward. objcopy uses BFD to do all its translation work; it has
112 access to all the formats described in BFD and thus is able to
113 recognize most formats without being told explicitly.
114 objcopy can be used to generate S-records by using an output target of
116 srec (e.g., use -O srec).
117 objcopy can be used to generate a raw binary file by using an output
119 target of binary (e.g., use -O binary). When objcopy generates a raw
120 binary file, it will essentially produce a memory dump of the contents
121 of the input object file. All symbols and relocation information will
122 be discarded. The memory dump will start at the load address of the
123 lowest section copied into the output file.
124 When generating an S-record or a raw binary file, it may be helpful to
126 use -S to remove sections containing debugging information. In some
127 cases -R will be useful to remove sections which contain information
128 that is not needed by the binary file.
129 Note---objcopy is not able to change the endianness of its input files.
131 If the input format has an endianness (some formats do not), objcopy
132 can only copy the inputs into file formats that have the same
133 endianness or which have no endianness (e.g., srec). (However, see the
134 --reverse-bytes option.)
135
137 infile
138 outfile
139 The input and output files, respectively. If you do not specify
140 outfile, objcopy creates a temporary file and destructively renames
141 the result with the name of infile.
142 -I bfdname
144 --input-target=bfdname
145 Consider the source file's object format to be bfdname, rather than
146 attempting to deduce it.
147 -O bfdname
149 --output-target=bfdname
150 Write the output file using the object format bfdname.
151 -F bfdname
153 --target=bfdname
154 Use bfdname as the object format for both the input and the output
155 file; i.e., simply transfer data from source to destination with no
156 translation.
157 -B bfdarch
159 --binary-architecture=bfdarch
160 Useful when transforming a architecture-less input file into an
161 object file. In this case the output architecture can be set to
162 bfdarch. This option will be ignored if the input file has a known
163 bfdarch. You can access this binary data inside a program by
164 referencing the special symbols that are created by the conversion
165 process. These symbols are called _binary_objfile_start,
166 _binary_objfile_end and _binary_objfile_size. e.g. you can
167 transform a picture file into an object file and then access it in
168 your code using these symbols.
169 -j sectionpattern
171 --only-section=sectionpattern
172 Copy only the indicated sections from the input file to the output
173 file. This option may be given more than once. Note that using
174 this option inappropriately may make the output file unusable.
175 Wildcard characters are accepted in sectionpattern.
176 If the first character of sectionpattern is the exclamation point
178 (!) then matching sections will not be copied, even if earlier use
179 of --only-section on the same command line would otherwise copy it.
180 For example:
181 --only-section=.text.* --only-section=!.text.foo
183 will copy all sectinos matching '.text.*' but not the section
185 '.text.foo'.
186 -R sectionpattern
188 --remove-section=sectionpattern
189 Remove any section matching sectionpattern from the output file.
190 This option may be given more than once. Note that using this
191 option inappropriately may make the output file unusable. Wildcard
192 characters are accepted in sectionpattern. Using both the -j and
193 -R options together results in undefined behaviour.
194 If the first character of sectionpattern is the exclamation point
196 (!) then matching sections will not be removed even if an earlier
197 use of --remove-section on the same command line would otherwise
198 remove it. For example:
199 --remove-section=.text.* --remove-section=!.text.foo
201 will remove all sections matching the pattern '.text.*', but will
203 not remove the section '.text.foo'.
204 --keep-section=sectionpattern
206 When removing sections from the output file, keep sections that
207 match sectionpattern.
208 --remove-relocations=sectionpattern
210 Remove non-dynamic relocations from the output file for any section
211 matching sectionpattern. This option may be given more than once.
212 Note that using this option inappropriately may make the output
213 file unusable, and attempting to remove a dynamic relocation
214 section such as .rela.plt from an executable or shared library with
215 --remove-relocations=.plt will not work. Wildcard characters are
216 accepted in sectionpattern. For example:
217 --remove-relocations=.text.*
219 will remove the relocations for all sections matching the pattern
221 '.text.*'.
222 If the first character of sectionpattern is the exclamation point
224 (!) then matching sections will not have their relocation removed
225 even if an earlier use of --remove-relocations on the same command
226 line would otherwise cause the relocations to be removed. For
227 example:
228 --remove-relocations=.text.* --remove-relocations=!.text.foo
230 will remove all relocations for sections matching the pattern
232 '.text.*', but will not remove relocations for the section
233 '.text.foo'.
234 -S
236 --strip-all
237 Do not copy relocation and symbol information from the source file.
238 Also deletes debug sections.
239 -g
241 --strip-debug
242 Do not copy debugging symbols or sections from the source file.
243 --strip-unneeded
245 Remove all symbols that are not needed for relocation processing in
246 addition to debugging symbols and sections stripped by
247 --strip-debug.
248 -K symbolname
250 --keep-symbol=symbolname
251 When stripping symbols, keep symbol symbolname even if it would
252 normally be stripped. This option may be given more than once.
253 -N symbolname
255 --strip-symbol=symbolname
256 Do not copy symbol symbolname from the source file. This option
257 may be given more than once.
258 --strip-unneeded-symbol=symbolname
260 Do not copy symbol symbolname from the source file unless it is
261 needed by a relocation. This option may be given more than once.
262 -G symbolname
264 --keep-global-symbol=symbolname
265 Keep only symbol symbolname global. Make all other symbols local
266 to the file, so that they are not visible externally. This option
267 may be given more than once. Note: this option cannot be used in
268 conjunction with the --globalize-symbol or --globalize-symbols
269 options.
270 --localize-hidden
272 In an ELF object, mark all symbols that have hidden or internal
273 visibility as local. This option applies on top of symbol-specific
274 localization options such as -L.
275 -L symbolname
277 --localize-symbol=symbolname
278 Convert a global or weak symbol called symbolname into a local
279 symbol, so that it is not visible externally. This option may be
280 given more than once. Note - unique symbols are not converted.
281 -W symbolname
283 --weaken-symbol=symbolname
284 Make symbol symbolname weak. This option may be given more than
285 once.
286 --globalize-symbol=symbolname
288 Give symbol symbolname global scoping so that it is visible outside
289 of the file in which it is defined. This option may be given more
290 than once. Note: this option cannot be used in conjunction with
291 the -G or --keep-global-symbol options.
292 -w
294 --wildcard
295 Permit regular expressions in symbolnames used in other command
296 line options. The question mark (?), asterisk (*), backslash (\)
297 and square brackets ([]) operators can be used anywhere in the
298 symbol name. If the first character of the symbol name is the
299 exclamation point (!) then the sense of the switch is reversed for
300 that symbol. For example:
301 -w -W !foo -W fo*
303 would cause objcopy to weaken all symbols that start with "fo"
305 except for the symbol "foo".
306 -x
308 --discard-all
309 Do not copy non-global symbols from the source file.
310 -X
312 --discard-locals
313 Do not copy compiler-generated local symbols. (These usually start
314 with L or ..)
315 -b byte
317 --byte=byte
318 If interleaving has been enabled via the --interleave option then
319 start the range of bytes to keep at the byteth byte. byte can be
320 in the range from 0 to breadth-1, where breadth is the value given
321 by the --interleave option.
322 -i [breadth]
324 --interleave[=breadth]
325 Only copy a range out of every breadth bytes. (Header data is not
326 affected). Select which byte in the range begins the copy with the
327 --byte option. Select the width of the range with the
328 --interleave-width option.
329 This option is useful for creating files to program ROM. It is
331 typically used with an "srec" output target. Note that objcopy
332 will complain if you do not specify the --byte option as well.
333 The default interleave breadth is 4, so with --byte set to 0,
335 objcopy would copy the first byte out of every four bytes from the
336 input to the output.
337 --interleave-width=width
339 When used with the --interleave option, copy width bytes at a time.
340 The start of the range of bytes to be copied is set by the --byte
341 option, and the extent of the range is set with the --interleave
342 option.
343 The default value for this option is 1. The value of width plus
345 the byte value set by the --byte option must not exceed the
346 interleave breadth set by the --interleave option.
347 This option can be used to create images for two 16-bit flashes
349 interleaved in a 32-bit bus by passing -b 0 -i 4
350 --interleave-width=2 and -b 2 -i 4 --interleave-width=2 to two
351 objcopy commands. If the input was '12345678' then the outputs
352 would be '1256' and '3478' respectively.
353 -p
355 --preserve-dates
356 Set the access and modification dates of the output file to be the
357 same as those of the input file.
358 -D
360 --enable-deterministic-archives
361 Operate in deterministic mode. When copying archive members and
362 writing the archive index, use zero for UIDs, GIDs, timestamps, and
363 use consistent file modes for all files.
364 If binutils was configured with --enable-deterministic-archives,
366 then this mode is on by default. It can be disabled with the -U
367 option, below.
368 -U
370 --disable-deterministic-archives
371 Do not operate in deterministic mode. This is the inverse of the
372 -D option, above: when copying archive members and writing the
373 archive index, use their actual UID, GID, timestamp, and file mode
374 values.
375 This is the default unless binutils was configured with
377 --enable-deterministic-archives.
378 --debugging
380 Convert debugging information, if possible. This is not the
381 default because only certain debugging formats are supported, and
382 the conversion process can be time consuming.
383 --gap-fill val
385 Fill gaps between sections with val. This operation applies to the
386 load address (LMA) of the sections. It is done by increasing the
387 size of the section with the lower address, and filling in the
388 extra space created with val.
389 --pad-to address
391 Pad the output file up to the load address address. This is done
392 by increasing the size of the last section. The extra space is
393 filled in with the value specified by --gap-fill (default zero).
394 --set-start val
396 Set the start address (also known as the entry address) of the new
397 file to val. Not all object file formats support setting the start
398 address.
399 --change-start incr
401 --adjust-start incr
402 Change the start address (also known as the entry address) by
403 adding incr. Not all object file formats support setting the start
404 address.
405 --change-addresses incr
407 --adjust-vma incr
408 Change the VMA and LMA addresses of all sections, as well as the
409 start address, by adding incr. Some object file formats do not
410 permit section addresses to be changed arbitrarily. Note that this
411 does not relocate the sections; if the program expects sections to
412 be loaded at a certain address, and this option is used to change
413 the sections such that they are loaded at a different address, the
414 program may fail.
415 --change-section-address sectionpattern{=,+,-}val
417 --adjust-section-vma sectionpattern{=,+,-}val
418 Set or change both the VMA address and the LMA address of any
419 section matching sectionpattern. If = is used, the section address
420 is set to val. Otherwise, val is added to or subtracted from the
421 section address. See the comments under --change-addresses, above.
422 If sectionpattern does not match any sections in the input file, a
423 warning will be issued, unless --no-change-warnings is used.
424 --change-section-lma sectionpattern{=,+,-}val
426 Set or change the LMA address of any sections matching
427 sectionpattern. The LMA address is the address where the section
428 will be loaded into memory at program load time. Normally this is
429 the same as the VMA address, which is the address of the section at
430 program run time, but on some systems, especially those where a
431 program is held in ROM, the two can be different. If = is used,
432 the section address is set to val. Otherwise, val is added to or
433 subtracted from the section address. See the comments under
434 --change-addresses, above. If sectionpattern does not match any
435 sections in the input file, a warning will be issued, unless
436 --no-change-warnings is used.
437 --change-section-vma sectionpattern{=,+,-}val
439 Set or change the VMA address of any section matching
440 sectionpattern. The VMA address is the address where the section
441 will be located once the program has started executing. Normally
442 this is the same as the LMA address, which is the address where the
443 section will be loaded into memory, but on some systems, especially
444 those where a program is held in ROM, the two can be different. If
445 = is used, the section address is set to val. Otherwise, val is
446 added to or subtracted from the section address. See the comments
447 under --change-addresses, above. If sectionpattern does not match
448 any sections in the input file, a warning will be issued, unless
449 --no-change-warnings is used.
450 --change-warnings
452 --adjust-warnings
453 If --change-section-address or --change-section-lma or
454 --change-section-vma is used, and the section pattern does not
455 match any sections, issue a warning. This is the default.
456 --no-change-warnings
458 --no-adjust-warnings
459 Do not issue a warning if --change-section-address or
460 --adjust-section-lma or --adjust-section-vma is used, even if the
461 section pattern does not match any sections.
462 --set-section-flags sectionpattern=flags
464 Set the flags for any sections matching sectionpattern. The flags
465 argument is a comma separated string of flag names. The recognized
466 names are alloc, contents, load, noload, readonly, code, data, rom,
467 exclude, share, and debug. You can set the contents flag for a
468 section which does not have contents, but it is not meaningful to
469 clear the contents flag of a section which does have contents--just
470 remove the section instead. Not all flags are meaningful for all
471 object file formats. In particular the share flag is only
472 meaningful for COFF format files and not for ELF format files.
473 --set-section-alignment sectionpattern=align
475 Set the alignment for any sections matching sectionpattern. align
476 specifies the alignment in bytes and must be a power of two, i.e.
477 1, 2, 4, 8....
478 --add-section sectionname=filename
480 Add a new section named sectionname while copying the file. The
481 contents of the new section are taken from the file filename. The
482 size of the section will be the size of the file. This option only
483 works on file formats which can support sections with arbitrary
484 names. Note - it may be necessary to use the --set-section-flags
485 option to set the attributes of the newly created section.
486 --dump-section sectionname=filename
488 Place the contents of section named sectionname into the file
489 filename, overwriting any contents that may have been there
490 previously. This option is the inverse of --add-section. This
491 option is similar to the --only-section option except that it does
492 not create a formatted file, it just dumps the contents as raw
493 binary data, without applying any relocations. The option can be
494 specified more than once.
495 --update-section sectionname=filename
497 Replace the existing contents of a section named sectionname with
498 the contents of file filename. The size of the section will be
499 adjusted to the size of the file. The section flags for
500 sectionname will be unchanged. For ELF format files the section to
501 segment mapping will also remain unchanged, something which is not
502 possible using --remove-section followed by --add-section. The
503 option can be specified more than once.
504 Note - it is possible to use --rename-section and --update-section
506 to both update and rename a section from one command line. In this
507 case, pass the original section name to --update-section, and the
508 original and new section names to --rename-section.
509 --add-symbol name=[section:]value[,flags]
511 Add a new symbol named name while copying the file. This option
512 may be specified multiple times. If the section is given, the
513 symbol will be associated with and relative to that section,
514 otherwise it will be an ABS symbol. Specifying an undefined
515 section will result in a fatal error. There is no check for the
516 value, it will be taken as specified. Symbol flags can be
517 specified and not all flags will be meaningful for all object file
518 formats. By default, the symbol will be global. The special flag
519 'before=othersym' will insert the new symbol in front of the
520 specified othersym, otherwise the symbol(s) will be added at the
521 end of the symbol table in the order they appear.
522 --rename-section oldname=newname[,flags]
524 Rename a section from oldname to newname, optionally changing the
525 section's flags to flags in the process. This has the advantage
526 over using a linker script to perform the rename in that the output
527 stays as an object file and does not become a linked executable.
528 This option accepts the same set of flags as the
529 --sect-section-flags option.
530 This option is particularly helpful when the input format is
532 binary, since this will always create a section called .data. If
533 for example, you wanted instead to create a section called .rodata
534 containing binary data you could use the following command line to
535 achieve it:
536 objcopy -I binary -O <output_format> -B <architecture> \
538 --rename-section .data=.rodata,alloc,load,readonly,data,contents \
539 <input_binary_file> <output_object_file>
540 --long-section-names {enable,disable,keep}
542 Controls the handling of long section names when processing "COFF"
543 and "PE-COFF" object formats. The default behaviour, keep, is to
544 preserve long section names if any are present in the input file.
545 The enable and disable options forcibly enable or disable the use
546 of long section names in the output object; when disable is in
547 effect, any long section names in the input object will be
548 truncated. The enable option will only emit long section names if
549 any are present in the inputs; this is mostly the same as keep, but
550 it is left undefined whether the enable option might force the
551 creation of an empty string table in the output file.
552 --change-leading-char
554 Some object file formats use special characters at the start of
555 symbols. The most common such character is underscore, which
556 compilers often add before every symbol. This option tells objcopy
557 to change the leading character of every symbol when it converts
558 between object file formats. If the object file formats use the
559 same leading character, this option has no effect. Otherwise, it
560 will add a character, or remove a character, or change a character,
561 as appropriate.
562 --remove-leading-char
564 If the first character of a global symbol is a special symbol
565 leading character used by the object file format, remove the
566 character. The most common symbol leading character is underscore.
567 This option will remove a leading underscore from all global
568 symbols. This can be useful if you want to link together objects
569 of different file formats with different conventions for symbol
570 names. This is different from --change-leading-char because it
571 always changes the symbol name when appropriate, regardless of the
572 object file format of the output file.
573 --reverse-bytes=num
575 Reverse the bytes in a section with output contents. A section
576 length must be evenly divisible by the value given in order for the
577 swap to be able to take place. Reversing takes place before the
578 interleaving is performed.
579 This option is used typically in generating ROM images for
581 problematic target systems. For example, on some target boards,
582 the 32-bit words fetched from 8-bit ROMs are re-assembled in
583 little-endian byte order regardless of the CPU byte order.
584 Depending on the programming model, the endianness of the ROM may
585 need to be modified.
586 Consider a simple file with a section containing the following
588 eight bytes: 12345678.
589 Using --reverse-bytes=2 for the above example, the bytes in the
591 output file would be ordered 21436587.
592 Using --reverse-bytes=4 for the above example, the bytes in the
594 output file would be ordered 43218765.
595 By using --reverse-bytes=2 for the above example, followed by
597 --reverse-bytes=4 on the output file, the bytes in the second
598 output file would be ordered 34127856.
599 --srec-len=ival
601 Meaningful only for srec output. Set the maximum length of the
602 Srecords being produced to ival. This length covers both address,
603 data and crc fields.
604 --srec-forceS3
606 Meaningful only for srec output. Avoid generation of S1/S2
607 records, creating S3-only record format.
608 --redefine-sym old=new
610 Change the name of a symbol old, to new. This can be useful when
611 one is trying link two things together for which you have no
612 source, and there are name collisions.
613 --redefine-syms=filename
615 Apply --redefine-sym to each symbol pair "old new" listed in the
616 file filename. filename is simply a flat file, with one symbol
617 pair per line. Line comments may be introduced by the hash
618 character. This option may be given more than once.
619 --weaken
621 Change all global symbols in the file to be weak. This can be
622 useful when building an object which will be linked against other
623 objects using the -R option to the linker. This option is only
624 effective when using an object file format which supports weak
625 symbols.
626 --keep-symbols=filename
628 Apply --keep-symbol option to each symbol listed in the file
629 filename. filename is simply a flat file, with one symbol name per
630 line. Line comments may be introduced by the hash character. This
631 option may be given more than once.
632 --strip-symbols=filename
634 Apply --strip-symbol option to each symbol listed in the file
635 filename. filename is simply a flat file, with one symbol name per
636 line. Line comments may be introduced by the hash character. This
637 option may be given more than once.
638 --strip-unneeded-symbols=filename
640 Apply --strip-unneeded-symbol option to each symbol listed in the
641 file filename. filename is simply a flat file, with one symbol
642 name per line. Line comments may be introduced by the hash
643 character. This option may be given more than once.
644 --keep-global-symbols=filename
646 Apply --keep-global-symbol option to each symbol listed in the file
647 filename. filename is simply a flat file, with one symbol name per
648 line. Line comments may be introduced by the hash character. This
649 option may be given more than once.
650 --localize-symbols=filename
652 Apply --localize-symbol option to each symbol listed in the file
653 filename. filename is simply a flat file, with one symbol name per
654 line. Line comments may be introduced by the hash character. This
655 option may be given more than once.
656 --globalize-symbols=filename
658 Apply --globalize-symbol option to each symbol listed in the file
659 filename. filename is simply a flat file, with one symbol name per
660 line. Line comments may be introduced by the hash character. This
661 option may be given more than once. Note: this option cannot be
662 used in conjunction with the -G or --keep-global-symbol options.
663 --weaken-symbols=filename
665 Apply --weaken-symbol option to each symbol listed in the file
666 filename. filename is simply a flat file, with one symbol name per
667 line. Line comments may be introduced by the hash character. This
668 option may be given more than once.
669 --alt-machine-code=index
671 If the output architecture has alternate machine codes, use the
672 indexth code instead of the default one. This is useful in case a
673 machine is assigned an official code and the tool-chain adopts the
674 new code, but other applications still depend on the original code
675 being used. For ELF based architectures if the index alternative
676 does not exist then the value is treated as an absolute number to
677 be stored in the e_machine field of the ELF header.
678 --writable-text
680 Mark the output text as writable. This option isn't meaningful for
681 all object file formats.
682 --readonly-text
684 Make the output text write protected. This option isn't meaningful
685 for all object file formats.
686 --pure
688 Mark the output file as demand paged. This option isn't meaningful
689 for all object file formats.
690 --impure
692 Mark the output file as impure. This option isn't meaningful for
693 all object file formats.
694 --prefix-symbols=string
696 Prefix all symbols in the output file with string.
697 --prefix-sections=string
699 Prefix all section names in the output file with string.
700 --prefix-alloc-sections=string
702 Prefix all the names of all allocated sections in the output file
703 with string.
704 --add-gnu-debuglink=path-to-file
706 Creates a .gnu_debuglink section which contains a reference to
707 path-to-file and adds it to the output file. Note: the file at
708 path-to-file must exist. Part of the process of adding the
709 .gnu_debuglink section involves embedding a checksum of the
710 contents of the debug info file into the section.
711 If the debug info file is built in one location but it is going to
713 be installed at a later time into a different location then do not
714 use the path to the installed location. The --add-gnu-debuglink
715 option will fail because the installed file does not exist yet.
716 Instead put the debug info file in the current directory and use
717 the --add-gnu-debuglink option without any directory components,
718 like this:
719 objcopy --add-gnu-debuglink=foo.debug
721 At debug time the debugger will attempt to look for the separate
723 debug info file in a set of known locations. The exact set of
724 these locations varies depending upon the distribution being used,
725 but it typically includes:
726 "* The same directory as the executable."
728 "* A sub-directory of the directory containing the executable"
729 called .debug
730 "* A global debug directory such as /usr/lib/debug."
732 As long as the debug info file has been installed into one of these
734 locations before the debugger is run everything should work
735 correctly.
736 --keep-section-symbils
738 When stripping a file, perhaps with --strip-debug or
739 --strip-unneeded, retain any symbols specifying section names,
740 which would otherwise get stripped.
741 --keep-file-symbols
743 When stripping a file, perhaps with --strip-debug or
744 --strip-unneeded, retain any symbols specifying source file names,
745 which would otherwise get stripped.
746 --only-keep-debug
748 Strip a file, removing contents of any sections that would not be
749 stripped by --strip-debug and leaving the debugging sections
750 intact. In ELF files, this preserves all note sections in the
751 output.
752 Note - the section headers of the stripped sections are preserved,
754 including their sizes, but the contents of the section are
755 discarded. The section headers are preserved so that other tools
756 can match up the debuginfo file with the real executable, even if
757 that executable has been relocated to a different address space.
758 The intention is that this option will be used in conjunction with
760 --add-gnu-debuglink to create a two part executable. One a
761 stripped binary which will occupy less space in RAM and in a
762 distribution and the second a debugging information file which is
763 only needed if debugging abilities are required. The suggested
764 procedure to create these files is as follows:
765 1.<Link the executable as normal. Assuming that it is called>
767 "foo" then...
768 1.<Run "objcopy --only-keep-debug foo foo.dbg" to>
770 create a file containing the debugging info.
771 1.<Run "objcopy --strip-debug foo" to create a>
773 stripped executable.
774 1.<Run "objcopy --add-gnu-debuglink=foo.dbg foo">
776 to add a link to the debugging info into the stripped
777 executable.
778 Note---the choice of ".dbg" as an extension for the debug info file
780 is arbitrary. Also the "--only-keep-debug" step is optional. You
781 could instead do this:
782 1.<Link the executable as normal.>
784 1.<Copy "foo" to "foo.full">
785 1.<Run "objcopy --strip-debug foo">
786 1.<Run "objcopy --add-gnu-debuglink=foo.full foo">
787 i.e., the file pointed to by the --add-gnu-debuglink can be the
789 full executable. It does not have to be a file created by the
790 --only-keep-debug switch.
791 Note---this switch is only intended for use on fully linked files.
793 It does not make sense to use it on object files where the
794 debugging information may be incomplete. Besides the gnu_debuglink
795 feature currently only supports the presence of one filename
796 containing debugging information, not multiple filenames on a one-
797 per-object-file basis.
798 --strip-dwo
800 Remove the contents of all DWARF .dwo sections, leaving the
801 remaining debugging sections and all symbols intact. This option
802 is intended for use by the compiler as part of the -gsplit-dwarf
803 option, which splits debug information between the .o file and a
804 separate .dwo file. The compiler generates all debug information
805 in the same file, then uses the --extract-dwo option to copy the
806 .dwo sections to the .dwo file, then the --strip-dwo option to
807 remove those sections from the original .o file.
808 --extract-dwo
810 Extract the contents of all DWARF .dwo sections. See the
811 --strip-dwo option for more information.
812 --file-alignment num
814 Specify the file alignment. Sections in the file will always begin
815 at file offsets which are multiples of this number. This defaults
816 to 512. [This option is specific to PE targets.]
817 --heap reserve
819 --heap reserve,commit
820 Specify the number of bytes of memory to reserve (and optionally
821 commit) to be used as heap for this program. [This option is
822 specific to PE targets.]
823 --image-base value
825 Use value as the base address of your program or dll. This is the
826 lowest memory location that will be used when your program or dll
827 is loaded. To reduce the need to relocate and improve performance
828 of your dlls, each should have a unique base address and not
829 overlap any other dlls. The default is 0x400000 for executables,
830 and 0x10000000 for dlls. [This option is specific to PE targets.]
831 --section-alignment num
833 Sets the section alignment field in the PE header. Sections in
834 memory will always begin at addresses which are a multiple of this
835 number. Defaults to 0x1000. [This option is specific to PE
836 targets.]
837 --stack reserve
839 --stack reserve,commit
840 Specify the number of bytes of memory to reserve (and optionally
841 commit) to be used as stack for this program. [This option is
842 specific to PE targets.]
843 --subsystem which
845 --subsystem which:major
846 --subsystem which:major.minor
847 Specifies the subsystem under which your program will execute. The
848 legal values for which are "native", "windows", "console", "posix",
849 "efi-app", "efi-bsd", "efi-rtd", "sal-rtd", and "xbox". You may
850 optionally set the subsystem version also. Numeric values are also
851 accepted for which. [This option is specific to PE targets.]
852 --extract-symbol
854 Keep the file's section flags and symbols but remove all section
855 data. Specifically, the option:
856 *<removes the contents of all sections;>
858 *<sets the size of every section to zero; and>
859 *<sets the file's start address to zero.>
860 This option is used to build a .sym file for a VxWorks kernel. It
862 can also be a useful way of reducing the size of a --just-symbols
863 linker input file.
864 --compress-debug-sections
866 Compress DWARF debug sections using zlib with SHF_COMPRESSED from
867 the ELF ABI. Note - if compression would actually make a section
868 larger, then it is not compressed.
869 --compress-debug-sections=none
871 --compress-debug-sections=zlib
872 --compress-debug-sections=zlib-gnu
873 --compress-debug-sections=zlib-gabi
874 For ELF files, these options control how DWARF debug sections are
875 compressed. --compress-debug-sections=none is equivalent to
876 --decompress-debug-sections. --compress-debug-sections=zlib and
877 --compress-debug-sections=zlib-gabi are equivalent to
878 --compress-debug-sections. --compress-debug-sections=zlib-gnu
879 compresses DWARF debug sections using zlib. The debug sections are
880 renamed to begin with .zdebug instead of .debug. Note - if
881 compression would actually make a section larger, then it is not
882 compressed nor renamed.
883 --decompress-debug-sections
885 Decompress DWARF debug sections using zlib. The original section
886 names of the compressed sections are restored.
887 --elf-stt-common=yes
889 --elf-stt-common=no
890 For ELF files, these options control whether common symbols should
891 be converted to the "STT_COMMON" or "STT_OBJECT" type.
892 --elf-stt-common=yes converts common symbol type to "STT_COMMON".
893 --elf-stt-common=no converts common symbol type to "STT_OBJECT".
894 --merge-notes
896 --no-merge-notes
897 For ELF files, attempt (or do not attempt) to reduce the size of
898 any SHT_NOTE type sections by removing duplicate notes.
899 -V
901 --version
902 Show the version number of objcopy.
903 --verilog-data-width=bytes
905 For Verilog output, this options controls the number of bytes
906 converted for each output data element. The input target controls
907 the endianness of the conversion.
908 -v
910 --verbose
911 Verbose output: list all object files modified. In the case of
912 archives, objcopy -V lists all members of the archive.
913 --help
915 Show a summary of the options to objcopy.
916 --info
918 Display a list showing all architectures and object formats
919 available.
920 @file
922 Read command-line options from file. The options read are inserted
923 in place of the original @file option. If file does not exist, or
924 cannot be read, then the option will be treated literally, and not
925 removed.
926 Options in file are separated by whitespace. A whitespace
928 character may be included in an option by surrounding the entire
929 option in either single or double quotes. Any character (including
930 a backslash) may be included by prefixing the character to be
931 included with a backslash. The file may itself contain additional
932 @file options; any such options will be processed recursively.
933
935 ld(1), objdump(1), and the Info entries for binutils.
936
938 Copyright (c) 1991-2022 Free Software Foundation, Inc.
939 Permission is granted to copy, distribute and/or modify this document
941 under the terms of the GNU Free Documentation License, Version 1.3 or
942 any later version published by the Free Software Foundation; with no
943 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
944 Texts. A copy of the license is included in the section entitled "GNU
945 Free Documentation License".
946binutils-2.38 2022-11-16 OBJCOPY(1)