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 [-N symbolname|--strip-symbol=symbolname]
18 [--strip-unneeded-symbol=symbolname]
19 [-G symbolname|--keep-global-symbol=symbolname]
20 [--localize-hidden]
21 [-L symbolname|--localize-symbol=symbolname]
22 [--globalize-symbol=symbolname]
23 [--globalize-symbols=filename]
24 [-W symbolname|--weaken-symbol=symbolname]
25 [-w|--wildcard]
26 [-x|--discard-all]
27 [-X|--discard-locals]
28 [-b byte|--byte=byte]
29 [-i [breadth]|--interleave[=breadth]]
30 [--interleave-width=width]
31 [-j sectionpattern|--only-section=sectionpattern]
32 [-R sectionpattern|--remove-section=sectionpattern]
33 [--keep-section=sectionpattern]
34 [--remove-relocations=sectionpattern]
35 [-p|--preserve-dates]
36 [-D|--enable-deterministic-archives]
37 [-U|--disable-deterministic-archives]
38 [--debugging]
39 [--gap-fill=val]
40 [--pad-to=address]
41 [--set-start=val]
42 [--adjust-start=incr]
43 [--change-addresses=incr]
44 [--change-section-address sectionpattern{=,+,-}val]
45 [--change-section-lma sectionpattern{=,+,-}val]
46 [--change-section-vma sectionpattern{=,+,-}val]
47 [--change-warnings] [--no-change-warnings]
48 [--set-section-flags sectionpattern=flags]
49 [--set-section-alignment sectionpattern=align]
50 [--add-section sectionname=filename]
51 [--dump-section sectionname=filename]
52 [--update-section sectionname=filename]
53 [--rename-section oldname=newname[,flags]]
54 [--long-section-names {enable,disable,keep}]
55 [--change-leading-char] [--remove-leading-char]
56 [--reverse-bytes=num]
57 [--srec-len=ival] [--srec-forceS3]
58 [--redefine-sym old=new]
59 [--redefine-syms=filename]
60 [--weaken]
61 [--keep-symbols=filename]
62 [--strip-symbols=filename]
63 [--strip-unneeded-symbols=filename]
64 [--keep-global-symbols=filename]
65 [--localize-symbols=filename]
66 [--weaken-symbols=filename]
67 [--add-symbol name=[section:]value[,flags]]
68 [--alt-machine-code=index]
69 [--prefix-symbols=string]
70 [--prefix-sections=string]
71 [--prefix-alloc-sections=string]
72 [--add-gnu-debuglink=path-to-file]
73 [--keep-file-symbols]
74 [--only-keep-debug]
75 [--strip-dwo]
76 [--extract-dwo]
77 [--extract-symbol]
78 [--writable-text]
79 [--readonly-text]
80 [--pure]
81 [--impure]
82 [--file-alignment=num]
83 [--heap=size]
84 [--image-base=address]
85 [--section-alignment=num]
86 [--stack=size]
87 [--subsystem=which:major.minor]
88 [--compress-debug-sections]
89 [--decompress-debug-sections]
90 [--elf-stt-common=val]
91 [--merge-notes]
92 [--no-merge-notes]
93 [--verilog-data-width=val]
94 [-v|--verbose]
95 [-V|--version]
96 [--help] [--info]
97 infile [outfile]
98
100 The GNU objcopy utility copies the contents of an object file to
101 another. objcopy uses the GNU BFD Library to read and write the object
102 files. It can write the destination object file in a format different
103 from that of the source object file. The exact behavior of objcopy is
104 controlled by command-line options. Note that objcopy should be able
105 to copy a fully linked file between any two formats. However, copying a
106 relocatable object file between any two formats may not work as
107 expected.
108 objcopy creates temporary files to do its translations and deletes them
110 afterward. objcopy uses BFD to do all its translation work; it has
111 access to all the formats described in BFD and thus is able to
112 recognize most formats without being told explicitly.
113 objcopy can be used to generate S-records by using an output target of
115 srec (e.g., use -O srec).
116 objcopy can be used to generate a raw binary file by using an output
118 target of binary (e.g., use -O binary). When objcopy generates a raw
119 binary file, it will essentially produce a memory dump of the contents
120 of the input object file. All symbols and relocation information will
121 be discarded. The memory dump will start at the load address of the
122 lowest section copied into the output file.
123 When generating an S-record or a raw binary file, it may be helpful to
125 use -S to remove sections containing debugging information. In some
126 cases -R will be useful to remove sections which contain information
127 that is not needed by the binary file.
128 Note---objcopy is not able to change the endianness of its input files.
130 If the input format has an endianness (some formats do not), objcopy
131 can only copy the inputs into file formats that have the same
132 endianness or which have no endianness (e.g., srec). (However, see the
133 --reverse-bytes option.)
134
136 infile
137 outfile
138 The input and output files, respectively. If you do not specify
139 outfile, objcopy creates a temporary file and destructively renames
140 the result with the name of infile.
141 -I bfdname
143 --input-target=bfdname
144 Consider the source file's object format to be bfdname, rather than
145 attempting to deduce it.
146 -O bfdname
148 --output-target=bfdname
149 Write the output file using the object format bfdname.
150 -F bfdname
152 --target=bfdname
153 Use bfdname as the object format for both the input and the output
154 file; i.e., simply transfer data from source to destination with no
155 translation.
156 -B bfdarch
158 --binary-architecture=bfdarch
159 Useful when transforming a architecture-less input file into an
160 object file. In this case the output architecture can be set to
161 bfdarch. This option will be ignored if the input file has a known
162 bfdarch. You can access this binary data inside a program by
163 referencing the special symbols that are created by the conversion
164 process. These symbols are called _binary_objfile_start,
165 _binary_objfile_end and _binary_objfile_size. e.g. you can
166 transform a picture file into an object file and then access it in
167 your code using these symbols.
168 -j sectionpattern
170 --only-section=sectionpattern
171 Copy only the indicated sections from the input file to the output
172 file. This option may be given more than once. Note that using
173 this option inappropriately may make the output file unusable.
174 Wildcard characters are accepted in sectionpattern.
175 If the first character of sectionpattern is the exclamation point
177 (!) then matching sections will not be copied, even if earlier use
178 of --only-section on the same command line would otherwise copy it.
179 For example:
180 --only-section=.text.* --only-section=!.text.foo
182 will copy all sectinos maching '.text.*' but not the section
184 '.text.foo'.
185 -R sectionpattern
187 --remove-section=sectionpattern
188 Remove any section matching sectionpattern from the output file.
189 This option may be given more than once. Note that using this
190 option inappropriately may make the output file unusable. Wildcard
191 characters are accepted in sectionpattern. Using both the -j and
192 -R options together results in undefined behaviour.
193 If the first character of sectionpattern is the exclamation point
195 (!) then matching sections will not be removed even if an earlier
196 use of --remove-section on the same command line would otherwise
197 remove it. For example:
198 --remove-section=.text.* --remove-section=!.text.foo
200 will remove all sections matching the pattern '.text.*', but will
202 not remove the section '.text.foo'.
203 --keep-section=sectionpattern
205 When removing sections from the output file, keep sections that
206 match sectionpattern.
207 --remove-relocations=sectionpattern
209 Remove non-dynamic relocations from the output file for any section
210 matching sectionpattern. This option may be given more than once.
211 Note that using this option inappropriately may make the output
212 file unusable, and attempting to remove a dynamic relocation
213 section such as .rela.plt from an executable or shared library with
214 --remove-relocations=.plt will not work. Wildcard characters are
215 accepted in sectionpattern. For example:
216 --remove-relocations=.text.*
218 will remove the relocations for all sections matching the pattern
220 '.text.*'.
221 If the first character of sectionpattern is the exclamation point
223 (!) then matching sections will not have their relocation removed
224 even if an earlier use of --remove-relocations on the same command
225 line would otherwise cause the relocations to be removed. For
226 example:
227 --remove-relocations=.text.* --remove-relocations=!.text.foo
229 will remove all relocations for sections matching the pattern
231 '.text.*', but will not remove relocations for the section
232 '.text.foo'.
233 -S
235 --strip-all
236 Do not copy relocation and symbol information from the source file.
237 -g
239 --strip-debug
240 Do not copy debugging symbols or sections from the source file.
241 --strip-unneeded
243 Strip all symbols that are not needed for relocation processing.
244 -K symbolname
246 --keep-symbol=symbolname
247 When stripping symbols, keep symbol symbolname even if it would
248 normally be stripped. This option may be given more than once.
249 -N symbolname
251 --strip-symbol=symbolname
252 Do not copy symbol symbolname from the source file. This option
253 may be given more than once.
254 --strip-unneeded-symbol=symbolname
256 Do not copy symbol symbolname from the source file unless it is
257 needed by a relocation. This option may be given more than once.
258 -G symbolname
260 --keep-global-symbol=symbolname
261 Keep only symbol symbolname global. Make all other symbols local
262 to the file, so that they are not visible externally. This option
263 may be given more than once. Note: this option cannot be used in
264 conjunction with the --globalize-symbol or --globalize-symbols
265 options.
266 --localize-hidden
268 In an ELF object, mark all symbols that have hidden or internal
269 visibility as local. This option applies on top of symbol-specific
270 localization options such as -L.
271 -L symbolname
273 --localize-symbol=symbolname
274 Convert a global or weak symbol called symbolname into a local
275 symbol, so that it is not visible externally. This option may be
276 given more than once. Note - unique symbols are not converted.
277 -W symbolname
279 --weaken-symbol=symbolname
280 Make symbol symbolname weak. This option may be given more than
281 once.
282 --globalize-symbol=symbolname
284 Give symbol symbolname global scoping so that it is visible outside
285 of the file in which it is defined. This option may be given more
286 than once. Note: this option cannot be used in conjunction with
287 the -G or --keep-global-symbol options.
288 -w
290 --wildcard
291 Permit regular expressions in symbolnames used in other command
292 line options. The question mark (?), asterisk (*), backslash (\)
293 and square brackets ([]) operators can be used anywhere in the
294 symbol name. If the first character of the symbol name is the
295 exclamation point (!) then the sense of the switch is reversed for
296 that symbol. For example:
297 -w -W !foo -W fo*
299 would cause objcopy to weaken all symbols that start with "fo"
301 except for the symbol "foo".
302 -x
304 --discard-all
305 Do not copy non-global symbols from the source file.
306 -X
308 --discard-locals
309 Do not copy compiler-generated local symbols. (These usually start
310 with L or ..)
311 -b byte
313 --byte=byte
314 If interleaving has been enabled via the --interleave option then
315 start the range of bytes to keep at the byteth byte. byte can be
316 in the range from 0 to breadth-1, where breadth is the value given
317 by the --interleave option.
318 -i [breadth]
320 --interleave[=breadth]
321 Only copy a range out of every breadth bytes. (Header data is not
322 affected). Select which byte in the range begins the copy with the
323 --byte option. Select the width of the range with the
324 --interleave-width option.
325 This option is useful for creating files to program ROM. It is
327 typically used with an "srec" output target. Note that objcopy
328 will complain if you do not specify the --byte option as well.
329 The default interleave breadth is 4, so with --byte set to 0,
331 objcopy would copy the first byte out of every four bytes from the
332 input to the output.
333 --interleave-width=width
335 When used with the --interleave option, copy width bytes at a time.
336 The start of the range of bytes to be copied is set by the --byte
337 option, and the extent of the range is set with the --interleave
338 option.
339 The default value for this option is 1. The value of width plus
341 the byte value set by the --byte option must not exceed the
342 interleave breadth set by the --interleave option.
343 This option can be used to create images for two 16-bit flashes
345 interleaved in a 32-bit bus by passing -b 0 -i 4
346 --interleave-width=2 and -b 2 -i 4 --interleave-width=2 to two
347 objcopy commands. If the input was '12345678' then the outputs
348 would be '1256' and '3478' respectively.
349 -p
351 --preserve-dates
352 Set the access and modification dates of the output file to be the
353 same as those of the input file.
354 -D
356 --enable-deterministic-archives
357 Operate in deterministic mode. When copying archive members and
358 writing the archive index, use zero for UIDs, GIDs, timestamps, and
359 use consistent file modes for all files.
360 If binutils was configured with --enable-deterministic-archives,
362 then this mode is on by default. It can be disabled with the -U
363 option, below.
364 -U
366 --disable-deterministic-archives
367 Do not operate in deterministic mode. This is the inverse of the
368 -D option, above: when copying archive members and writing the
369 archive index, use their actual UID, GID, timestamp, and file mode
370 values.
371 This is the default unless binutils was configured with
373 --enable-deterministic-archives.
374 --debugging
376 Convert debugging information, if possible. This is not the
377 default because only certain debugging formats are supported, and
378 the conversion process can be time consuming.
379 --gap-fill val
381 Fill gaps between sections with val. This operation applies to the
382 load address (LMA) of the sections. It is done by increasing the
383 size of the section with the lower address, and filling in the
384 extra space created with val.
385 --pad-to address
387 Pad the output file up to the load address address. This is done
388 by increasing the size of the last section. The extra space is
389 filled in with the value specified by --gap-fill (default zero).
390 --set-start val
392 Set the start address (also known as the entry address) of the new
393 file to val. Not all object file formats support setting the start
394 address.
395 --change-start incr
397 --adjust-start incr
398 Change the start address (also known as the entry address) by
399 adding incr. Not all object file formats support setting the start
400 address.
401 --change-addresses incr
403 --adjust-vma incr
404 Change the VMA and LMA addresses of all sections, as well as the
405 start address, by adding incr. Some object file formats do not
406 permit section addresses to be changed arbitrarily. Note that this
407 does not relocate the sections; if the program expects sections to
408 be loaded at a certain address, and this option is used to change
409 the sections such that they are loaded at a different address, the
410 program may fail.
411 --change-section-address sectionpattern{=,+,-}val
413 --adjust-section-vma sectionpattern{=,+,-}val
414 Set or change both the VMA address and the LMA address of any
415 section matching sectionpattern. If = is used, the section address
416 is set to val. Otherwise, val is added to or subtracted from the
417 section address. See the comments under --change-addresses, above.
418 If sectionpattern does not match any sections in the input file, a
419 warning will be issued, unless --no-change-warnings is used.
420 --change-section-lma sectionpattern{=,+,-}val
422 Set or change the LMA address of any sections matching
423 sectionpattern. The LMA address is the address where the section
424 will be loaded into memory at program load time. Normally this is
425 the same as the VMA address, which is the address of the section at
426 program run time, but on some systems, especially those where a
427 program is held in ROM, the two can be different. If = is used,
428 the section address is set to val. Otherwise, val is added to or
429 subtracted from the section address. See the comments under
430 --change-addresses, above. If sectionpattern does not match any
431 sections in the input file, a warning will be issued, unless
432 --no-change-warnings is used.
433 --change-section-vma sectionpattern{=,+,-}val
435 Set or change the VMA address of any section matching
436 sectionpattern. The VMA address is the address where the section
437 will be located once the program has started executing. Normally
438 this is the same as the LMA address, which is the address where the
439 section will be loaded into memory, but on some systems, especially
440 those where a program is held in ROM, the two can be different. If
441 = is used, the section address is set to val. Otherwise, val is
442 added to or subtracted from the section address. See the comments
443 under --change-addresses, above. If sectionpattern does not match
444 any sections in the input file, a warning will be issued, unless
445 --no-change-warnings is used.
446 --change-warnings
448 --adjust-warnings
449 If --change-section-address or --change-section-lma or
450 --change-section-vma is used, and the section pattern does not
451 match any sections, issue a warning. This is the default.
452 --no-change-warnings
454 --no-adjust-warnings
455 Do not issue a warning if --change-section-address or
456 --adjust-section-lma or --adjust-section-vma is used, even if the
457 section pattern does not match any sections.
458 --set-section-flags sectionpattern=flags
460 Set the flags for any sections matching sectionpattern. The flags
461 argument is a comma separated string of flag names. The recognized
462 names are alloc, contents, load, noload, readonly, code, data, rom,
463 exclude, share, and debug. You can set the contents flag for a
464 section which does not have contents, but it is not meaningful to
465 clear the contents flag of a section which does have contents--just
466 remove the section instead. Not all flags are meaningful for all
467 object file formats. In particular the share flag is only
468 meaningful for COFF format files and not for ELF format files.
469 --set-section-alignment sectionpattern=align
471 Set the alignment for any sections matching sectionpattern. align
472 specifies the alignment in bytes and must be a power of two, i.e.
473 1, 2, 4, 8....
474 --add-section sectionname=filename
476 Add a new section named sectionname while copying the file. The
477 contents of the new section are taken from the file filename. The
478 size of the section will be the size of the file. This option only
479 works on file formats which can support sections with arbitrary
480 names. Note - it may be necessary to use the --set-section-flags
481 option to set the attributes of the newly created section.
482 --dump-section sectionname=filename
484 Place the contents of section named sectionname into the file
485 filename, overwriting any contents that may have been there
486 previously. This option is the inverse of --add-section. This
487 option is similar to the --only-section option except that it does
488 not create a formatted file, it just dumps the contents as raw
489 binary data, without applying any relocations. The option can be
490 specified more than once.
491 --update-section sectionname=filename
493 Replace the existing contents of a section named sectionname with
494 the contents of file filename. The size of the section will be
495 adjusted to the size of the file. The section flags for
496 sectionname will be unchanged. For ELF format files the section to
497 segment mapping will also remain unchanged, something which is not
498 possible using --remove-section followed by --add-section. The
499 option can be specified more than once.
500 Note - it is possible to use --rename-section and --update-section
502 to both update and rename a section from one command line. In this
503 case, pass the original section name to --update-section, and the
504 original and new section names to --rename-section.
505 --add-symbol name=[section:]value[,flags]
507 Add a new symbol named name while copying the file. This option
508 may be specified multiple times. If the section is given, the
509 symbol will be associated with and relative to that section,
510 otherwise it will be an ABS symbol. Specifying an undefined
511 section will result in a fatal error. There is no check for the
512 value, it will be taken as specified. Symbol flags can be
513 specified and not all flags will be meaningful for all object file
514 formats. By default, the symbol will be global. The special flag
515 'before=othersym' will insert the new symbol in front of the
516 specified othersym, otherwise the symbol(s) will be added at the
517 end of the symbol table in the order they appear.
518 --rename-section oldname=newname[,flags]
520 Rename a section from oldname to newname, optionally changing the
521 section's flags to flags in the process. This has the advantage
522 over using a linker script to perform the rename in that the output
523 stays as an object file and does not become a linked executable.
524 This option accepts the same set of flags as the
525 --sect-section-flags option.
526 This option is particularly helpful when the input format is
528 binary, since this will always create a section called .data. If
529 for example, you wanted instead to create a section called .rodata
530 containing binary data you could use the following command line to
531 achieve it:
532 objcopy -I binary -O <output_format> -B <architecture> \
534 --rename-section .data=.rodata,alloc,load,readonly,data,contents \
535 <input_binary_file> <output_object_file>
536 --long-section-names {enable,disable,keep}
538 Controls the handling of long section names when processing "COFF"
539 and "PE-COFF" object formats. The default behaviour, keep, is to
540 preserve long section names if any are present in the input file.
541 The enable and disable options forcibly enable or disable the use
542 of long section names in the output object; when disable is in
543 effect, any long section names in the input object will be
544 truncated. The enable option will only emit long section names if
545 any are present in the inputs; this is mostly the same as keep, but
546 it is left undefined whether the enable option might force the
547 creation of an empty string table in the output file.
548 --change-leading-char
550 Some object file formats use special characters at the start of
551 symbols. The most common such character is underscore, which
552 compilers often add before every symbol. This option tells objcopy
553 to change the leading character of every symbol when it converts
554 between object file formats. If the object file formats use the
555 same leading character, this option has no effect. Otherwise, it
556 will add a character, or remove a character, or change a character,
557 as appropriate.
558 --remove-leading-char
560 If the first character of a global symbol is a special symbol
561 leading character used by the object file format, remove the
562 character. The most common symbol leading character is underscore.
563 This option will remove a leading underscore from all global
564 symbols. This can be useful if you want to link together objects
565 of different file formats with different conventions for symbol
566 names. This is different from --change-leading-char because it
567 always changes the symbol name when appropriate, regardless of the
568 object file format of the output file.
569 --reverse-bytes=num
571 Reverse the bytes in a section with output contents. A section
572 length must be evenly divisible by the value given in order for the
573 swap to be able to take place. Reversing takes place before the
574 interleaving is performed.
575 This option is used typically in generating ROM images for
577 problematic target systems. For example, on some target boards,
578 the 32-bit words fetched from 8-bit ROMs are re-assembled in
579 little-endian byte order regardless of the CPU byte order.
580 Depending on the programming model, the endianness of the ROM may
581 need to be modified.
582 Consider a simple file with a section containing the following
584 eight bytes: 12345678.
585 Using --reverse-bytes=2 for the above example, the bytes in the
587 output file would be ordered 21436587.
588 Using --reverse-bytes=4 for the above example, the bytes in the
590 output file would be ordered 43218765.
591 By using --reverse-bytes=2 for the above example, followed by
593 --reverse-bytes=4 on the output file, the bytes in the second
594 output file would be ordered 34127856.
595 --srec-len=ival
597 Meaningful only for srec output. Set the maximum length of the
598 Srecords being produced to ival. This length covers both address,
599 data and crc fields.
600 --srec-forceS3
602 Meaningful only for srec output. Avoid generation of S1/S2
603 records, creating S3-only record format.
604 --redefine-sym old=new
606 Change the name of a symbol old, to new. This can be useful when
607 one is trying link two things together for which you have no
608 source, and there are name collisions.
609 --redefine-syms=filename
611 Apply --redefine-sym to each symbol pair "old new" listed in the
612 file filename. filename is simply a flat file, with one symbol
613 pair per line. Line comments may be introduced by the hash
614 character. This option may be given more than once.
615 --weaken
617 Change all global symbols in the file to be weak. This can be
618 useful when building an object which will be linked against other
619 objects using the -R option to the linker. This option is only
620 effective when using an object file format which supports weak
621 symbols.
622 --keep-symbols=filename
624 Apply --keep-symbol option to each symbol listed in the file
625 filename. filename is simply a flat file, with one symbol name per
626 line. Line comments may be introduced by the hash character. This
627 option may be given more than once.
628 --strip-symbols=filename
630 Apply --strip-symbol option to each symbol listed in the file
631 filename. filename is simply a flat file, with one symbol name per
632 line. Line comments may be introduced by the hash character. This
633 option may be given more than once.
634 --strip-unneeded-symbols=filename
636 Apply --strip-unneeded-symbol option to each symbol listed in the
637 file filename. filename is simply a flat file, with one symbol
638 name per line. Line comments may be introduced by the hash
639 character. This option may be given more than once.
640 --keep-global-symbols=filename
642 Apply --keep-global-symbol option to each symbol listed in the file
643 filename. filename is simply a flat file, with one symbol name per
644 line. Line comments may be introduced by the hash character. This
645 option may be given more than once.
646 --localize-symbols=filename
648 Apply --localize-symbol option to each symbol listed in the file
649 filename. filename is simply a flat file, with one symbol name per
650 line. Line comments may be introduced by the hash character. This
651 option may be given more than once.
652 --globalize-symbols=filename
654 Apply --globalize-symbol option to each symbol listed in the file
655 filename. filename is simply a flat file, with one symbol name per
656 line. Line comments may be introduced by the hash character. This
657 option may be given more than once. Note: this option cannot be
658 used in conjunction with the -G or --keep-global-symbol options.
659 --weaken-symbols=filename
661 Apply --weaken-symbol option to each symbol listed in the file
662 filename. filename is simply a flat file, with one symbol name per
663 line. Line comments may be introduced by the hash character. This
664 option may be given more than once.
665 --alt-machine-code=index
667 If the output architecture has alternate machine codes, use the
668 indexth code instead of the default one. This is useful in case a
669 machine is assigned an official code and the tool-chain adopts the
670 new code, but other applications still depend on the original code
671 being used. For ELF based architectures if the index alternative
672 does not exist then the value is treated as an absolute number to
673 be stored in the e_machine field of the ELF header.
674 --writable-text
676 Mark the output text as writable. This option isn't meaningful for
677 all object file formats.
678 --readonly-text
680 Make the output text write protected. This option isn't meaningful
681 for all object file formats.
682 --pure
684 Mark the output file as demand paged. This option isn't meaningful
685 for all object file formats.
686 --impure
688 Mark the output file as impure. This option isn't meaningful for
689 all object file formats.
690 --prefix-symbols=string
692 Prefix all symbols in the output file with string.
693 --prefix-sections=string
695 Prefix all section names in the output file with string.
696 --prefix-alloc-sections=string
698 Prefix all the names of all allocated sections in the output file
699 with string.
700 --add-gnu-debuglink=path-to-file
702 Creates a .gnu_debuglink section which contains a reference to
703 path-to-file and adds it to the output file. Note: the file at
704 path-to-file must exist. Part of the process of adding the
705 .gnu_debuglink section involves embedding a checksum of the
706 contents of the debug info file into the section.
707 If the debug info file is built in one location but it is going to
709 be installed at a later time into a different location then do not
710 use the path to the installed location. The --add-gnu-debuglink
711 option will fail because the installed file does not exist yet.
712 Instead put the debug info file in the current directory and use
713 the --add-gnu-debuglink option without any directory components,
714 like this:
715 objcopy --add-gnu-debuglink=foo.debug
717 At debug time the debugger will attempt to look for the separate
719 debug info file in a set of known locations. The exact set of
720 these locations varies depending upon the distribution being used,
721 but it typically includes:
722 "* The same directory as the executable."
724 "* A sub-directory of the directory containing the executable"
725 called .debug
726 "* A global debug directory such as /usr/lib/debug."
728 As long as the debug info file has been installed into one of these
730 locations before the debugger is run everything should work
731 correctly.
732 --keep-file-symbols
734 When stripping a file, perhaps with --strip-debug or
735 --strip-unneeded, retain any symbols specifying source file names,
736 which would otherwise get stripped.
737 --only-keep-debug
739 Strip a file, removing contents of any sections that would not be
740 stripped by --strip-debug and leaving the debugging sections
741 intact. In ELF files, this preserves all note sections in the
742 output.
743 Note - the section headers of the stripped sections are preserved,
745 including their sizes, but the contents of the section are
746 discarded. The section headers are preserved so that other tools
747 can match up the debuginfo file with the real executable, even if
748 that executable has been relocated to a different address space.
749 The intention is that this option will be used in conjunction with
751 --add-gnu-debuglink to create a two part executable. One a
752 stripped binary which will occupy less space in RAM and in a
753 distribution and the second a debugging information file which is
754 only needed if debugging abilities are required. The suggested
755 procedure to create these files is as follows:
756 1.<Link the executable as normal. Assuming that it is called>
758 "foo" then...
759 1.<Run "objcopy --only-keep-debug foo foo.dbg" to>
761 create a file containing the debugging info.
762 1.<Run "objcopy --strip-debug foo" to create a>
764 stripped executable.
765 1.<Run "objcopy --add-gnu-debuglink=foo.dbg foo">
767 to add a link to the debugging info into the stripped
768 executable.
769 Note---the choice of ".dbg" as an extension for the debug info file
771 is arbitrary. Also the "--only-keep-debug" step is optional. You
772 could instead do this:
773 1.<Link the executable as normal.>
775 1.<Copy "foo" to "foo.full">
776 1.<Run "objcopy --strip-debug foo">
777 1.<Run "objcopy --add-gnu-debuglink=foo.full foo">
778 i.e., the file pointed to by the --add-gnu-debuglink can be the
780 full executable. It does not have to be a file created by the
781 --only-keep-debug switch.
782 Note---this switch is only intended for use on fully linked files.
784 It does not make sense to use it on object files where the
785 debugging information may be incomplete. Besides the gnu_debuglink
786 feature currently only supports the presence of one filename
787 containing debugging information, not multiple filenames on a one-
788 per-object-file basis.
789 --strip-dwo
791 Remove the contents of all DWARF .dwo sections, leaving the
792 remaining debugging sections and all symbols intact. This option
793 is intended for use by the compiler as part of the -gsplit-dwarf
794 option, which splits debug information between the .o file and a
795 separate .dwo file. The compiler generates all debug information
796 in the same file, then uses the --extract-dwo option to copy the
797 .dwo sections to the .dwo file, then the --strip-dwo option to
798 remove those sections from the original .o file.
799 --extract-dwo
801 Extract the contents of all DWARF .dwo sections. See the
802 --strip-dwo option for more information.
803 --file-alignment num
805 Specify the file alignment. Sections in the file will always begin
806 at file offsets which are multiples of this number. This defaults
807 to 512. [This option is specific to PE targets.]
808 --heap reserve
810 --heap reserve,commit
811 Specify the number of bytes of memory to reserve (and optionally
812 commit) to be used as heap for this program. [This option is
813 specific to PE targets.]
814 --image-base value
816 Use value as the base address of your program or dll. This is the
817 lowest memory location that will be used when your program or dll
818 is loaded. To reduce the need to relocate and improve performance
819 of your dlls, each should have a unique base address and not
820 overlap any other dlls. The default is 0x400000 for executables,
821 and 0x10000000 for dlls. [This option is specific to PE targets.]
822 --section-alignment num
824 Sets the section alignment field in the PE header. Sections in
825 memory will always begin at addresses which are a multiple of this
826 number. Defaults to 0x1000. [This option is specific to PE
827 targets.]
828 --stack reserve
830 --stack reserve,commit
831 Specify the number of bytes of memory to reserve (and optionally
832 commit) to be used as stack for this program. [This option is
833 specific to PE targets.]
834 --subsystem which
836 --subsystem which:major
837 --subsystem which:major.minor
838 Specifies the subsystem under which your program will execute. The
839 legal values for which are "native", "windows", "console", "posix",
840 "efi-app", "efi-bsd", "efi-rtd", "sal-rtd", and "xbox". You may
841 optionally set the subsystem version also. Numeric values are also
842 accepted for which. [This option is specific to PE targets.]
843 --extract-symbol
845 Keep the file's section flags and symbols but remove all section
846 data. Specifically, the option:
847 *<removes the contents of all sections;>
849 *<sets the size of every section to zero; and>
850 *<sets the file's start address to zero.>
851 This option is used to build a .sym file for a VxWorks kernel. It
853 can also be a useful way of reducing the size of a --just-symbols
854 linker input file.
855 --compress-debug-sections
857 Compress DWARF debug sections using zlib with SHF_COMPRESSED from
858 the ELF ABI. Note - if compression would actually make a section
859 larger, then it is not compressed.
860 --compress-debug-sections=none
862 --compress-debug-sections=zlib
863 --compress-debug-sections=zlib-gnu
864 --compress-debug-sections=zlib-gabi
865 For ELF files, these options control how DWARF debug sections are
866 compressed. --compress-debug-sections=none is equivalent to
867 --decompress-debug-sections. --compress-debug-sections=zlib and
868 --compress-debug-sections=zlib-gabi are equivalent to
869 --compress-debug-sections. --compress-debug-sections=zlib-gnu
870 compresses DWARF debug sections using zlib. The debug sections are
871 renamed to begin with .zdebug instead of .debug. Note - if
872 compression would actually make a section larger, then it is not
873 compressed nor renamed.
874 --decompress-debug-sections
876 Decompress DWARF debug sections using zlib. The original section
877 names of the compressed sections are restored.
878 --elf-stt-common=yes
880 --elf-stt-common=no
881 For ELF files, these options control whether common symbols should
882 be converted to the "STT_COMMON" or "STT_OBJECT" type.
883 --elf-stt-common=yes converts common symbol type to "STT_COMMON".
884 --elf-stt-common=no converts common symbol type to "STT_OBJECT".
885 --merge-notes
887 --no-merge-notes
888 For ELF files, attempt (or do not attempt) to reduce the size of
889 any SHT_NOTE type sections by removing duplicate notes.
890 -V
892 --version
893 Show the version number of objcopy.
894 --verilog-data-width=bytes
896 For Verilog output, this options controls the number of bytes
897 converted for each output data element. The input target controls
898 the endianness of the conversion.
899 -v
901 --verbose
902 Verbose output: list all object files modified. In the case of
903 archives, objcopy -V lists all members of the archive.
904 --help
906 Show a summary of the options to objcopy.
907 --info
909 Display a list showing all architectures and object formats
910 available.
911 @file
913 Read command-line options from file. The options read are inserted
914 in place of the original @file option. If file does not exist, or
915 cannot be read, then the option will be treated literally, and not
916 removed.
917 Options in file are separated by whitespace. A whitespace
919 character may be included in an option by surrounding the entire
920 option in either single or double quotes. Any character (including
921 a backslash) may be included by prefixing the character to be
922 included with a backslash. The file may itself contain additional
923 @file options; any such options will be processed recursively.
924
926 ld(1), objdump(1), and the Info entries for binutils.
927
929 Copyright (c) 1991-2020 Free Software Foundation, Inc.
930 Permission is granted to copy, distribute and/or modify this document
932 under the terms of the GNU Free Documentation License, Version 1.3 or
933 any later version published by the Free Software Foundation; with no
934 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
935 Texts. A copy of the license is included in the section entitled "GNU
936 Free Documentation License".
937binutils-2.35 2020-07-24 OBJCOPY(1)