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 [breadth]|--interleave[=breadth]]
28 [--interleave-width=width]
29 [-j sectionpattern|--only-section=sectionpattern]
30 [-R sectionpattern|--remove-section=sectionpattern]
31 [-p|--preserve-dates]
32 [-D|--enable-deterministic-archives]
33 [-U|--disable-deterministic-archives]
34 [--debugging]
35 [--gap-fill=val]
36 [--pad-to=address]
37 [--set-start=val]
38 [--adjust-start=incr]
39 [--change-addresses=incr]
40 [--change-section-address sectionpattern{=,+,-}val]
41 [--change-section-lma sectionpattern{=,+,-}val]
42 [--change-section-vma sectionpattern{=,+,-}val]
43 [--change-warnings] [--no-change-warnings]
44 [--set-section-flags sectionpattern=flags]
45 [--add-section sectionname=filename]
46 [--dump-section sectionname=filename]
47 [--update-section sectionname=filename]
48 [--rename-section oldname=newname[,flags]]
49 [--long-section-names {enable,disable,keep}]
50 [--change-leading-char] [--remove-leading-char]
51 [--reverse-bytes=num]
52 [--srec-len=ival] [--srec-forceS3]
53 [--redefine-sym old=new]
54 [--redefine-syms=filename]
55 [--weaken]
56 [--keep-symbols=filename]
57 [--strip-symbols=filename]
58 [--strip-unneeded-symbols=filename]
59 [--keep-global-symbols=filename]
60 [--localize-symbols=filename]
61 [--globalize-symbols=filename]
62 [--weaken-symbols=filename]
63 [--add-symbol name=[section:]value[,flags]
64 [--alt-machine-code=index]
65 [--prefix-symbols=string]
66 [--prefix-sections=string]
67 [--prefix-alloc-sections=string]
68 [--add-gnu-debuglink=path-to-file]
69 [--keep-file-symbols]
70 [--only-keep-debug]
71 [--strip-dwo]
72 [--extract-dwo]
73 [--extract-symbol]
74 [--writable-text]
75 [--readonly-text]
76 [--pure]
77 [--impure]
78 [--file-alignment=num]
79 [--heap=size]
80 [--image-base=address]
81 [--section-alignment=num]
82 [--stack=size]
83 [--subsystem=which:major.minor]
84 [--compress-debug-sections]
85 [--decompress-debug-sections]
86 [--dwarf-depth=n]
87 [--dwarf-start=n]
88 [-v|--verbose]
89 [-V|--version]
90 [--help] [--info]
91 infile [outfile]
92
94 The GNU objcopy utility copies the contents of an object file to
95 another. objcopy uses the GNU BFD Library to read and write the object
96 files. It can write the destination object file in a format different
97 from that of the source object file. The exact behavior of objcopy is
98 controlled by command-line options. Note that objcopy should be able
99 to copy a fully linked file between any two formats. However, copying a
100 relocatable object file between any two formats may not work as
101 expected.
102 objcopy creates temporary files to do its translations and deletes them
104 afterward. objcopy uses BFD to do all its translation work; it has
105 access to all the formats described in BFD and thus is able to
106 recognize most formats without being told explicitly.
107 objcopy can be used to generate S-records by using an output target of
109 srec (e.g., use -O srec).
110 objcopy can be used to generate a raw binary file by using an output
112 target of binary (e.g., use -O binary). When objcopy generates a raw
113 binary file, it will essentially produce a memory dump of the contents
114 of the input object file. All symbols and relocation information will
115 be discarded. The memory dump will start at the load address of the
116 lowest section copied into the output file.
117 When generating an S-record or a raw binary file, it may be helpful to
119 use -S to remove sections containing debugging information. In some
120 cases -R will be useful to remove sections which contain information
121 that is not needed by the binary file.
122 Note---objcopy is not able to change the endianness of its input files.
124 If the input format has an endianness (some formats do not), objcopy
125 can only copy the inputs into file formats that have the same
126 endianness or which have no endianness (e.g., srec). (However, see the
127 --reverse-bytes option.)
128
130 infile
131 outfile
132 The input and output files, respectively. If you do not specify
133 outfile, objcopy creates a temporary file and destructively renames
134 the result with the name of infile.
135 -I bfdname
137 --input-target=bfdname
138 Consider the source file's object format to be bfdname, rather than
139 attempting to deduce it.
140 -O bfdname
142 --output-target=bfdname
143 Write the output file using the object format bfdname.
144 -F bfdname
146 --target=bfdname
147 Use bfdname as the object format for both the input and the output
148 file; i.e., simply transfer data from source to destination with no
149 translation.
150 -B bfdarch
152 --binary-architecture=bfdarch
153 Useful when transforming a architecture-less input file into an
154 object file. In this case the output architecture can be set to
155 bfdarch. This option will be ignored if the input file has a known
156 bfdarch. You can access this binary data inside a program by
157 referencing the special symbols that are created by the conversion
158 process. These symbols are called _binary_objfile_start,
159 _binary_objfile_end and _binary_objfile_size. e.g. you can
160 transform a picture file into an object file and then access it in
161 your code using these symbols.
162 -j sectionpattern
164 --only-section=sectionpattern
165 Copy only the indicated sections from the input file to the output
166 file. This option may be given more than once. Note that using
167 this option inappropriately may make the output file unusable.
168 Wildcard characters are accepted in sectionpattern.
169 -R sectionpattern
171 --remove-section=sectionpattern
172 Remove any section matching sectionpattern from the output file.
173 This option may be given more than once. Note that using this
174 option inappropriately may make the output file unusable. Wildcard
175 characters are accepted in sectionpattern. Using both the -j and
176 -R options together results in undefined behaviour.
177 -S
179 --strip-all
180 Do not copy relocation and symbol information from the source file.
181 -g
183 --strip-debug
184 Do not copy debugging symbols or sections from the source file.
185 --strip-unneeded
187 Strip all symbols that are not needed for relocation processing.
188 -K symbolname
190 --keep-symbol=symbolname
191 When stripping symbols, keep symbol symbolname even if it would
192 normally be stripped. This option may be given more than once.
193 -N symbolname
195 --strip-symbol=symbolname
196 Do not copy symbol symbolname from the source file. This option
197 may be given more than once.
198 --strip-unneeded-symbol=symbolname
200 Do not copy symbol symbolname from the source file unless it is
201 needed by a relocation. This option may be given more than once.
202 -G symbolname
204 --keep-global-symbol=symbolname
205 Keep only symbol symbolname global. Make all other symbols local
206 to the file, so that they are not visible externally. This option
207 may be given more than once.
208 --localize-hidden
210 In an ELF object, mark all symbols that have hidden or internal
211 visibility as local. This option applies on top of symbol-specific
212 localization options such as -L.
213 -L symbolname
215 --localize-symbol=symbolname
216 Make symbol symbolname local to the file, so that it is not visible
217 externally. This option may be given more than once.
218 -W symbolname
220 --weaken-symbol=symbolname
221 Make symbol symbolname weak. This option may be given more than
222 once.
223 --globalize-symbol=symbolname
225 Give symbol symbolname global scoping so that it is visible outside
226 of the file in which it is defined. This option may be given more
227 than once.
228 -w
230 --wildcard
231 Permit regular expressions in symbolnames used in other command
232 line options. The question mark (?), asterisk (*), backslash (\)
233 and square brackets ([]) operators can be used anywhere in the
234 symbol name. If the first character of the symbol name is the
235 exclamation point (!) then the sense of the switch is reversed for
236 that symbol. For example:
237 -w -W !foo -W fo*
239 would cause objcopy to weaken all symbols that start with "fo"
241 except for the symbol "foo".
242 -x
244 --discard-all
245 Do not copy non-global symbols from the source file.
246 -X
248 --discard-locals
249 Do not copy compiler-generated local symbols. (These usually start
250 with L or ..)
251 -b byte
253 --byte=byte
254 If interleaving has been enabled via the --interleave option then
255 start the range of bytes to keep at the byteth byte. byte can be
256 in the range from 0 to breadth-1, where breadth is the value given
257 by the --interleave option.
258 -i [breadth]
260 --interleave[=breadth]
261 Only copy a range out of every breadth bytes. (Header data is not
262 affected). Select which byte in the range begins the copy with the
263 --byte option. Select the width of the range with the
264 --interleave-width option.
265 This option is useful for creating files to program ROM. It is
267 typically used with an "srec" output target. Note that objcopy
268 will complain if you do not specify the --byte option as well.
269 The default interleave breadth is 4, so with --byte set to 0,
271 objcopy would copy the first byte out of every four bytes from the
272 input to the output.
273 --interleave-width=width
275 When used with the --interleave option, copy width bytes at a time.
276 The start of the range of bytes to be copied is set by the --byte
277 option, and the extent of the range is set with the --interleave
278 option.
279 The default value for this option is 1. The value of width plus
281 the byte value set by the --byte option must not exceed the
282 interleave breadth set by the --interleave option.
283 This option can be used to create images for two 16-bit flashes
285 interleaved in a 32-bit bus by passing -b 0 -i 4
286 --interleave-width=2 and -b 2 -i 4 --interleave-width=2 to two
287 objcopy commands. If the input was '12345678' then the outputs
288 would be '1256' and '3478' respectively.
289 -p
291 --preserve-dates
292 Set the access and modification dates of the output file to be the
293 same as those of the input file.
294 -D
296 --enable-deterministic-archives
297 Operate in deterministic mode. When copying archive members and
298 writing the archive index, use zero for UIDs, GIDs, timestamps, and
299 use consistent file modes for all files.
300 If binutils was configured with --enable-deterministic-archives,
302 then this mode is on by default. It can be disabled with the -U
303 option, below.
304 -U
306 --disable-deterministic-archives
307 Do not operate in deterministic mode. This is the inverse of the
308 -D option, above: when copying archive members and writing the
309 archive index, use their actual UID, GID, timestamp, and file mode
310 values.
311 This is the default unless binutils was configured with
313 --enable-deterministic-archives.
314 --debugging
316 Convert debugging information, if possible. This is not the
317 default because only certain debugging formats are supported, and
318 the conversion process can be time consuming.
319 --gap-fill val
321 Fill gaps between sections with val. This operation applies to the
322 load address (LMA) of the sections. It is done by increasing the
323 size of the section with the lower address, and filling in the
324 extra space created with val.
325 --pad-to address
327 Pad the output file up to the load address address. This is done
328 by increasing the size of the last section. The extra space is
329 filled in with the value specified by --gap-fill (default zero).
330 --set-start val
332 Set the start address of the new file to val. Not all object file
333 formats support setting the start address.
334 --change-start incr
336 --adjust-start incr
337 Change the start address by adding incr. Not all object file
338 formats support setting the start address.
339 --change-addresses incr
341 --adjust-vma incr
342 Change the VMA and LMA addresses of all sections, as well as the
343 start address, by adding incr. Some object file formats do not
344 permit section addresses to be changed arbitrarily. Note that this
345 does not relocate the sections; if the program expects sections to
346 be loaded at a certain address, and this option is used to change
347 the sections such that they are loaded at a different address, the
348 program may fail.
349 --change-section-address sectionpattern{=,+,-}val
351 --adjust-section-vma sectionpattern{=,+,-}val
352 Set or change both the VMA address and the LMA address of any
353 section matching sectionpattern. If = is used, the section address
354 is set to val. Otherwise, val is added to or subtracted from the
355 section address. See the comments under --change-addresses, above.
356 If sectionpattern does not match any sections in the input file, a
357 warning will be issued, unless --no-change-warnings is used.
358 --change-section-lma sectionpattern{=,+,-}val
360 Set or change the LMA address of any sections matching
361 sectionpattern. The LMA address is the address where the section
362 will be loaded into memory at program load time. Normally this is
363 the same as the VMA address, which is the address of the section at
364 program run time, but on some systems, especially those where a
365 program is held in ROM, the two can be different. If = is used,
366 the section address is set to val. Otherwise, val is added to or
367 subtracted from the section address. See the comments under
368 --change-addresses, above. If sectionpattern does not match any
369 sections in the input file, a warning will be issued, unless
370 --no-change-warnings is used.
371 --change-section-vma sectionpattern{=,+,-}val
373 Set or change the VMA address of any section matching
374 sectionpattern. The VMA address is the address where the section
375 will be located once the program has started executing. Normally
376 this is the same as the LMA address, which is the address where the
377 section will be loaded into memory, but on some systems, especially
378 those where a program is held in ROM, the two can be different. If
379 = is used, the section address is set to val. Otherwise, val is
380 added to or subtracted from the section address. See the comments
381 under --change-addresses, above. If sectionpattern does not match
382 any sections in the input file, a warning will be issued, unless
383 --no-change-warnings is used.
384 --change-warnings
386 --adjust-warnings
387 If --change-section-address or --change-section-lma or
388 --change-section-vma is used, and the section pattern does not
389 match any sections, issue a warning. This is the default.
390 --no-change-warnings
392 --no-adjust-warnings
393 Do not issue a warning if --change-section-address or
394 --adjust-section-lma or --adjust-section-vma is used, even if the
395 section pattern does not match any sections.
396 --set-section-flags sectionpattern=flags
398 Set the flags for any sections matching sectionpattern. The flags
399 argument is a comma separated string of flag names. The recognized
400 names are alloc, contents, load, noload, readonly, code, data, rom,
401 share, and debug. You can set the contents flag for a section
402 which does not have contents, but it is not meaningful to clear the
403 contents flag of a section which does have contents--just remove
404 the section instead. Not all flags are meaningful for all object
405 file formats.
406 --add-section sectionname=filename
408 Add a new section named sectionname while copying the file. The
409 contents of the new section are taken from the file filename. The
410 size of the section will be the size of the file. This option only
411 works on file formats which can support sections with arbitrary
412 names. Note - it may be necessary to use the --set-section-flags
413 option to set the attributes of the newly created section.
414 --dump-section sectionname=filename
416 Place the contents of section named sectionname into the file
417 filename, overwriting any contents that may have been there
418 previously. This option is the inverse of --add-section. This
419 option is similar to the --only-section option except that it does
420 not create a formatted file, it just dumps the contents as raw
421 binary data, without applying any relocations. The option can be
422 specified more than once.
423 --update-section sectionname=filename
425 Replace the existing contents of a section named sectionname with
426 the contents of file filename. The size of the section will be
427 adjusted to the size of the file. The section flags for
428 sectionname will be unchanged. For ELF format files the section to
429 segment mapping will also remain unchanged, something which is not
430 possible using --remove-section followed by --add-section. The
431 option can be specified more than once.
432 Note - it is possible to use --rename-section and --update-section
434 to both update and rename a section from one command line. In this
435 case, pass the original section name to --update-section, and the
436 original and new section names to --rename-section.
437 --add-symbol name=[section:]value[,flags]
439 Add a new symbol named name while copying the file. This option
440 may be specified multiple times. If the section is given, the
441 symbol will be associated with and relative to that section,
442 otherwise it will be an ABS symbol. Specifying an undefined
443 section will result in a fatal error. There is no check for the
444 value, it will be taken as specified. Symbol flags can be
445 specified and not all flags will be meaningful for all object file
446 formats. By default, the symbol will be global. The special flag
447 'before=othersym' will insert the new symbol in front of the
448 specified othersym, otherwise the symbol(s) will be added at the
449 end of the symbol table in the order they appear.
450 --rename-section oldname=newname[,flags]
452 Rename a section from oldname to newname, optionally changing the
453 section's flags to flags in the process. This has the advantage
454 over usng a linker script to perform the rename in that the output
455 stays as an object file and does not become a linked executable.
456 This option is particularly helpful when the input format is
458 binary, since this will always create a section called .data. If
459 for example, you wanted instead to create a section called .rodata
460 containing binary data you could use the following command line to
461 achieve it:
462 objcopy -I binary -O <output_format> -B <architecture> \
464 --rename-section .data=.rodata,alloc,load,readonly,data,contents \
465 <input_binary_file> <output_object_file>
466 --long-section-names {enable,disable,keep}
468 Controls the handling of long section names when processing "COFF"
469 and "PE-COFF" object formats. The default behaviour, keep, is to
470 preserve long section names if any are present in the input file.
471 The enable and disable options forcibly enable or disable the use
472 of long section names in the output object; when disable is in
473 effect, any long section names in the input object will be
474 truncated. The enable option will only emit long section names if
475 any are present in the inputs; this is mostly the same as keep, but
476 it is left undefined whether the enable option might force the
477 creation of an empty string table in the output file.
478 --change-leading-char
480 Some object file formats use special characters at the start of
481 symbols. The most common such character is underscore, which
482 compilers often add before every symbol. This option tells objcopy
483 to change the leading character of every symbol when it converts
484 between object file formats. If the object file formats use the
485 same leading character, this option has no effect. Otherwise, it
486 will add a character, or remove a character, or change a character,
487 as appropriate.
488 --remove-leading-char
490 If the first character of a global symbol is a special symbol
491 leading character used by the object file format, remove the
492 character. The most common symbol leading character is underscore.
493 This option will remove a leading underscore from all global
494 symbols. This can be useful if you want to link together objects
495 of different file formats with different conventions for symbol
496 names. This is different from --change-leading-char because it
497 always changes the symbol name when appropriate, regardless of the
498 object file format of the output file.
499 --reverse-bytes=num
501 Reverse the bytes in a section with output contents. A section
502 length must be evenly divisible by the value given in order for the
503 swap to be able to take place. Reversing takes place before the
504 interleaving is performed.
505 This option is used typically in generating ROM images for
507 problematic target systems. For example, on some target boards,
508 the 32-bit words fetched from 8-bit ROMs are re-assembled in
509 little-endian byte order regardless of the CPU byte order.
510 Depending on the programming model, the endianness of the ROM may
511 need to be modified.
512 Consider a simple file with a section containing the following
514 eight bytes: 12345678.
515 Using --reverse-bytes=2 for the above example, the bytes in the
517 output file would be ordered 21436587.
518 Using --reverse-bytes=4 for the above example, the bytes in the
520 output file would be ordered 43218765.
521 By using --reverse-bytes=2 for the above example, followed by
523 --reverse-bytes=4 on the output file, the bytes in the second
524 output file would be ordered 34127856.
525 --srec-len=ival
527 Meaningful only for srec output. Set the maximum length of the
528 Srecords being produced to ival. This length covers both address,
529 data and crc fields.
530 --srec-forceS3
532 Meaningful only for srec output. Avoid generation of S1/S2
533 records, creating S3-only record format.
534 --redefine-sym old=new
536 Change the name of a symbol old, to new. This can be useful when
537 one is trying link two things together for which you have no
538 source, and there are name collisions.
539 --redefine-syms=filename
541 Apply --redefine-sym to each symbol pair "old new" listed in the
542 file filename. filename is simply a flat file, with one symbol
543 pair per line. Line comments may be introduced by the hash
544 character. This option may be given more than once.
545 --weaken
547 Change all global symbols in the file to be weak. This can be
548 useful when building an object which will be linked against other
549 objects using the -R option to the linker. This option is only
550 effective when using an object file format which supports weak
551 symbols.
552 --keep-symbols=filename
554 Apply --keep-symbol option to each symbol listed in the file
555 filename. filename is simply a flat file, with one symbol name per
556 line. Line comments may be introduced by the hash character. This
557 option may be given more than once.
558 --strip-symbols=filename
560 Apply --strip-symbol option to each symbol listed in the file
561 filename. filename is simply a flat file, with one symbol name per
562 line. Line comments may be introduced by the hash character. This
563 option may be given more than once.
564 --strip-unneeded-symbols=filename
566 Apply --strip-unneeded-symbol option to each symbol listed in the
567 file filename. filename is simply a flat file, with one symbol
568 name per line. Line comments may be introduced by the hash
569 character. This option may be given more than once.
570 --keep-global-symbols=filename
572 Apply --keep-global-symbol option to each symbol listed in the file
573 filename. filename is simply a flat file, with one symbol name per
574 line. Line comments may be introduced by the hash character. This
575 option may be given more than once.
576 --localize-symbols=filename
578 Apply --localize-symbol option to each symbol listed in the file
579 filename. filename is simply a flat file, with one symbol name per
580 line. Line comments may be introduced by the hash character. This
581 option may be given more than once.
582 --globalize-symbols=filename
584 Apply --globalize-symbol option to each symbol listed in the file
585 filename. filename is simply a flat file, with one symbol name per
586 line. Line comments may be introduced by the hash character. This
587 option may be given more than once.
588 --weaken-symbols=filename
590 Apply --weaken-symbol option to each symbol listed in the file
591 filename. filename is simply a flat file, with one symbol name per
592 line. Line comments may be introduced by the hash character. This
593 option may be given more than once.
594 --alt-machine-code=index
596 If the output architecture has alternate machine codes, use the
597 indexth code instead of the default one. This is useful in case a
598 machine is assigned an official code and the tool-chain adopts the
599 new code, but other applications still depend on the original code
600 being used. For ELF based architectures if the index alternative
601 does not exist then the value is treated as an absolute number to
602 be stored in the e_machine field of the ELF header.
603 --writable-text
605 Mark the output text as writable. This option isn't meaningful for
606 all object file formats.
607 --readonly-text
609 Make the output text write protected. This option isn't meaningful
610 for all object file formats.
611 --pure
613 Mark the output file as demand paged. This option isn't meaningful
614 for all object file formats.
615 --impure
617 Mark the output file as impure. This option isn't meaningful for
618 all object file formats.
619 --prefix-symbols=string
621 Prefix all symbols in the output file with string.
622 --prefix-sections=string
624 Prefix all section names in the output file with string.
625 --prefix-alloc-sections=string
627 Prefix all the names of all allocated sections in the output file
628 with string.
629 --add-gnu-debuglink=path-to-file
631 Creates a .gnu_debuglink section which contains a reference to
632 path-to-file and adds it to the output file. Note: the file at
633 path-to-file must exist. Part of the process of adding the
634 .gnu_debuglink section involves embedding a checksum of the
635 contents of the debug info file into the section.
636 If the debug info file is built in one location but it is going to
638 be installed at a later time into a different location then do not
639 use the path to the installed location. The --add-gnu-debuglink
640 option will fail because the installed file does not exist yet.
641 Instead put the debug info file in the current directory and use
642 the --add-gnu-debuglink option without any directory components,
643 like this:
644 objcopy --add-gnu-debuglink=foo.debug
646 At debug time the debugger will attempt to look for the separate
648 debug info file in a set of known locations. The exact set of
649 these locations varies depending upon the distribution being used,
650 but it typically includes:
651 "* The same directory as the executable."
653 "* A sub-directory of the directory containing the executable"
654 called .debug
655 "* A global debug directory such as /usr/lib/debug."
657 As long as the debug info file has been installed into one of these
659 locations before the debugger is run everything should work
660 correctly.
661 --keep-file-symbols
663 When stripping a file, perhaps with --strip-debug or
664 --strip-unneeded, retain any symbols specifying source file names,
665 which would otherwise get stripped.
666 --only-keep-debug
668 Strip a file, removing contents of any sections that would not be
669 stripped by --strip-debug and leaving the debugging sections
670 intact. In ELF files, this preserves all note sections in the
671 output.
672 Note - the section headers of the stripped sections are preserved,
674 including their sizes, but the contents of the section are
675 discarded. The section headers are preserved so that other tools
676 can match up the debuginfo file with the real executable, even if
677 that executable has been relocated to a different address space.
678 The intention is that this option will be used in conjunction with
680 --add-gnu-debuglink to create a two part executable. One a
681 stripped binary which will occupy less space in RAM and in a
682 distribution and the second a debugging information file which is
683 only needed if debugging abilities are required. The suggested
684 procedure to create these files is as follows:
685 1.<Link the executable as normal. Assuming that is is called>
687 "foo" then...
688 1.<Run "objcopy --only-keep-debug foo foo.dbg" to>
690 create a file containing the debugging info.
691 1.<Run "objcopy --strip-debug foo" to create a>
693 stripped executable.
694 1.<Run "objcopy --add-gnu-debuglink=foo.dbg foo">
696 to add a link to the debugging info into the stripped
697 executable.
698 Note---the choice of ".dbg" as an extension for the debug info file
700 is arbitrary. Also the "--only-keep-debug" step is optional. You
701 could instead do this:
702 1.<Link the executable as normal.>
704 1.<Copy "foo" to "foo.full">
705 1.<Run "objcopy --strip-debug foo">
706 1.<Run "objcopy --add-gnu-debuglink=foo.full foo">
707 i.e., the file pointed to by the --add-gnu-debuglink can be the
709 full executable. It does not have to be a file created by the
710 --only-keep-debug switch.
711 Note---this switch is only intended for use on fully linked files.
713 It does not make sense to use it on object files where the
714 debugging information may be incomplete. Besides the gnu_debuglink
715 feature currently only supports the presence of one filename
716 containing debugging information, not multiple filenames on a one-
717 per-object-file basis.
718 --strip-dwo
720 Remove the contents of all DWARF .dwo sections, leaving the
721 remaining debugging sections and all symbols intact. This option
722 is intended for use by the compiler as part of the -gsplit-dwarf
723 option, which splits debug information between the .o file and a
724 separate .dwo file. The compiler generates all debug information
725 in the same file, then uses the --extract-dwo option to copy the
726 .dwo sections to the .dwo file, then the --strip-dwo option to
727 remove those sections from the original .o file.
728 --extract-dwo
730 Extract the contents of all DWARF .dwo sections. See the
731 --strip-dwo option for more information.
732 --file-alignment num
734 Specify the file alignment. Sections in the file will always begin
735 at file offsets which are multiples of this number. This defaults
736 to 512. [This option is specific to PE targets.]
737 --heap reserve
739 --heap reserve,commit
740 Specify the number of bytes of memory to reserve (and optionally
741 commit) to be used as heap for this program. [This option is
742 specific to PE targets.]
743 --image-base value
745 Use value as the base address of your program or dll. This is the
746 lowest memory location that will be used when your program or dll
747 is loaded. To reduce the need to relocate and improve performance
748 of your dlls, each should have a unique base address and not
749 overlap any other dlls. The default is 0x400000 for executables,
750 and 0x10000000 for dlls. [This option is specific to PE targets.]
751 --section-alignment num
753 Sets the section alignment. Sections in memory will always begin
754 at addresses which are a multiple of this number. Defaults to
755 0x1000. [This option is specific to PE targets.]
756 --stack reserve
758 --stack reserve,commit
759 Specify the number of bytes of memory to reserve (and optionally
760 commit) to be used as stack for this program. [This option is
761 specific to PE targets.]
762 --subsystem which
764 --subsystem which:major
765 --subsystem which:major.minor
766 Specifies the subsystem under which your program will execute. The
767 legal values for which are "native", "windows", "console", "posix",
768 "efi-app", "efi-bsd", "efi-rtd", "sal-rtd", and "xbox". You may
769 optionally set the subsystem version also. Numeric values are also
770 accepted for which. [This option is specific to PE targets.]
771 --extract-symbol
773 Keep the file's section flags and symbols but remove all section
774 data. Specifically, the option:
775 *<removes the contents of all sections;>
777 *<sets the size of every section to zero; and>
778 *<sets the file's start address to zero.>
779 This option is used to build a .sym file for a VxWorks kernel. It
781 can also be a useful way of reducing the size of a --just-symbols
782 linker input file.
783 --compress-debug-sections
785 Compress DWARF debug sections using zlib with SHF_COMPRESSED from
786 the ELF ABI. Note - if compression would actually make a section
787 larger, then it is not compressed.
788 --compress-debug-sections=none
790 --compress-debug-sections=zlib
791 --compress-debug-sections=zlib-gnu
792 --compress-debug-sections=zlib-gabi
793 For ELF files, these options control how DWARF debug sections are
794 compressed. --compress-debug-sections=none is equivalent to
795 --nocompress-debug-sections. --compress-debug-sections=zlib and
796 --compress-debug-sections=zlib-gabi are equivalent to
797 --compress-debug-sections. --compress-debug-sections=zlib-gnu
798 compresses DWARF debug sections using zlib. The debug sections are
799 renamed to begin with .zdebug instead of .debug. Note - if
800 compression would actually make a section larger, then it is not
801 compressed nor renamed.
802 --decompress-debug-sections
804 Decompress DWARF debug sections using zlib. The original section
805 names of the compressed sections are restored.
806 -V
808 --version
809 Show the version number of objcopy.
810 -v
812 --verbose
813 Verbose output: list all object files modified. In the case of
814 archives, objcopy -V lists all members of the archive.
815 --help
817 Show a summary of the options to objcopy.
818 --info
820 Display a list showing all architectures and object formats
821 available.
822 @file
824 Read command-line options from file. The options read are inserted
825 in place of the original @file option. If file does not exist, or
826 cannot be read, then the option will be treated literally, and not
827 removed.
828 Options in file are separated by whitespace. A whitespace
830 character may be included in an option by surrounding the entire
831 option in either single or double quotes. Any character (including
832 a backslash) may be included by prefixing the character to be
833 included with a backslash. The file may itself contain additional
834 @file options; any such options will be processed recursively.
835
837 ld(1), objdump(1), and the Info entries for binutils.
838
840 Copyright (c) 1991-2015 Free Software Foundation, Inc.
841 Permission is granted to copy, distribute and/or modify this document
843 under the terms of the GNU Free Documentation License, Version 1.3 or
844 any later version published by the Free Software Foundation; with no
845 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
846 Texts. A copy of the license is included in the section entitled "GNU
847 Free Documentation License".
848binutils-2.26 2016-01-25 OBJCOPY(1)