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 [--elf-stt-common=val]
87 [-v|--verbose]
88 [-V|--version]
89 [--help] [--info]
90 infile [outfile]
91
93 The GNU objcopy utility copies the contents of an object file to
94 another. objcopy uses the GNU BFD Library to read and write the object
95 files. It can write the destination object file in a format different
96 from that of the source object file. The exact behavior of objcopy is
97 controlled by command-line options. Note that objcopy should be able
98 to copy a fully linked file between any two formats. However, copying a
99 relocatable object file between any two formats may not work as
100 expected.
101 objcopy creates temporary files to do its translations and deletes them
103 afterward. objcopy uses BFD to do all its translation work; it has
104 access to all the formats described in BFD and thus is able to
105 recognize most formats without being told explicitly.
106 objcopy can be used to generate S-records by using an output target of
108 srec (e.g., use -O srec).
109 objcopy can be used to generate a raw binary file by using an output
111 target of binary (e.g., use -O binary). When objcopy generates a raw
112 binary file, it will essentially produce a memory dump of the contents
113 of the input object file. All symbols and relocation information will
114 be discarded. The memory dump will start at the load address of the
115 lowest section copied into the output file.
116 When generating an S-record or a raw binary file, it may be helpful to
118 use -S to remove sections containing debugging information. In some
119 cases -R will be useful to remove sections which contain information
120 that is not needed by the binary file.
121 Note---objcopy is not able to change the endianness of its input files.
123 If the input format has an endianness (some formats do not), objcopy
124 can only copy the inputs into file formats that have the same
125 endianness or which have no endianness (e.g., srec). (However, see the
126 --reverse-bytes option.)
127
129 infile
130 outfile
131 The input and output files, respectively. If you do not specify
132 outfile, objcopy creates a temporary file and destructively renames
133 the result with the name of infile.
134 -I bfdname
136 --input-target=bfdname
137 Consider the source file's object format to be bfdname, rather than
138 attempting to deduce it.
139 -O bfdname
141 --output-target=bfdname
142 Write the output file using the object format bfdname.
143 -F bfdname
145 --target=bfdname
146 Use bfdname as the object format for both the input and the output
147 file; i.e., simply transfer data from source to destination with no
148 translation.
149 -B bfdarch
151 --binary-architecture=bfdarch
152 Useful when transforming a architecture-less input file into an
153 object file. In this case the output architecture can be set to
154 bfdarch. This option will be ignored if the input file has a known
155 bfdarch. You can access this binary data inside a program by
156 referencing the special symbols that are created by the conversion
157 process. These symbols are called _binary_objfile_start,
158 _binary_objfile_end and _binary_objfile_size. e.g. you can
159 transform a picture file into an object file and then access it in
160 your code using these symbols.
161 -j sectionpattern
163 --only-section=sectionpattern
164 Copy only the indicated sections from the input file to the output
165 file. This option may be given more than once. Note that using
166 this option inappropriately may make the output file unusable.
167 Wildcard characters are accepted in sectionpattern.
168 -R sectionpattern
170 --remove-section=sectionpattern
171 Remove any section matching sectionpattern from the output file.
172 This option may be given more than once. Note that using this
173 option inappropriately may make the output file unusable. Wildcard
174 characters are accepted in sectionpattern. Using both the -j and
175 -R options together results in undefined behaviour.
176 -S
178 --strip-all
179 Do not copy relocation and symbol information from the source file.
180 -g
182 --strip-debug
183 Do not copy debugging symbols or sections from the source file.
184 --strip-unneeded
186 Strip all symbols that are not needed for relocation processing.
187 -K symbolname
189 --keep-symbol=symbolname
190 When stripping symbols, keep symbol symbolname even if it would
191 normally be stripped. This option may be given more than once.
192 -N symbolname
194 --strip-symbol=symbolname
195 Do not copy symbol symbolname from the source file. This option
196 may be given more than once.
197 --strip-unneeded-symbol=symbolname
199 Do not copy symbol symbolname from the source file unless it is
200 needed by a relocation. This option may be given more than once.
201 -G symbolname
203 --keep-global-symbol=symbolname
204 Keep only symbol symbolname global. Make all other symbols local
205 to the file, so that they are not visible externally. This option
206 may be given more than once.
207 --localize-hidden
209 In an ELF object, mark all symbols that have hidden or internal
210 visibility as local. This option applies on top of symbol-specific
211 localization options such as -L.
212 -L symbolname
214 --localize-symbol=symbolname
215 Make symbol symbolname local to the file, so that it is not visible
216 externally. This option may be given more than once.
217 -W symbolname
219 --weaken-symbol=symbolname
220 Make symbol symbolname weak. This option may be given more than
221 once.
222 --globalize-symbol=symbolname
224 Give symbol symbolname global scoping so that it is visible outside
225 of the file in which it is defined. This option may be given more
226 than once.
227 -w
229 --wildcard
230 Permit regular expressions in symbolnames used in other command
231 line options. The question mark (?), asterisk (*), backslash (\)
232 and square brackets ([]) operators can be used anywhere in the
233 symbol name. If the first character of the symbol name is the
234 exclamation point (!) then the sense of the switch is reversed for
235 that symbol. For example:
236 -w -W !foo -W fo*
238 would cause objcopy to weaken all symbols that start with "fo"
240 except for the symbol "foo".
241 -x
243 --discard-all
244 Do not copy non-global symbols from the source file.
245 -X
247 --discard-locals
248 Do not copy compiler-generated local symbols. (These usually start
249 with L or ..)
250 -b byte
252 --byte=byte
253 If interleaving has been enabled via the --interleave option then
254 start the range of bytes to keep at the byteth byte. byte can be
255 in the range from 0 to breadth-1, where breadth is the value given
256 by the --interleave option.
257 -i [breadth]
259 --interleave[=breadth]
260 Only copy a range out of every breadth bytes. (Header data is not
261 affected). Select which byte in the range begins the copy with the
262 --byte option. Select the width of the range with the
263 --interleave-width option.
264 This option is useful for creating files to program ROM. It is
266 typically used with an "srec" output target. Note that objcopy
267 will complain if you do not specify the --byte option as well.
268 The default interleave breadth is 4, so with --byte set to 0,
270 objcopy would copy the first byte out of every four bytes from the
271 input to the output.
272 --interleave-width=width
274 When used with the --interleave option, copy width bytes at a time.
275 The start of the range of bytes to be copied is set by the --byte
276 option, and the extent of the range is set with the --interleave
277 option.
278 The default value for this option is 1. The value of width plus
280 the byte value set by the --byte option must not exceed the
281 interleave breadth set by the --interleave option.
282 This option can be used to create images for two 16-bit flashes
284 interleaved in a 32-bit bus by passing -b 0 -i 4
285 --interleave-width=2 and -b 2 -i 4 --interleave-width=2 to two
286 objcopy commands. If the input was '12345678' then the outputs
287 would be '1256' and '3478' respectively.
288 -p
290 --preserve-dates
291 Set the access and modification dates of the output file to be the
292 same as those of the input file.
293 -D
295 --enable-deterministic-archives
296 Operate in deterministic mode. When copying archive members and
297 writing the archive index, use zero for UIDs, GIDs, timestamps, and
298 use consistent file modes for all files.
299 If binutils was configured with --enable-deterministic-archives,
301 then this mode is on by default. It can be disabled with the -U
302 option, below.
303 -U
305 --disable-deterministic-archives
306 Do not operate in deterministic mode. This is the inverse of the
307 -D option, above: when copying archive members and writing the
308 archive index, use their actual UID, GID, timestamp, and file mode
309 values.
310 This is the default unless binutils was configured with
312 --enable-deterministic-archives.
313 --debugging
315 Convert debugging information, if possible. This is not the
316 default because only certain debugging formats are supported, and
317 the conversion process can be time consuming.
318 --gap-fill val
320 Fill gaps between sections with val. This operation applies to the
321 load address (LMA) of the sections. It is done by increasing the
322 size of the section with the lower address, and filling in the
323 extra space created with val.
324 --pad-to address
326 Pad the output file up to the load address address. This is done
327 by increasing the size of the last section. The extra space is
328 filled in with the value specified by --gap-fill (default zero).
329 --set-start val
331 Set the start address of the new file to val. Not all object file
332 formats support setting the start address.
333 --change-start incr
335 --adjust-start incr
336 Change the start address by adding incr. Not all object file
337 formats support setting the start address.
338 --change-addresses incr
340 --adjust-vma incr
341 Change the VMA and LMA addresses of all sections, as well as the
342 start address, by adding incr. Some object file formats do not
343 permit section addresses to be changed arbitrarily. Note that this
344 does not relocate the sections; if the program expects sections to
345 be loaded at a certain address, and this option is used to change
346 the sections such that they are loaded at a different address, the
347 program may fail.
348 --change-section-address sectionpattern{=,+,-}val
350 --adjust-section-vma sectionpattern{=,+,-}val
351 Set or change both the VMA address and the LMA address of any
352 section matching sectionpattern. If = is used, the section address
353 is set to val. Otherwise, val is added to or subtracted from the
354 section address. See the comments under --change-addresses, above.
355 If sectionpattern does not match any sections in the input file, a
356 warning will be issued, unless --no-change-warnings is used.
357 --change-section-lma sectionpattern{=,+,-}val
359 Set or change the LMA address of any sections matching
360 sectionpattern. The LMA address is the address where the section
361 will be loaded into memory at program load time. Normally this is
362 the same as the VMA address, which is the address of the section at
363 program run time, but on some systems, especially those where a
364 program is held in ROM, the two can be different. If = is used,
365 the section address is set to val. Otherwise, val is added to or
366 subtracted from the section address. See the comments under
367 --change-addresses, above. If sectionpattern does not match any
368 sections in the input file, a warning will be issued, unless
369 --no-change-warnings is used.
370 --change-section-vma sectionpattern{=,+,-}val
372 Set or change the VMA address of any section matching
373 sectionpattern. The VMA address is the address where the section
374 will be located once the program has started executing. Normally
375 this is the same as the LMA address, which is the address where the
376 section will be loaded into memory, but on some systems, especially
377 those where a program is held in ROM, the two can be different. If
378 = is used, the section address is set to val. Otherwise, val is
379 added to or subtracted from the section address. See the comments
380 under --change-addresses, above. If sectionpattern does not match
381 any sections in the input file, a warning will be issued, unless
382 --no-change-warnings is used.
383 --change-warnings
385 --adjust-warnings
386 If --change-section-address or --change-section-lma or
387 --change-section-vma is used, and the section pattern does not
388 match any sections, issue a warning. This is the default.
389 --no-change-warnings
391 --no-adjust-warnings
392 Do not issue a warning if --change-section-address or
393 --adjust-section-lma or --adjust-section-vma is used, even if the
394 section pattern does not match any sections.
395 --set-section-flags sectionpattern=flags
397 Set the flags for any sections matching sectionpattern. The flags
398 argument is a comma separated string of flag names. The recognized
399 names are alloc, contents, load, noload, readonly, code, data, rom,
400 share, and debug. You can set the contents flag for a section
401 which does not have contents, but it is not meaningful to clear the
402 contents flag of a section which does have contents--just remove
403 the section instead. Not all flags are meaningful for all object
404 file formats.
405 --add-section sectionname=filename
407 Add a new section named sectionname while copying the file. The
408 contents of the new section are taken from the file filename. The
409 size of the section will be the size of the file. This option only
410 works on file formats which can support sections with arbitrary
411 names. Note - it may be necessary to use the --set-section-flags
412 option to set the attributes of the newly created section.
413 --dump-section sectionname=filename
415 Place the contents of section named sectionname into the file
416 filename, overwriting any contents that may have been there
417 previously. This option is the inverse of --add-section. This
418 option is similar to the --only-section option except that it does
419 not create a formatted file, it just dumps the contents as raw
420 binary data, without applying any relocations. The option can be
421 specified more than once.
422 --update-section sectionname=filename
424 Replace the existing contents of a section named sectionname with
425 the contents of file filename. The size of the section will be
426 adjusted to the size of the file. The section flags for
427 sectionname will be unchanged. For ELF format files the section to
428 segment mapping will also remain unchanged, something which is not
429 possible using --remove-section followed by --add-section. The
430 option can be specified more than once.
431 Note - it is possible to use --rename-section and --update-section
433 to both update and rename a section from one command line. In this
434 case, pass the original section name to --update-section, and the
435 original and new section names to --rename-section.
436 --add-symbol name=[section:]value[,flags]
438 Add a new symbol named name while copying the file. This option
439 may be specified multiple times. If the section is given, the
440 symbol will be associated with and relative to that section,
441 otherwise it will be an ABS symbol. Specifying an undefined
442 section will result in a fatal error. There is no check for the
443 value, it will be taken as specified. Symbol flags can be
444 specified and not all flags will be meaningful for all object file
445 formats. By default, the symbol will be global. The special flag
446 'before=othersym' will insert the new symbol in front of the
447 specified othersym, otherwise the symbol(s) will be added at the
448 end of the symbol table in the order they appear.
449 --rename-section oldname=newname[,flags]
451 Rename a section from oldname to newname, optionally changing the
452 section's flags to flags in the process. This has the advantage
453 over usng a linker script to perform the rename in that the output
454 stays as an object file and does not become a linked executable.
455 This option is particularly helpful when the input format is
457 binary, since this will always create a section called .data. If
458 for example, you wanted instead to create a section called .rodata
459 containing binary data you could use the following command line to
460 achieve it:
461 objcopy -I binary -O <output_format> -B <architecture> \
463 --rename-section .data=.rodata,alloc,load,readonly,data,contents \
464 <input_binary_file> <output_object_file>
465 --long-section-names {enable,disable,keep}
467 Controls the handling of long section names when processing "COFF"
468 and "PE-COFF" object formats. The default behaviour, keep, is to
469 preserve long section names if any are present in the input file.
470 The enable and disable options forcibly enable or disable the use
471 of long section names in the output object; when disable is in
472 effect, any long section names in the input object will be
473 truncated. The enable option will only emit long section names if
474 any are present in the inputs; this is mostly the same as keep, but
475 it is left undefined whether the enable option might force the
476 creation of an empty string table in the output file.
477 --change-leading-char
479 Some object file formats use special characters at the start of
480 symbols. The most common such character is underscore, which
481 compilers often add before every symbol. This option tells objcopy
482 to change the leading character of every symbol when it converts
483 between object file formats. If the object file formats use the
484 same leading character, this option has no effect. Otherwise, it
485 will add a character, or remove a character, or change a character,
486 as appropriate.
487 --remove-leading-char
489 If the first character of a global symbol is a special symbol
490 leading character used by the object file format, remove the
491 character. The most common symbol leading character is underscore.
492 This option will remove a leading underscore from all global
493 symbols. This can be useful if you want to link together objects
494 of different file formats with different conventions for symbol
495 names. This is different from --change-leading-char because it
496 always changes the symbol name when appropriate, regardless of the
497 object file format of the output file.
498 --reverse-bytes=num
500 Reverse the bytes in a section with output contents. A section
501 length must be evenly divisible by the value given in order for the
502 swap to be able to take place. Reversing takes place before the
503 interleaving is performed.
504 This option is used typically in generating ROM images for
506 problematic target systems. For example, on some target boards,
507 the 32-bit words fetched from 8-bit ROMs are re-assembled in
508 little-endian byte order regardless of the CPU byte order.
509 Depending on the programming model, the endianness of the ROM may
510 need to be modified.
511 Consider a simple file with a section containing the following
513 eight bytes: 12345678.
514 Using --reverse-bytes=2 for the above example, the bytes in the
516 output file would be ordered 21436587.
517 Using --reverse-bytes=4 for the above example, the bytes in the
519 output file would be ordered 43218765.
520 By using --reverse-bytes=2 for the above example, followed by
522 --reverse-bytes=4 on the output file, the bytes in the second
523 output file would be ordered 34127856.
524 --srec-len=ival
526 Meaningful only for srec output. Set the maximum length of the
527 Srecords being produced to ival. This length covers both address,
528 data and crc fields.
529 --srec-forceS3
531 Meaningful only for srec output. Avoid generation of S1/S2
532 records, creating S3-only record format.
533 --redefine-sym old=new
535 Change the name of a symbol old, to new. This can be useful when
536 one is trying link two things together for which you have no
537 source, and there are name collisions.
538 --redefine-syms=filename
540 Apply --redefine-sym to each symbol pair "old new" listed in the
541 file filename. filename is simply a flat file, with one symbol
542 pair per line. Line comments may be introduced by the hash
543 character. This option may be given more than once.
544 --weaken
546 Change all global symbols in the file to be weak. This can be
547 useful when building an object which will be linked against other
548 objects using the -R option to the linker. This option is only
549 effective when using an object file format which supports weak
550 symbols.
551 --keep-symbols=filename
553 Apply --keep-symbol option to each symbol listed in the file
554 filename. filename is simply a flat file, with one symbol name per
555 line. Line comments may be introduced by the hash character. This
556 option may be given more than once.
557 --strip-symbols=filename
559 Apply --strip-symbol option to each symbol listed in the file
560 filename. filename is simply a flat file, with one symbol name per
561 line. Line comments may be introduced by the hash character. This
562 option may be given more than once.
563 --strip-unneeded-symbols=filename
565 Apply --strip-unneeded-symbol option to each symbol listed in the
566 file filename. filename is simply a flat file, with one symbol
567 name per line. Line comments may be introduced by the hash
568 character. This option may be given more than once.
569 --keep-global-symbols=filename
571 Apply --keep-global-symbol option to each symbol listed in the file
572 filename. filename is simply a flat file, with one symbol name per
573 line. Line comments may be introduced by the hash character. This
574 option may be given more than once.
575 --localize-symbols=filename
577 Apply --localize-symbol option to each symbol listed in the file
578 filename. filename is simply a flat file, with one symbol name per
579 line. Line comments may be introduced by the hash character. This
580 option may be given more than once.
581 --globalize-symbols=filename
583 Apply --globalize-symbol option to each symbol listed in the file
584 filename. filename is simply a flat file, with one symbol name per
585 line. Line comments may be introduced by the hash character. This
586 option may be given more than once.
587 --weaken-symbols=filename
589 Apply --weaken-symbol option to each symbol listed in the file
590 filename. filename is simply a flat file, with one symbol name per
591 line. Line comments may be introduced by the hash character. This
592 option may be given more than once.
593 --alt-machine-code=index
595 If the output architecture has alternate machine codes, use the
596 indexth code instead of the default one. This is useful in case a
597 machine is assigned an official code and the tool-chain adopts the
598 new code, but other applications still depend on the original code
599 being used. For ELF based architectures if the index alternative
600 does not exist then the value is treated as an absolute number to
601 be stored in the e_machine field of the ELF header.
602 --writable-text
604 Mark the output text as writable. This option isn't meaningful for
605 all object file formats.
606 --readonly-text
608 Make the output text write protected. This option isn't meaningful
609 for all object file formats.
610 --pure
612 Mark the output file as demand paged. This option isn't meaningful
613 for all object file formats.
614 --impure
616 Mark the output file as impure. This option isn't meaningful for
617 all object file formats.
618 --prefix-symbols=string
620 Prefix all symbols in the output file with string.
621 --prefix-sections=string
623 Prefix all section names in the output file with string.
624 --prefix-alloc-sections=string
626 Prefix all the names of all allocated sections in the output file
627 with string.
628 --add-gnu-debuglink=path-to-file
630 Creates a .gnu_debuglink section which contains a reference to
631 path-to-file and adds it to the output file. Note: the file at
632 path-to-file must exist. Part of the process of adding the
633 .gnu_debuglink section involves embedding a checksum of the
634 contents of the debug info file into the section.
635 If the debug info file is built in one location but it is going to
637 be installed at a later time into a different location then do not
638 use the path to the installed location. The --add-gnu-debuglink
639 option will fail because the installed file does not exist yet.
640 Instead put the debug info file in the current directory and use
641 the --add-gnu-debuglink option without any directory components,
642 like this:
643 objcopy --add-gnu-debuglink=foo.debug
645 At debug time the debugger will attempt to look for the separate
647 debug info file in a set of known locations. The exact set of
648 these locations varies depending upon the distribution being used,
649 but it typically includes:
650 "* The same directory as the executable."
652 "* A sub-directory of the directory containing the executable"
653 called .debug
654 "* A global debug directory such as /usr/lib/debug."
656 As long as the debug info file has been installed into one of these
658 locations before the debugger is run everything should work
659 correctly.
660 --keep-file-symbols
662 When stripping a file, perhaps with --strip-debug or
663 --strip-unneeded, retain any symbols specifying source file names,
664 which would otherwise get stripped.
665 --only-keep-debug
667 Strip a file, removing contents of any sections that would not be
668 stripped by --strip-debug and leaving the debugging sections
669 intact. In ELF files, this preserves all note sections in the
670 output.
671 Note - the section headers of the stripped sections are preserved,
673 including their sizes, but the contents of the section are
674 discarded. The section headers are preserved so that other tools
675 can match up the debuginfo file with the real executable, even if
676 that executable has been relocated to a different address space.
677 The intention is that this option will be used in conjunction with
679 --add-gnu-debuglink to create a two part executable. One a
680 stripped binary which will occupy less space in RAM and in a
681 distribution and the second a debugging information file which is
682 only needed if debugging abilities are required. The suggested
683 procedure to create these files is as follows:
684 1.<Link the executable as normal. Assuming that is is called>
686 "foo" then...
687 1.<Run "objcopy --only-keep-debug foo foo.dbg" to>
689 create a file containing the debugging info.
690 1.<Run "objcopy --strip-debug foo" to create a>
692 stripped executable.
693 1.<Run "objcopy --add-gnu-debuglink=foo.dbg foo">
695 to add a link to the debugging info into the stripped
696 executable.
697 Note---the choice of ".dbg" as an extension for the debug info file
699 is arbitrary. Also the "--only-keep-debug" step is optional. You
700 could instead do this:
701 1.<Link the executable as normal.>
703 1.<Copy "foo" to "foo.full">
704 1.<Run "objcopy --strip-debug foo">
705 1.<Run "objcopy --add-gnu-debuglink=foo.full foo">
706 i.e., the file pointed to by the --add-gnu-debuglink can be the
708 full executable. It does not have to be a file created by the
709 --only-keep-debug switch.
710 Note---this switch is only intended for use on fully linked files.
712 It does not make sense to use it on object files where the
713 debugging information may be incomplete. Besides the gnu_debuglink
714 feature currently only supports the presence of one filename
715 containing debugging information, not multiple filenames on a one-
716 per-object-file basis.
717 --strip-dwo
719 Remove the contents of all DWARF .dwo sections, leaving the
720 remaining debugging sections and all symbols intact. This option
721 is intended for use by the compiler as part of the -gsplit-dwarf
722 option, which splits debug information between the .o file and a
723 separate .dwo file. The compiler generates all debug information
724 in the same file, then uses the --extract-dwo option to copy the
725 .dwo sections to the .dwo file, then the --strip-dwo option to
726 remove those sections from the original .o file.
727 --extract-dwo
729 Extract the contents of all DWARF .dwo sections. See the
730 --strip-dwo option for more information.
731 --file-alignment num
733 Specify the file alignment. Sections in the file will always begin
734 at file offsets which are multiples of this number. This defaults
735 to 512. [This option is specific to PE targets.]
736 --heap reserve
738 --heap reserve,commit
739 Specify the number of bytes of memory to reserve (and optionally
740 commit) to be used as heap for this program. [This option is
741 specific to PE targets.]
742 --image-base value
744 Use value as the base address of your program or dll. This is the
745 lowest memory location that will be used when your program or dll
746 is loaded. To reduce the need to relocate and improve performance
747 of your dlls, each should have a unique base address and not
748 overlap any other dlls. The default is 0x400000 for executables,
749 and 0x10000000 for dlls. [This option is specific to PE targets.]
750 --section-alignment num
752 Sets the section alignment. Sections in memory will always begin
753 at addresses which are a multiple of this number. Defaults to
754 0x1000. [This option is specific to PE targets.]
755 --stack reserve
757 --stack reserve,commit
758 Specify the number of bytes of memory to reserve (and optionally
759 commit) to be used as stack for this program. [This option is
760 specific to PE targets.]
761 --subsystem which
763 --subsystem which:major
764 --subsystem which:major.minor
765 Specifies the subsystem under which your program will execute. The
766 legal values for which are "native", "windows", "console", "posix",
767 "efi-app", "efi-bsd", "efi-rtd", "sal-rtd", and "xbox". You may
768 optionally set the subsystem version also. Numeric values are also
769 accepted for which. [This option is specific to PE targets.]
770 --extract-symbol
772 Keep the file's section flags and symbols but remove all section
773 data. Specifically, the option:
774 *<removes the contents of all sections;>
776 *<sets the size of every section to zero; and>
777 *<sets the file's start address to zero.>
778 This option is used to build a .sym file for a VxWorks kernel. It
780 can also be a useful way of reducing the size of a --just-symbols
781 linker input file.
782 --compress-debug-sections
784 Compress DWARF debug sections using zlib with SHF_COMPRESSED from
785 the ELF ABI. Note - if compression would actually make a section
786 larger, then it is not compressed.
787 --compress-debug-sections=none
789 --compress-debug-sections=zlib
790 --compress-debug-sections=zlib-gnu
791 --compress-debug-sections=zlib-gabi
792 For ELF files, these options control how DWARF debug sections are
793 compressed. --compress-debug-sections=none is equivalent to
794 --decompress-debug-sections. --compress-debug-sections=zlib and
795 --compress-debug-sections=zlib-gabi are equivalent to
796 --compress-debug-sections. --compress-debug-sections=zlib-gnu
797 compresses DWARF debug sections using zlib. The debug sections are
798 renamed to begin with .zdebug instead of .debug. Note - if
799 compression would actually make a section larger, then it is not
800 compressed nor renamed.
801 --decompress-debug-sections
803 Decompress DWARF debug sections using zlib. The original section
804 names of the compressed sections are restored.
805 --elf-stt-common=yes
807 --elf-stt-common=no
808 For ELF files, these options control whether common symbols should
809 be converted to the "STT_COMMON" or "STT_OBJECT" type.
810 --elf-stt-common=yes converts common symbol type to "STT_COMMON".
811 --elf-stt-common=no converts common symbol type to "STT_OBJECT".
812 -V
814 --version
815 Show the version number of objcopy.
816 -v
818 --verbose
819 Verbose output: list all object files modified. In the case of
820 archives, objcopy -V lists all members of the archive.
821 --help
823 Show a summary of the options to objcopy.
824 --info
826 Display a list showing all architectures and object formats
827 available.
828 @file
830 Read command-line options from file. The options read are inserted
831 in place of the original @file option. If file does not exist, or
832 cannot be read, then the option will be treated literally, and not
833 removed.
834 Options in file are separated by whitespace. A whitespace
836 character may be included in an option by surrounding the entire
837 option in either single or double quotes. Any character (including
838 a backslash) may be included by prefixing the character to be
839 included with a backslash. The file may itself contain additional
840 @file options; any such options will be processed recursively.
841
843 ld(1), objdump(1), and the Info entries for binutils.
844
846 Copyright (c) 1991-2016 Free Software Foundation, Inc.
847 Permission is granted to copy, distribute and/or modify this document
849 under the terms of the GNU Free Documentation License, Version 1.3 or
850 any later version published by the Free Software Foundation; with no
851 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
852 Texts. A copy of the license is included in the section entitled "GNU
853 Free Documentation License".
854binutils-2.27 2016-08-03 OBJCOPY(1)