1OBJCOPY(1)                   GNU Development Tools                  OBJCOPY(1)
2
3
4

NAME

6       objcopy - copy and translate object files
7

SYNOPSIS

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               [-W symbolname|--weaken-symbol=symbolname]
24               [-w|--wildcard]
25               [-x|--discard-all]
26               [-X|--discard-locals]
27               [-b byte|--byte=byte]
28               [-i [breadth]|--interleave[=breadth]]
29               [--interleave-width=width]
30               [-j sectionpattern|--only-section=sectionpattern]
31               [-R sectionpattern|--remove-section=sectionpattern]
32               [--remove-relocations=sectionpattern]
33               [-p|--preserve-dates]
34               [-D|--enable-deterministic-archives]
35               [-U|--disable-deterministic-archives]
36               [--debugging]
37               [--gap-fill=val]
38               [--pad-to=address]
39               [--set-start=val]
40               [--adjust-start=incr]
41               [--change-addresses=incr]
42               [--change-section-address sectionpattern{=,+,-}val]
43               [--change-section-lma sectionpattern{=,+,-}val]
44               [--change-section-vma sectionpattern{=,+,-}val]
45               [--change-warnings] [--no-change-warnings]
46               [--set-section-flags sectionpattern=flags]
47               [--add-section sectionname=filename]
48               [--dump-section sectionname=filename]
49               [--update-section sectionname=filename]
50               [--rename-section oldname=newname[,flags]]
51               [--long-section-names {enable,disable,keep}]
52               [--change-leading-char] [--remove-leading-char]
53               [--reverse-bytes=num]
54               [--srec-len=ival] [--srec-forceS3]
55               [--redefine-sym old=new]
56               [--redefine-syms=filename]
57               [--weaken]
58               [--keep-symbols=filename]
59               [--strip-symbols=filename]
60               [--strip-unneeded-symbols=filename]
61               [--keep-global-symbols=filename]
62               [--localize-symbols=filename]
63               [--globalize-symbols=filename]
64               [--weaken-symbols=filename]
65               [--add-symbol name=[section:]value[,flags]]
66               [--alt-machine-code=index]
67               [--prefix-symbols=string]
68               [--prefix-sections=string]
69               [--prefix-alloc-sections=string]
70               [--add-gnu-debuglink=path-to-file]
71               [--keep-file-symbols]
72               [--only-keep-debug]
73               [--strip-dwo]
74               [--extract-dwo]
75               [--extract-symbol]
76               [--writable-text]
77               [--readonly-text]
78               [--pure]
79               [--impure]
80               [--file-alignment=num]
81               [--heap=size]
82               [--image-base=address]
83               [--section-alignment=num]
84               [--stack=size]
85               [--subsystem=which:major.minor]
86               [--compress-debug-sections]
87               [--decompress-debug-sections]
88               [--elf-stt-common=val]
89               [--merge-notes]
90               [--no-merge-notes]
91               [-v|--verbose]
92               [-V|--version]
93               [--help] [--info]
94               infile [outfile]
95

DESCRIPTION

97       The GNU objcopy utility copies the contents of an object file to
98       another.  objcopy uses the GNU BFD Library to read and write the object
99       files.  It can write the destination object file in a format different
100       from that of the source object file.  The exact behavior of objcopy is
101       controlled by command-line options.  Note that objcopy should be able
102       to copy a fully linked file between any two formats. However, copying a
103       relocatable object file between any two formats may not work as
104       expected.
105
106       objcopy creates temporary files to do its translations and deletes them
107       afterward.  objcopy uses BFD to do all its translation work; it has
108       access to all the formats described in BFD and thus is able to
109       recognize most formats without being told explicitly.
110
111       objcopy can be used to generate S-records by using an output target of
112       srec (e.g., use -O srec).
113
114       objcopy can be used to generate a raw binary file by using an output
115       target of binary (e.g., use -O binary).  When objcopy generates a raw
116       binary file, it will essentially produce a memory dump of the contents
117       of the input object file.  All symbols and relocation information will
118       be discarded.  The memory dump will start at the load address of the
119       lowest section copied into the output file.
120
121       When generating an S-record or a raw binary file, it may be helpful to
122       use -S to remove sections containing debugging information.  In some
123       cases -R will be useful to remove sections which contain information
124       that is not needed by the binary file.
125
126       Note---objcopy is not able to change the endianness of its input files.
127       If the input format has an endianness (some formats do not), objcopy
128       can only copy the inputs into file formats that have the same
129       endianness or which have no endianness (e.g., srec).  (However, see the
130       --reverse-bytes option.)
131

OPTIONS

133       infile
134       outfile
135           The input and output files, respectively.  If you do not specify
136           outfile, objcopy creates a temporary file and destructively renames
137           the result with the name of infile.
138
139       -I bfdname
140       --input-target=bfdname
141           Consider the source file's object format to be bfdname, rather than
142           attempting to deduce it.
143
144       -O bfdname
145       --output-target=bfdname
146           Write the output file using the object format bfdname.
147
148       -F bfdname
149       --target=bfdname
150           Use bfdname as the object format for both the input and the output
151           file; i.e., simply transfer data from source to destination with no
152           translation.
153
154       -B bfdarch
155       --binary-architecture=bfdarch
156           Useful when transforming a architecture-less input file into an
157           object file.  In this case the output architecture can be set to
158           bfdarch.  This option will be ignored if the input file has a known
159           bfdarch.  You can access this binary data inside a program by
160           referencing the special symbols that are created by the conversion
161           process.  These symbols are called _binary_objfile_start,
162           _binary_objfile_end and _binary_objfile_size.  e.g. you can
163           transform a picture file into an object file and then access it in
164           your code using these symbols.
165
166       -j sectionpattern
167       --only-section=sectionpattern
168           Copy only the indicated sections from the input file to the output
169           file.  This option may be given more than once.  Note that using
170           this option inappropriately may make the output file unusable.
171           Wildcard characters are accepted in sectionpattern.
172
173           If the first character of sectionpattern is the exclamation point
174           (!) then matching sections will not be copied, even if earlier use
175           of --only-section on the same command line would otherwise copy it.
176           For example:
177
178                     --only-section=.text.* --only-section=!.text.foo
179
180           will copy all sectinos maching '.text.*' but not the section
181           '.text.foo'.
182
183       -R sectionpattern
184       --remove-section=sectionpattern
185           Remove any section matching sectionpattern from the output file.
186           This option may be given more than once.  Note that using this
187           option inappropriately may make the output file unusable.  Wildcard
188           characters are accepted in sectionpattern.  Using both the -j and
189           -R options together results in undefined behaviour.
190
191           If the first character of sectionpattern is the exclamation point
192           (!) then matching sections will not be removed even if an earlier
193           use of --remove-section on the same command line would otherwise
194           remove it.  For example:
195
196                     --remove-section=.text.* --remove-section=!.text.foo
197
198           will remove all sections matching the pattern '.text.*', but will
199           not remove the section '.text.foo'.
200
201       --remove-relocations=sectionpattern
202           Remove relocations from the output file for any section matching
203           sectionpattern.  This option may be given more than once.  Note
204           that using this option inappropriately may make the output file
205           unusable.  Wildcard characters are accepted in sectionpattern.  For
206           example:
207
208                     --remove-relocations=.text.*
209
210           will remove the relocations for all sections matching the patter
211           '.text.*'.
212
213           If the first character of sectionpattern is the exclamation point
214           (!) then matching sections will not have their relocation removed
215           even if an earlier use of --remove-relocations on the same command
216           line would otherwise cause the relocations to be removed.  For
217           example:
218
219                     --remove-relocations=.text.* --remove-relocations=!.text.foo
220
221           will remove all relocations for sections matching the pattern
222           '.text.*', but will not remove relocations for the section
223           '.text.foo'.
224
225       -S
226       --strip-all
227           Do not copy relocation and symbol information from the source file.
228
229       -g
230       --strip-debug
231           Do not copy debugging symbols or sections from the source file.
232
233       --strip-unneeded
234           Strip all symbols that are not needed for relocation processing.
235
236       -K symbolname
237       --keep-symbol=symbolname
238           When stripping symbols, keep symbol symbolname even if it would
239           normally be stripped.  This option may be given more than once.
240
241       -N symbolname
242       --strip-symbol=symbolname
243           Do not copy symbol symbolname from the source file.  This option
244           may be given more than once.
245
246       --strip-unneeded-symbol=symbolname
247           Do not copy symbol symbolname from the source file unless it is
248           needed by a relocation.  This option may be given more than once.
249
250       -G symbolname
251       --keep-global-symbol=symbolname
252           Keep only symbol symbolname global.  Make all other symbols local
253           to the file, so that they are not visible externally.  This option
254           may be given more than once.
255
256       --localize-hidden
257           In an ELF object, mark all symbols that have hidden or internal
258           visibility as local.  This option applies on top of symbol-specific
259           localization options such as -L.
260
261       -L symbolname
262       --localize-symbol=symbolname
263           Convert a global or weak symbol called symbolname into a local
264           symbol, so that it is not visible externally.  This option may be
265           given more than once.  Note - unique symbols are not converted.
266
267       -W symbolname
268       --weaken-symbol=symbolname
269           Make symbol symbolname weak. This option may be given more than
270           once.
271
272       --globalize-symbol=symbolname
273           Give symbol symbolname global scoping so that it is visible outside
274           of the file in which it is defined.  This option may be given more
275           than once.
276
277       -w
278       --wildcard
279           Permit regular expressions in symbolnames used in other command
280           line options.  The question mark (?), asterisk (*), backslash (\)
281           and square brackets ([]) operators can be used anywhere in the
282           symbol name.  If the first character of the symbol name is the
283           exclamation point (!) then the sense of the switch is reversed for
284           that symbol.  For example:
285
286                     -w -W !foo -W fo*
287
288           would cause objcopy to weaken all symbols that start with "fo"
289           except for the symbol "foo".
290
291       -x
292       --discard-all
293           Do not copy non-global symbols from the source file.
294
295       -X
296       --discard-locals
297           Do not copy compiler-generated local symbols.  (These usually start
298           with L or ..)
299
300       -b byte
301       --byte=byte
302           If interleaving has been enabled via the --interleave option then
303           start the range of bytes to keep at the byteth byte.  byte can be
304           in the range from 0 to breadth-1, where breadth is the value given
305           by the --interleave option.
306
307       -i [breadth]
308       --interleave[=breadth]
309           Only copy a range out of every breadth bytes.  (Header data is not
310           affected).  Select which byte in the range begins the copy with the
311           --byte option.  Select the width of the range with the
312           --interleave-width option.
313
314           This option is useful for creating files to program ROM.  It is
315           typically used with an "srec" output target.  Note that objcopy
316           will complain if you do not specify the --byte option as well.
317
318           The default interleave breadth is 4, so with --byte set to 0,
319           objcopy would copy the first byte out of every four bytes from the
320           input to the output.
321
322       --interleave-width=width
323           When used with the --interleave option, copy width bytes at a time.
324           The start of the range of bytes to be copied is set by the --byte
325           option, and the extent of the range is set with the --interleave
326           option.
327
328           The default value for this option is 1.  The value of width plus
329           the byte value set by the --byte option must not exceed the
330           interleave breadth set by the --interleave option.
331
332           This option can be used to create images for two 16-bit flashes
333           interleaved in a 32-bit bus by passing -b 0 -i 4
334           --interleave-width=2 and -b 2 -i 4 --interleave-width=2 to two
335           objcopy commands.  If the input was '12345678' then the outputs
336           would be '1256' and '3478' respectively.
337
338       -p
339       --preserve-dates
340           Set the access and modification dates of the output file to be the
341           same as those of the input file.
342
343       -D
344       --enable-deterministic-archives
345           Operate in deterministic mode.  When copying archive members and
346           writing the archive index, use zero for UIDs, GIDs, timestamps, and
347           use consistent file modes for all files.
348
349           If binutils was configured with --enable-deterministic-archives,
350           then this mode is on by default.  It can be disabled with the -U
351           option, below.
352
353       -U
354       --disable-deterministic-archives
355           Do not operate in deterministic mode.  This is the inverse of the
356           -D option, above: when copying archive members and writing the
357           archive index, use their actual UID, GID, timestamp, and file mode
358           values.
359
360           This is the default unless binutils was configured with
361           --enable-deterministic-archives.
362
363       --debugging
364           Convert debugging information, if possible.  This is not the
365           default because only certain debugging formats are supported, and
366           the conversion process can be time consuming.
367
368       --gap-fill val
369           Fill gaps between sections with val.  This operation applies to the
370           load address (LMA) of the sections.  It is done by increasing the
371           size of the section with the lower address, and filling in the
372           extra space created with val.
373
374       --pad-to address
375           Pad the output file up to the load address address.  This is done
376           by increasing the size of the last section.  The extra space is
377           filled in with the value specified by --gap-fill (default zero).
378
379       --set-start val
380           Set the start address of the new file to val.  Not all object file
381           formats support setting the start address.
382
383       --change-start incr
384       --adjust-start incr
385           Change the start address by adding incr.  Not all object file
386           formats support setting the start address.
387
388       --change-addresses incr
389       --adjust-vma incr
390           Change the VMA and LMA addresses of all sections, as well as the
391           start address, by adding incr.  Some object file formats do not
392           permit section addresses to be changed arbitrarily.  Note that this
393           does not relocate the sections; if the program expects sections to
394           be loaded at a certain address, and this option is used to change
395           the sections such that they are loaded at a different address, the
396           program may fail.
397
398       --change-section-address sectionpattern{=,+,-}val
399       --adjust-section-vma sectionpattern{=,+,-}val
400           Set or change both the VMA address and the LMA address of any
401           section matching sectionpattern.  If = is used, the section address
402           is set to val.  Otherwise, val is added to or subtracted from the
403           section address.  See the comments under --change-addresses, above.
404           If sectionpattern does not match any sections in the input file, a
405           warning will be issued, unless --no-change-warnings is used.
406
407       --change-section-lma sectionpattern{=,+,-}val
408           Set or change the LMA address of any sections matching
409           sectionpattern.  The LMA address is the address where the section
410           will be loaded into memory at program load time.  Normally this is
411           the same as the VMA address, which is the address of the section at
412           program run time, but on some systems, especially those where a
413           program is held in ROM, the two can be different.  If = is used,
414           the section address is set to val.  Otherwise, val is added to or
415           subtracted from the section address.  See the comments under
416           --change-addresses, above.  If sectionpattern does not match any
417           sections in the input file, a warning will be issued, unless
418           --no-change-warnings is used.
419
420       --change-section-vma sectionpattern{=,+,-}val
421           Set or change the VMA address of any section matching
422           sectionpattern.  The VMA address is the address where the section
423           will be located once the program has started executing.  Normally
424           this is the same as the LMA address, which is the address where the
425           section will be loaded into memory, but on some systems, especially
426           those where a program is held in ROM, the two can be different.  If
427           = is used, the section address is set to val.  Otherwise, val is
428           added to or subtracted from the section address.  See the comments
429           under --change-addresses, above.  If sectionpattern does not match
430           any sections in the input file, a warning will be issued, unless
431           --no-change-warnings is used.
432
433       --change-warnings
434       --adjust-warnings
435           If --change-section-address or --change-section-lma or
436           --change-section-vma is used, and the section pattern does not
437           match any sections, issue a warning.  This is the default.
438
439       --no-change-warnings
440       --no-adjust-warnings
441           Do not issue a warning if --change-section-address or
442           --adjust-section-lma or --adjust-section-vma is used, even if the
443           section pattern does not match any sections.
444
445       --set-section-flags sectionpattern=flags
446           Set the flags for any sections matching sectionpattern.  The flags
447           argument is a comma separated string of flag names.  The recognized
448           names are alloc, contents, load, noload, readonly, code, data, rom,
449           share, and debug.  You can set the contents flag for a section
450           which does not have contents, but it is not meaningful to clear the
451           contents flag of a section which does have contents--just remove
452           the section instead.  Not all flags are meaningful for all object
453           file formats.
454
455       --add-section sectionname=filename
456           Add a new section named sectionname while copying the file.  The
457           contents of the new section are taken from the file filename.  The
458           size of the section will be the size of the file.  This option only
459           works on file formats which can support sections with arbitrary
460           names.  Note - it may be necessary to use the --set-section-flags
461           option to set the attributes of the newly created section.
462
463       --dump-section sectionname=filename
464           Place the contents of section named sectionname into the file
465           filename, overwriting any contents that may have been there
466           previously.  This option is the inverse of --add-section.  This
467           option is similar to the --only-section option except that it does
468           not create a formatted file, it just dumps the contents as raw
469           binary data, without applying any relocations.  The option can be
470           specified more than once.
471
472       --update-section sectionname=filename
473           Replace the existing contents of a section named sectionname with
474           the contents of file filename.  The size of the section will be
475           adjusted to the size of the file.  The section flags for
476           sectionname will be unchanged.  For ELF format files the section to
477           segment mapping will also remain unchanged, something which is not
478           possible using --remove-section followed by --add-section.  The
479           option can be specified more than once.
480
481           Note - it is possible to use --rename-section and --update-section
482           to both update and rename a section from one command line.  In this
483           case, pass the original section name to --update-section, and the
484           original and new section names to --rename-section.
485
486       --add-symbol name=[section:]value[,flags]
487           Add a new symbol named name while copying the file.  This option
488           may be specified multiple times.  If the section is given, the
489           symbol will be associated with and relative to that section,
490           otherwise it will be an ABS symbol.  Specifying an undefined
491           section will result in a fatal error.  There is no check for the
492           value, it will be taken as specified.  Symbol flags can be
493           specified and not all flags will be meaningful for all object file
494           formats.  By default, the symbol will be global.  The special flag
495           'before=othersym' will insert the new symbol in front of the
496           specified othersym, otherwise the symbol(s) will be added at the
497           end of the symbol table in the order they appear.
498
499       --rename-section oldname=newname[,flags]
500           Rename a section from oldname to newname, optionally changing the
501           section's flags to flags in the process.  This has the advantage
502           over using a linker script to perform the rename in that the output
503           stays as an object file and does not become a linked executable.
504
505           This option is particularly helpful when the input format is
506           binary, since this will always create a section called .data.  If
507           for example, you wanted instead to create a section called .rodata
508           containing binary data you could use the following command line to
509           achieve it:
510
511                     objcopy -I binary -O <output_format> -B <architecture> \
512                      --rename-section .data=.rodata,alloc,load,readonly,data,contents \
513                      <input_binary_file> <output_object_file>
514
515       --long-section-names {enable,disable,keep}
516           Controls the handling of long section names when processing "COFF"
517           and "PE-COFF" object formats.  The default behaviour, keep, is to
518           preserve long section names if any are present in the input file.
519           The enable and disable options forcibly enable or disable the use
520           of long section names in the output object; when disable is in
521           effect, any long section names in the input object will be
522           truncated.  The enable option will only emit long section names if
523           any are present in the inputs; this is mostly the same as keep, but
524           it is left undefined whether the enable option might force the
525           creation of an empty string table in the output file.
526
527       --change-leading-char
528           Some object file formats use special characters at the start of
529           symbols.  The most common such character is underscore, which
530           compilers often add before every symbol.  This option tells objcopy
531           to change the leading character of every symbol when it converts
532           between object file formats.  If the object file formats use the
533           same leading character, this option has no effect.  Otherwise, it
534           will add a character, or remove a character, or change a character,
535           as appropriate.
536
537       --remove-leading-char
538           If the first character of a global symbol is a special symbol
539           leading character used by the object file format, remove the
540           character.  The most common symbol leading character is underscore.
541           This option will remove a leading underscore from all global
542           symbols.  This can be useful if you want to link together objects
543           of different file formats with different conventions for symbol
544           names.  This is different from --change-leading-char because it
545           always changes the symbol name when appropriate, regardless of the
546           object file format of the output file.
547
548       --reverse-bytes=num
549           Reverse the bytes in a section with output contents.  A section
550           length must be evenly divisible by the value given in order for the
551           swap to be able to take place. Reversing takes place before the
552           interleaving is performed.
553
554           This option is used typically in generating ROM images for
555           problematic target systems.  For example, on some target boards,
556           the 32-bit words fetched from 8-bit ROMs are re-assembled in
557           little-endian byte order regardless of the CPU byte order.
558           Depending on the programming model, the endianness of the ROM may
559           need to be modified.
560
561           Consider a simple file with a section containing the following
562           eight bytes:  12345678.
563
564           Using --reverse-bytes=2 for the above example, the bytes in the
565           output file would be ordered 21436587.
566
567           Using --reverse-bytes=4 for the above example, the bytes in the
568           output file would be ordered 43218765.
569
570           By using --reverse-bytes=2 for the above example, followed by
571           --reverse-bytes=4 on the output file, the bytes in the second
572           output file would be ordered 34127856.
573
574       --srec-len=ival
575           Meaningful only for srec output.  Set the maximum length of the
576           Srecords being produced to ival.  This length covers both address,
577           data and crc fields.
578
579       --srec-forceS3
580           Meaningful only for srec output.  Avoid generation of S1/S2
581           records, creating S3-only record format.
582
583       --redefine-sym old=new
584           Change the name of a symbol old, to new.  This can be useful when
585           one is trying link two things together for which you have no
586           source, and there are name collisions.
587
588       --redefine-syms=filename
589           Apply --redefine-sym to each symbol pair "old new" listed in the
590           file filename.  filename is simply a flat file, with one symbol
591           pair per line.  Line comments may be introduced by the hash
592           character.  This option may be given more than once.
593
594       --weaken
595           Change all global symbols in the file to be weak.  This can be
596           useful when building an object which will be linked against other
597           objects using the -R option to the linker.  This option is only
598           effective when using an object file format which supports weak
599           symbols.
600
601       --keep-symbols=filename
602           Apply --keep-symbol option to each symbol listed in the file
603           filename.  filename is simply a flat file, with one symbol name per
604           line.  Line comments may be introduced by the hash character.  This
605           option may be given more than once.
606
607       --strip-symbols=filename
608           Apply --strip-symbol option to each symbol listed in the file
609           filename.  filename is simply a flat file, with one symbol name per
610           line.  Line comments may be introduced by the hash character.  This
611           option may be given more than once.
612
613       --strip-unneeded-symbols=filename
614           Apply --strip-unneeded-symbol option to each symbol listed in the
615           file filename.  filename is simply a flat file, with one symbol
616           name per line.  Line comments may be introduced by the hash
617           character.  This option may be given more than once.
618
619       --keep-global-symbols=filename
620           Apply --keep-global-symbol option to each symbol listed in the file
621           filename.  filename is simply a flat file, with one symbol name per
622           line.  Line comments may be introduced by the hash character.  This
623           option may be given more than once.
624
625       --localize-symbols=filename
626           Apply --localize-symbol option to each symbol listed in the file
627           filename.  filename is simply a flat file, with one symbol name per
628           line.  Line comments may be introduced by the hash character.  This
629           option may be given more than once.
630
631       --globalize-symbols=filename
632           Apply --globalize-symbol option to each symbol listed in the file
633           filename.  filename is simply a flat file, with one symbol name per
634           line.  Line comments may be introduced by the hash character.  This
635           option may be given more than once.
636
637       --weaken-symbols=filename
638           Apply --weaken-symbol option to each symbol listed in the file
639           filename.  filename is simply a flat file, with one symbol name per
640           line.  Line comments may be introduced by the hash character.  This
641           option may be given more than once.
642
643       --alt-machine-code=index
644           If the output architecture has alternate machine codes, use the
645           indexth code instead of the default one.  This is useful in case a
646           machine is assigned an official code and the tool-chain adopts the
647           new code, but other applications still depend on the original code
648           being used.  For ELF based architectures if the index alternative
649           does not exist then the value is treated as an absolute number to
650           be stored in the e_machine field of the ELF header.
651
652       --writable-text
653           Mark the output text as writable.  This option isn't meaningful for
654           all object file formats.
655
656       --readonly-text
657           Make the output text write protected.  This option isn't meaningful
658           for all object file formats.
659
660       --pure
661           Mark the output file as demand paged.  This option isn't meaningful
662           for all object file formats.
663
664       --impure
665           Mark the output file as impure.  This option isn't meaningful for
666           all object file formats.
667
668       --prefix-symbols=string
669           Prefix all symbols in the output file with string.
670
671       --prefix-sections=string
672           Prefix all section names in the output file with string.
673
674       --prefix-alloc-sections=string
675           Prefix all the names of all allocated sections in the output file
676           with string.
677
678       --add-gnu-debuglink=path-to-file
679           Creates a .gnu_debuglink section which contains a reference to
680           path-to-file and adds it to the output file.  Note: the file at
681           path-to-file must exist.  Part of the process of adding the
682           .gnu_debuglink section involves embedding a checksum of the
683           contents of the debug info file into the section.
684
685           If the debug info file is built in one location but it is going to
686           be installed at a later time into a different location then do not
687           use the path to the installed location.  The --add-gnu-debuglink
688           option will fail because the installed file does not exist yet.
689           Instead put the debug info file in the current directory and use
690           the --add-gnu-debuglink option without any directory components,
691           like this:
692
693                    objcopy --add-gnu-debuglink=foo.debug
694
695           At debug time the debugger will attempt to look for the separate
696           debug info file in a set of known locations.  The exact set of
697           these locations varies depending upon the distribution being used,
698           but it typically includes:
699
700           "* The same directory as the executable."
701           "* A sub-directory of the directory containing the executable"
702               called .debug
703
704           "* A global debug directory such as /usr/lib/debug."
705
706           As long as the debug info file has been installed into one of these
707           locations before the debugger is run everything should work
708           correctly.
709
710       --keep-file-symbols
711           When stripping a file, perhaps with --strip-debug or
712           --strip-unneeded, retain any symbols specifying source file names,
713           which would otherwise get stripped.
714
715       --only-keep-debug
716           Strip a file, removing contents of any sections that would not be
717           stripped by --strip-debug and leaving the debugging sections
718           intact.  In ELF files, this preserves all note sections in the
719           output.
720
721           Note - the section headers of the stripped sections are preserved,
722           including their sizes, but the contents of the section are
723           discarded.  The section headers are preserved so that other tools
724           can match up the debuginfo file with the real executable, even if
725           that executable has been relocated to a different address space.
726
727           The intention is that this option will be used in conjunction with
728           --add-gnu-debuglink to create a two part executable.  One a
729           stripped binary which will occupy less space in RAM and in a
730           distribution and the second a debugging information file which is
731           only needed if debugging abilities are required.  The suggested
732           procedure to create these files is as follows:
733
734           1.<Link the executable as normal.  Assuming that it is called>
735               "foo" then...
736
737           1.<Run "objcopy --only-keep-debug foo foo.dbg" to>
738               create a file containing the debugging info.
739
740           1.<Run "objcopy --strip-debug foo" to create a>
741               stripped executable.
742
743           1.<Run "objcopy --add-gnu-debuglink=foo.dbg foo">
744               to add a link to the debugging info into the stripped
745               executable.
746
747           Note---the choice of ".dbg" as an extension for the debug info file
748           is arbitrary.  Also the "--only-keep-debug" step is optional.  You
749           could instead do this:
750
751           1.<Link the executable as normal.>
752           1.<Copy "foo" to  "foo.full">
753           1.<Run "objcopy --strip-debug foo">
754           1.<Run "objcopy --add-gnu-debuglink=foo.full foo">
755
756           i.e., the file pointed to by the --add-gnu-debuglink can be the
757           full executable.  It does not have to be a file created by the
758           --only-keep-debug switch.
759
760           Note---this switch is only intended for use on fully linked files.
761           It does not make sense to use it on object files where the
762           debugging information may be incomplete.  Besides the gnu_debuglink
763           feature currently only supports the presence of one filename
764           containing debugging information, not multiple filenames on a one-
765           per-object-file basis.
766
767       --strip-dwo
768           Remove the contents of all DWARF .dwo sections, leaving the
769           remaining debugging sections and all symbols intact.  This option
770           is intended for use by the compiler as part of the -gsplit-dwarf
771           option, which splits debug information between the .o file and a
772           separate .dwo file.  The compiler generates all debug information
773           in the same file, then uses the --extract-dwo option to copy the
774           .dwo sections to the .dwo file, then the --strip-dwo option to
775           remove those sections from the original .o file.
776
777       --extract-dwo
778           Extract the contents of all DWARF .dwo sections.  See the
779           --strip-dwo option for more information.
780
781       --file-alignment num
782           Specify the file alignment.  Sections in the file will always begin
783           at file offsets which are multiples of this number.  This defaults
784           to 512.  [This option is specific to PE targets.]
785
786       --heap reserve
787       --heap reserve,commit
788           Specify the number of bytes of memory to reserve (and optionally
789           commit) to be used as heap for this program.  [This option is
790           specific to PE targets.]
791
792       --image-base value
793           Use value as the base address of your program or dll.  This is the
794           lowest memory location that will be used when your program or dll
795           is loaded.  To reduce the need to relocate and improve performance
796           of your dlls, each should have a unique base address and not
797           overlap any other dlls.  The default is 0x400000 for executables,
798           and 0x10000000 for dlls.  [This option is specific to PE targets.]
799
800       --section-alignment num
801           Sets the section alignment.  Sections in memory will always begin
802           at addresses which are a multiple of this number.  Defaults to
803           0x1000.  [This option is specific to PE targets.]
804
805       --stack reserve
806       --stack reserve,commit
807           Specify the number of bytes of memory to reserve (and optionally
808           commit) to be used as stack for this program.  [This option is
809           specific to PE targets.]
810
811       --subsystem which
812       --subsystem which:major
813       --subsystem which:major.minor
814           Specifies the subsystem under which your program will execute.  The
815           legal values for which are "native", "windows", "console", "posix",
816           "efi-app", "efi-bsd", "efi-rtd", "sal-rtd", and "xbox".  You may
817           optionally set the subsystem version also.  Numeric values are also
818           accepted for which.  [This option is specific to PE targets.]
819
820       --extract-symbol
821           Keep the file's section flags and symbols but remove all section
822           data.  Specifically, the option:
823
824           *<removes the contents of all sections;>
825           *<sets the size of every section to zero; and>
826           *<sets the file's start address to zero.>
827
828           This option is used to build a .sym file for a VxWorks kernel.  It
829           can also be a useful way of reducing the size of a --just-symbols
830           linker input file.
831
832       --compress-debug-sections
833           Compress DWARF debug sections using zlib with SHF_COMPRESSED from
834           the ELF ABI.  Note - if compression would actually make a section
835           larger, then it is not compressed.
836
837       --compress-debug-sections=none
838       --compress-debug-sections=zlib
839       --compress-debug-sections=zlib-gnu
840       --compress-debug-sections=zlib-gabi
841           For ELF files, these options control how DWARF debug sections are
842           compressed.  --compress-debug-sections=none is equivalent to
843           --decompress-debug-sections.  --compress-debug-sections=zlib and
844           --compress-debug-sections=zlib-gabi are equivalent to
845           --compress-debug-sections.  --compress-debug-sections=zlib-gnu
846           compresses DWARF debug sections using zlib.  The debug sections are
847           renamed to begin with .zdebug instead of .debug.  Note - if
848           compression would actually make a section larger, then it is not
849           compressed nor renamed.
850
851       --decompress-debug-sections
852           Decompress DWARF debug sections using zlib.  The original section
853           names of the compressed sections are restored.
854
855       --elf-stt-common=yes
856       --elf-stt-common=no
857           For ELF files, these options control whether common symbols should
858           be converted to the "STT_COMMON" or "STT_OBJECT" type.
859           --elf-stt-common=yes converts common symbol type to "STT_COMMON".
860           --elf-stt-common=no converts common symbol type to "STT_OBJECT".
861
862       --merge-notes
863       --no-merge-notes
864           For ELF files, attempt (or do not attempt) to reduce the size of
865           any SHT_NOTE type sections by removing duplicate notes.
866
867       -V
868       --version
869           Show the version number of objcopy.
870
871       -v
872       --verbose
873           Verbose output: list all object files modified.  In the case of
874           archives, objcopy -V lists all members of the archive.
875
876       --help
877           Show a summary of the options to objcopy.
878
879       --info
880           Display a list showing all architectures and object formats
881           available.
882
883       @file
884           Read command-line options from file.  The options read are inserted
885           in place of the original @file option.  If file does not exist, or
886           cannot be read, then the option will be treated literally, and not
887           removed.
888
889           Options in file are separated by whitespace.  A whitespace
890           character may be included in an option by surrounding the entire
891           option in either single or double quotes.  Any character (including
892           a backslash) may be included by prefixing the character to be
893           included with a backslash.  The file may itself contain additional
894           @file options; any such options will be processed recursively.
895

SEE ALSO

897       ld(1), objdump(1), and the Info entries for binutils.
898
900       Copyright (c) 1991-2018 Free Software Foundation, Inc.
901
902       Permission is granted to copy, distribute and/or modify this document
903       under the terms of the GNU Free Documentation License, Version 1.3 or
904       any later version published by the Free Software Foundation; with no
905       Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
906       Texts.  A copy of the license is included in the section entitled "GNU
907       Free Documentation License".
908
909
910
911binutils-2.30.90                  2018-07-09                        OBJCOPY(1)
Impressum