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objcopy - copy and translate object files
- objcopy
- [-F bfdname | --target=bfdname]
[-I bfdname | --input-target=bfdname] [-O bfdname | --output-target=bfdname] [-R sectionname | --remove-section=sectionname]
[-S | --strip-all] [-g | --strip-debug] [--strip-unneeded] [-K symbolname | --keep-symbol=symbolname]
[-N symbolname | --strip-symbol=symbolname] [-L symbolname | --localize-symbol=symbolname]
[-W symbolname | --weaken-symbol=symbolname] [-x | --discard-all] [-X | --discard-locals] [-b byte | --byte=byte]
[-i interleave | --interleave=interleave] [-p | --preserve-dates] [--debugging] [--gap-fill=val]
[--pad-to=address] [--set-start=val] [--change-start=incr] [--change-addresses=incr]
[--change-section-address=section{=,+,-}val] [--change-section-lma=section{=,+,-}val]
[--change-section-vma=section{=,+,-}val] [--change-warnings] [--no-change-warnings]
[--set-section-flags=section=flags] [--add-section=sectionname=filename] [--change-leading-char]
[--remove-leading-char] [--weaken] [-v | --verbose] [-V | --version] [--help] infile [outfile]
The GNU objcopy utility copies the contents of an object file
to another. objcopy uses the GNU BFD Library to read and write the object
files. It can write the destination object file in a format different from
that of the source object file. The exact behavior of objcopy is controlled
by command-line options.
objcopy creates temporary files to do its translations
and deletes them afterward. objcopy uses BFD to do all its translation work;
it knows about all the formats BFD knows about, and thus is able to recognize
most formats without being told explicitly.
objcopy can be used to generate
S-records by using an output target of srec (e.g., use -O srec).
objcopy can
be used to generate a raw binary file by using an output target of binary
(e.g., use -O binary). When objcopy generates a raw binary file, it will essentially
produce a memory dump of the contents of the input object file. All symbols
and relocation information will be discarded. The memory dump will start
at the virtual address of the lowest section copied into the output file.
When generating an S-record or a raw binary file, it may be helpful to use
-S to remove sections containing debugging information. In some cases -R
will be useful to remove sections which contain information which is not
needed by the binary file.
infile and outfile are the source and output
files respectively. If you do not specify outfile, objcopy creates a temporary
file and destructively renames the result with the name of the input file.
- -I bfdname, --input-target=bfdname
- Consider the source file's object
format to be bfdname, rather than attempting to deduce it.
- -O bfdname, --output-target=bfdname
- Write the output file using the object format bfdname.
- -F bfdname, --target=bfdname
- Use bfdname as the object format for both the input and the output file;
i.e. simply transfer data from source to destination with no translation.
- -R sectionname, --remove-section=sectionname
- Remove the named section from
the file. This option may be given more than once. Note that using this
option inappropriately may make the output file unusable.
- -S, --strip-all
- Do
not copy relocation and symbol information from the source file.
- -g, --strip-debug
- Do not copy debugging symbols from the source file.
- --strip-unneeded
- Strip
all symbols that are not needed for relocation processing.
- -K symbolname,
--keep-symbol=symbolname
- Copy only symbol symbolname from the source file.
This option may be given more than once.
- -N symbolname, --strip-symbol=symbolname
- Do not copy symbol symbolname from the source file. This option may be given
more than once.
- -L symbolname, --localize-symbol=symbolname
- Make symbol symbolname
local to the file, so that it is not visible externally. This option may
be given more than once.
- -W symbolname, --weaken-symbol=symbolname
- Make symbol
symbolname weak. This option may be given more than once.
- -x, --discard-all
- Do not copy non-global symbols from the source file.
- -X, --discard-locals
- Do
not copy compiler-generated local symbols. (These usually start with "L"
or ".").
- -b byte, --byte=byte
- Keep only every byteth byte of the input file
(header data is not affected). byte can be in the range from 0 to the interleave-1.
This option is useful for creating files to program ROMs. It is typically
used with an srec output target.
- -i interleave, --interleave=interleave
- Only
copy one out of every interleave bytes. Which one to copy is selected by
the -b or --byte option. The default is 4. The interleave is ignored if neither
-b nor --byte is given.
- -p, --preserve-dates
- Set the access and modification dates
of the output file to be the same as those of the input file.
- --debugging
- Convert debugging information, if possible. This is not the default because
only certain debugging formats are supported, and the conversion process
can be time consuming.
- --gap-fill=val
- Fill gaps between sections with val.
This operation applies to the load address (LMA) of the sections. It is
done by increasing the size of the section with the lower address, and
filling in the extra space created with val.
- --pad-to=address
- Pad the output
file up to the load address address. This is done by increasing the size
of the last section. The extra space is filled in with the value specified
by --gap-fill (default zero).
- --set-start=val
- Set the start address of the new
file to val. Not all object file formats support setting the start address.
- --change-start=incr, --adjust-start=incr
- Changes the start address by adding
incr. Not all object file formats support setting the start address.
- --change-addresses=incr,
--adjust-vma=incr
- Changes the address of all sections, as well as the start
address, by adding incr. Some object file formats do not permit section
addresses to be changed arbitrarily. Note that this does not relocate the
sections; if the program expects sections to be loaded at a certain address,
and this option is used to change the sections such that they are loaded
at a different address, the program may fail.
- --change-section-address=section{=,+,-}val,
--adjust-section-vma=section{=,+,-}val
- Set or changes the VMA and LMA addresses
of the named section. If = is used, the section address is set to val. Otherwise,
val is added to or subtracted from the section address. See the comments
under --change-addresses, above. If section does not exist in the input file,
a warning will be issued, unless --no-change-warnings is used.
- --change-section-lma=section{=,+,-}val
- Set or change the LMA address of the named section. If = is used, the section
address is set to val. Otherwise, val is added to or subtracted from the
section address. See the comments under --change-addresses, above. If section
does not exist in the input file, a warning will be issued, unless --no-change-warnings
is used.
- --change-section-vma=section{=,+,-}val
- Set or change the VMA address
of the named section. If = is used, the section address is set to val.
Otherwise, val is added to or subtracted from the section address. See
the comments under --change-addresses, above. If section does not exist in
the input file, a warning will be issued, unless --no-change-warnings is used.
- --change-warnings, --adjust-warnings
- If --change-section-XXX is used, and the named
section does not exist, issue a warning. This is the default.
- --no-change-warnings,
--no-adjust-warnings
- Do not issue a warning if --change-section-XXX is used, even
if the named section does not exist.
- --set-section-flags=section=flags
- Set the
flags for the named section. The flags argument is a comma separated string
of flag names. The recognized names are alloc, load, readonly, code, data,
and rom. Not all flags are meaningful for all object file formats.
- --add-section=sectionname=filename
- Add a new section named sectionname while copying the file. The contents
of the new section are taken from the file filename. The size of the section
will be the size of the file. This option only works on file formats which
can support sections with arbitrary names.
- --change-leading-char
- Some object
file formats use special characters at the start of symbols. The most common
such character is underscore, which compilers often add before every symbol.
This option tells objcopy to change the leading character of every symbol
when it converts between object file formats. If the object file formats
use the same leading character, this option has no effect. Otherwise, it
will add a character, or remove a character, or change a character, as
appropriate.
- --remove-leading-char
- If the first character of a global symbol
is a special symbol leading character used by the object file format, remove
the character. The most common symbol leading character is underscore.
This option will remove a leading underscore from all global symbols. This
can be useful if you want to link together objects of different file formats
with different conventions for symbol names. This is different from --change-leading-char
because it always changes the symbol name when appropriate, regardless
of the object file format of the output
- --weaken
- Change all global symbols
in the file to be weak.
- -v, --verbose
- Verbose output: list all object files
modified. In the case of archives, "objcopy -V" lists all members of the
archive.
- -V, --version
- Show the version number of objcopy and exit.
- --help
- Show
a summary of the options to objcopy and exit.
`binutils' entry in
info; The GNU Binary Utilities, Roland H. Pesch (June 1993).
Copyright
(c) 1993, 94, 95, 96, 1997 Free Software Foundation, Inc.
Permission is
granted to make and distribute verbatim copies of this manual provided
the copyright notice and this permission notice are preserved on all copies.
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission notice
identical to this one.
Permission is granted to copy and distribute translations
of this manual into another language, under the above conditions for modified
versions, except that this permission notice may be included in translations
approved by the Free Software Foundation instead of in the original English.
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