objcopy(1)

NAME
objcopy - copy and translate object files

SYNOPSIS

objcopy
    [-F bfdname | --target=bfdname] [-I bfdname | --input-target=bfdname] [-O bfdname | --output-target=bfdname] [-j sectionname | --only-section=sectionname] [-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] [--srec-len=val] [--srec-forceS3] [--redefine-sym old=new] [--weaken] [-v | --verbose] [-V | --version] [--help] infile [outfile]

DESCRIPTION
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.

OPTIONS

-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.

-j sectionname, --only-section=sectionname
    Copy only the named section from the input file to the output file, discarding all other sections. This option may be given more than once. Note that using this option inappropriately may make the output file unusable.

-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, contents, load, noload, readonly, code, data, rom, share, and debug. 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

--srec-len=val
    Meaningful only for srec output. Set the length of the Srecords to val. This length covers both the address, data and crc fields.

--srec-forceS3
    Meaningful only for srec output. Avoid generation of S1/S2 records, creating S3-only record format.

--redefine-sym old=new
    Change the name of symbol old to new. This can be useful when one is trying link two things together for which you have no source, and there are name collisions.

--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.

SEE ALSO
`binutils' entry in info; The GNU Binary Utilities, Roland H. Pesch (June 1993).

COPYING
Copyright (c) 1993, 94, 95, 96, 97, 98, 1999, 2000 Free Software Foundation, Inc.

This document is distributed under the terms of the GNU Free Documentation License, version 1.1. That license is described in the sources for this manual page, but it is not displayed here in order to make this manual more consise. Copies of this license can also be obtained from: http://www.gnu.org/copyleft/.