OBJCOPY.1(1)

NAME
objcopy - copy and translate object files

SYNOPSIS
objcopy [ -F bfdname | --target=bfdname ]
        [ -I bfdname | --input-target=bfdname ]
        [ -O bfdname | --output-target=bfdname ]
        [ -B bfdarch | --binary-architecture=bfdarch ]
        [ -S | --strip-all ] [ -g | --strip-debug ]
        [ -K symbolname | --keep-symbol=symbolname ]
        [ -N symbolname | --strip-symbol=symbolname ]
        [ -G symbolname | --keep-global-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 ]
        [ -j sectionname | --only-section=sectionname ]
        [ -R sectionname | --remove-section=sectionname ]
        [ -p | --preserve-dates ] [ --debugging ]
        [ --gap-fill=val ] [ --pad-to=address ]
        [ --set-start=val ] [ --adjust-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=ival ] [ --srec-forceS3 ]
        [ --redefine-sym old=new ] [ --weaken ]
        [ --keep-symbols=filename ]
        [ --strip-symbols=filename ]
        [ --keep-global-symbols=filename ]
        [ --localize-symbols=filename ]
        [ --weaken-symbols=filename ]
        [ -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. Note that "objcopy" should be able to copy a fully linked file between any two formats. However, copying a relocatable object file between any two formats may not work as expected.

"objcopy" creates temporary files to do its translations and deletes them afterward. "objcopy" uses BFD to do all its translation work; it has access to all the formats described in BFD 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 load 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 that is not needed by the binary file.

Note - "objcopy" is not able to change the endianness of its input files. If the input format has an endianness, (some formats do not), "objcopy" can only copy the inputs into file formats that have the same endianness or which have no endianness (eg srec).

OPTIONS
The input and output files, respectively. If you do not specify outfile, "objcopy" creates a temporary file and destructively renames the result with the name of infile. Consider the source file's object format to be bfdname, rather than attempting to deduce it. Write the output file using the object format 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. Useful when transforming a raw binary input file into an object file. In this case the output architecture can be set to bfdarch. This option will be ignored if the input file has a known bfdarch. You can access this binary data inside a program by referencing the special symbols that are created by the conversion process. These symbols are called _binary_objfile_start, _binary_objfile_end and _binary_objfile_size. e.g. you can transform a picture file into an object file and then access it in your code using these symbols. Copy only the named section from the input file to the output file. This option may be given more than once. Note that using this option inappropriately may make the output file unusable. Remove any section named sectionname from the output file. This option may be given more than once. Note that using this option inappropriately may make the output file unusable. Do not copy relocation and symbol information from the source file. Do not copy debugging symbols from the source file. Strip all symbols that are not needed for relocation processing. Copy only symbol symbolname from the source file. This option may be given more than once. Do not copy symbol symbolname from the source file. This option may be given more than once. Keep only symbol symbolname global. Make all other symbols local to the file, so that they are not visible externally. This option may be given more than once. Make symbol symbolname local to the file, so that it is not visible externally. This option may be given more than once. Make symbol symbolname weak. This option may be given more than once. Do not copy non-global symbols from the source file. Do not copy compiler-generated local symbols. (These usually start with L or ..) Keep only every byteth byte of the input file (header data is not affected). byte can be in the range from 0 to interleave-1, where interleave is given by the -i or --interleave option, or the default of 4. This option is useful for creating files to program ROM. It is typically used with an "srec" output target. Only copy one out of every interleave bytes. Select which byte to copy with the -b or --byte option. The default is 4. "objcopy" ignores this option if you do not specify either -b or --byte. Set the access and modification dates of the output file to be the same as those of the input file. 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. 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 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 the start address of the new file to val. Not all object file formats support setting the start address. Change the start address by adding incr. Not all object file formats support setting the start address. Change the VMA and LMA addresses 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. Set or change both the VMA address and 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. Set or change the LMA address of the named section. The LMA address is the address where the section will be loaded into memory at program load time. Normally this is the same as the VMA address, which is the address of the section at program run time, but on some systems, especially those where a program is held in ROM, the two can be different. 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. Set or change the VMA address of the named section. The VMA address is the address where the section will be located once the program has started executing. Normally this is the same as the LMA address, which is the address where the section will be loaded into memory, but on some systems, especially those where a program is held in ROM, the two can be different. 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. If --change-section-address or --change-section-lma or --change-section-vma is used, and the named section does not exist, issue a warning. This is the default. Do not issue a warning if --change-section-address or --adjust-section-lma or --adjust-section-vma is used, even if the named section does not exist. 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. You can set the contents flag for a section which does not have contents, but it is not meaningful to clear the contents flag of a section which does have contents--just remove the section instead. Not all flags are meaningful for all object file formats. 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. 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. 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 file. Meaningful only for srec output. Set the maximum length of the Srecords being produced to ival. This length covers both address, data and crc fields. Meaningful only for srec output. Avoid generation of S1/S2 records, creating S3-only record format. Change the name of a 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. Change all global symbols in the file to be weak. This can be useful when building an object which will be linked against other objects using the "-R" option to the linker. This option is only effective when using an object file format which supports weak symbols. Apply --keep-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. Apply --strip-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. Apply --keep-global-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. Apply --localize-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. Apply --weaken-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. Show the version number of "objcopy". Verbose output: list all object files modified. In the case of archives, objcopy -V lists all members of the archive. Show a summary of the options to "objcopy".

SEE ALSO
ld(1), objdump(1), and the Info entries for binutils.

COPYRIGHT
Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".