objcopy - copy and translate object files

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] [--redefine-sym old=new] [--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.

-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

--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.

`binutils' entry in infoc ; The GNU Binary Utilitiesc , Roland H. Pesch (June 1993).

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

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