objcopy(1) GNU Development Tools objcopy(1)NAMEobjcopy - copy and translate object files
SYNOPSISobjcopy
[-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]
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
--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 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.
Cygnus Solutions 05 April 2000 objcopy(1)
