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]
[-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] [--adjust-start=incr]
[--adjust-vma=incr]
[--adjust-section-vma=section{=,+,-}val]
[--adjust-warnings] [--no-adjust-warnings]
[--set-section-flags=section=flags]
[--add-section=sectionname=filename]
[--change-leading-char] [--remove-leading-char]
[--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.
-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.
--adjust-start=incr
Adjust the start address by adding incr. Not all
object file formats support setting the start
address.
--adjust-vma=incr
Adjust 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.
--adjust-section-vma=section{=,+,-}val
Set or adjust the 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
--adjust-vma, above. If section does not exist in
the input file, a warning will be issued, unless
--no-adjust-warnings is used.
--adjust-warnings
If --adjust-section-vma is used, and the named
section does not exist, issue a warning. This is
the default.
--no-adjust-warnings
Do not issue a warning if --adjust-section-vma 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 @code{--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.
SEE ALSO
`binutils' entry in info; The GNU Binary Utilities, Roland
H. Pesch(June 1993).
COPYING
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.