Add --redefine-sym to objcopy.

[deliverable/binutils-gdb.git] / binutils / objcopy.1

.\" Copyright (c) 1991, 93, 94, 95, 96, 97, 98, 1999 Free Software Foundation
.\" See section COPYING for conditions for redistribution
.TH objcopy 1 "1999" "Cygnus Solutions" "GNU Development Tools"
.de BP
.sp
.ti \-.2i
\(**
..

.SH NAME
objcopy \- copy and translate object files

.SH SYNOPSIS
.hy 0
.na
.TP
.B objcopy
.RB "[\|" \-F\ \fIbfdname\fR\ |\ \fB\-\-target=\fIbfdname\fR "\|]" 
.RB "[\|" \-I\ \fIbfdname\fR\ |\ \fB\-\-input\-target=\fIbfdname\fR "\|]" 
.RB "[\|" \-O\ \fIbfdname\fR\ |\ \fB\-\-output\-target=\fIbfdname\fR "\|]" 
.RB "[\|" \-j\ \fIsectionname\fR\ |\ \fB\-\-only\-section=\fIsectionname\fR "\|]"
.RB "[\|" \-R\ \fIsectionname\fR\ |\ \fB\-\-remove\-section=\fIsectionname\fR "\|]"
.RB "[\|" \-S\fR\ |\ \fB\-\-strip\-all\fR "\|]" 
.RB "[\|" \-g\fR\ |\ \fB\-\-strip\-debug\fR "\|]" 
.RB "[\|" \-\-strip\-unneeded\fR "\|]" 
.RB "[\|" \-K\ \fIsymbolname\fR\ |\ \fB\-\-keep\-symbol=\fIsymbolname\fR "\|]" 
.RB "[\|" \-N\ \fIsymbolname\fR\ |\ \fB\-\-strip\-symbol=\fIsymbolname\fR "\|]" 
.RB "[\|" \-L\ \fIsymbolname\fR\ |\ \fB\-\-localize\-symbol=\fIsymbolname\fR "\|]" 
.RB "[\|" \-W\ \fIsymbolname\fR\ |\ \fB\-\-weaken\-symbol=\fIsymbolname\fR "\|]" 
.RB "[\|" \-x\fR\ |\ \fB\-\-discard\-all\fR "\|]" 
.RB "[\|" \-X\fR\ |\ \fB\-\-discard\-locals\fR "\|]" 
.RB "[\|" \-b\ \fIbyte\fR\ |\ \fB\-\-byte=\fIbyte\fR "\|]" 
.RB "[\|" \-i\ \fIinterleave\fR\ |\ \fB\-\-interleave=\fIinterleave\fR "\|]" 
.RB "[\|" \-p\fR\ |\ \fB\-\-preserve\-dates\fR "\|]" 
.RB "[\|" \-\-debugging "\|]"
.RB "[\|" \-\-gap\-fill=\fIval\fR "\|]"
.RB "[\|" \-\-pad\-to=\fIaddress\fR "\|]"
.RB "[\|" \-\-set\-start=\fIval\fR "\|]"
.RB "[\|" \-\-change\-start=\fIincr\fR "\|]"
.RB "[\|" \-\-change\-addresses=\fIincr\fR "\|]"
.RB "[\|" \-\-change\-section\-address\ \fIsection{=,+,-}val\fR "\|]"
.RB "[\|" \-\-change\-section\-lma\ \fIsection{=,+,-}val\fR "\|]"
.RB "[\|" \-\-change\-section\-vma\ \fIsection{=,+,-}val\fR "\|]"
.RB "[\|" \-\-change\-warnings\fR "\|]"
.RB "[\|" \-\-no\-change\-warnings\fR "\|]"
.RB "[\|" \-\-set\-section\-flags\ \fIsection=flags\fR "\|]"
.RB "[\|" \-\-add\-section\ \fIsectionname=filename\fR "\|]"
.RB "[\|" \-\-change\-leading\-char\fR "\|]"
.RB "[\|" \-\-remove\-leading\-char\fR "\|]"
.RB "[\|" \-\-redefine\-sym\ \fIold=new\fR "\|]"
.RB "[\|" \-\-weaken\fR "\|]"
.RB "[\|" \-v\ |\ \-\-verbose\fR "\|]" 
.RB "[\|" \-V\ |\ \-\-version\fR "\|]" 
.RB "[\|" \-\-help\fR "\|]" 
.B infile
.RB "[\|" outfile\fR "\|]" 
.SH DESCRIPTION
The GNU 
.B objcopy
utility copies the contents of an object file to another.  
.B 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 
.B objcopy
is controlled by command-line options.
.PP
.B objcopy
creates temporary files to do its translations and deletes them
afterward.
.B 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.
.PP
.B objcopy
can be used to generate S-records by using an output target of
.B srec
(e.g., use
.B -O srec).
.PP
.B objcopy
can be used to generate a raw binary file by using an output target of
.B binary
(e.g., use
.B -O binary).
When
.B 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.
.PP
When generating an S-record or a raw binary file, it may be helpful to
use
.B -S
to remove sections containing debugging information.  In some cases
.B -R
will be useful to remove sections which contain information which is
not needed by the binary file.
.PP
.I infile
and
.I outfile
are the source and output files respectively.  If you do not specify
.IR outfile ,
.B objcopy
creates a temporary file and destructively renames the result with the
name of the input file.

.SH OPTIONS
.TP
.B \-I \fIbfdname\fR, \fB\-\-input\-target=\fIbfdname
Consider the source file's object format to be 
.IR bfdname ,
rather than attempting to deduce it.
.TP
.B \-O \fIbfdname\fR, \fB\-\-output\-target=\fIbfdname
Write the output file using the object format 
.IR bfdname .
.TP
.B \-F \fIbfdname\fR, \fB\-\-target=\fIbfdname
Use 
.I 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.
.TP
.B \-j \fIsectionname\fR, \fB\-\-only\-section=\fIsectionname
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.
.TP
.B \-R \fIsectionname\fR, \fB\-\-remove-section=\fIsectionname
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.
.TP
.B \-S\fR, \fB\-\-strip\-all
Do not copy relocation and symbol information from the source file.
.TP
.B \-g\fR, \fB\-\-strip\-debug
Do not copy debugging symbols from the source file.
.TP
.B \-\-strip\-unneeded
Strip all symbols that are not needed for relocation processing.
.TP
.B \-K \fIsymbolname\fR, \fB\-\-keep\-symbol=\fIsymbolname
Copy only symbol \fIsymbolname\fP from the source file. This option
may be given more than once.
.TP
.B \-N \fIsymbolname\fR, \fB\-\-strip\-symbol=\fIsymbolname
Do not copy symbol \fIsymbolname\fP from the source file. This option
may be given more than once.
.TP
.B \-L \fIsymbolname\fR, \fB\-\-localize\-symbol=\fIsymbolname
Make symbol \fIsymbolname\fP local to the file, so that it is not
visible externally.  This option may be given more than once.
.TP
.B \-W \fIsymbolname\fR, \fB\-\-weaken\-symbol=\fIsymbolname
Make symbol \fIsymbolname\fP weak. This option may be given more than once.
.TP
.B \-x\fR, \fB\-\-discard\-all
Do not copy non-global symbols from the source file.
.TP
.B \-X\fR, \fB\-\-discard\-locals
Do not copy compiler-generated local symbols. (These usually start
with "L" or ".").
.TP
.B \-b \fIbyte\fR, \fB\-\-byte=\fIbyte
Keep only every \fIbyte\fPth byte of the input file (header data is
not affected).  \fIbyte\fP 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.
.TP
.B \-i \fIinterleave\fR, \fB\-\-interleave=\fIinterleave
Only copy one out of every \fIinterleave\fP bytes.  Which one to copy is
selected by the \fB\-b\fP or \fB\-\-byte\fP option.  The default is 4.
The interleave is ignored if neither \fB\-b\fP nor \fB\-\-byte\fP is given.
.TP
.B \-p\fR, \fB\-\-preserve\-dates
Set the access and modification dates of the output file to be the same
as those of the input file.
.TP
.B \-\-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.
.TP
.B \-\-gap\-fill=\fIval
Fill gaps between sections with \fIval\fP.  This operation applies to
the \fIload address\fP (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 \fIval\fP.
.TP
.B \-\-pad\-to=\fIaddress
Pad the output file up to the load address \fIaddress\fP.  This is
done by increasing the size of the last section.  The extra space is
filled in with the value specified by \fB\-\-gap\-fill\fP (default
zero).
.TP
.B \fB\-\-set\-start=\fIval
Set the start address of the new file to \fIval\fP.  Not all object
file formats support setting the start address.
.TP
.B \fB\-\-change\-start=\fIincr\fR, \fB\-\-adjust\-start=\fIincr
Changes the start address by adding \fIincr\fP.  Not all object file
formats support setting the start address.
.TP
.B \fB\-\-change\-addresses=\fIincr\fR, \fB\-\-adjust\-vma=\fIincr
Changes the address of all sections, as well as the start address, by
adding \fIincr\fP.  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.
.TP
.B \fB\-\-change\-section\-address\ \fIsection{=,+,-}val\fR, \fB\-\-adjust\-section\-vma\ \fIsection{=,+,-}val
Set or changes the VMA and LMA addresses of the named \fIsection\fP.
If \fI=\fP is used, the section address is set to \fIval\fP.
Otherwise, \fIval\fP is added to or subtracted from the section
address.  See the comments under \fB\-\-change\-addresses\fP, above.  If
\fIsection\fP does not exist in the input file, a warning will be
issued, unless \fB\-\-no\-change\-warnings\fP is used.
.TP
.B \fB\-\-change\-section\-lma\ \fIsection{=,+,-}val
Set or change the LMA address of the named \fIsection\fP.  If \fI=\fP is
used, the section address is set to \fIval\fP.  Otherwise, \fIval\fP
is added to or subtracted from the section address.  See the comments
under \fB\-\-change\-addresses\fP, above.  If \fIsection\fP does not exist
in the input file, a warning will be issued, unless
\fB\-\-no\-change\-warnings\fP is used.
.TP
.B \fB\-\-change\-section\-vma\ \fIsection{=,+,-}val
Set or change the VMA address of the named \fIsection\fP.  If \fI=\fP is
used, the section address is set to \fIval\fP.  Otherwise, \fIval\fP
is added to or subtracted from the section address.  See the comments
under \fB\-\-change\-addresses\fP, above.  If \fIsection\fP does not exist
in the input file, a warning will be issued, unless
\fB\-\-no\-change\-warnings\fP is used.
.TP
.B \fB\-\-change\-warnings\fR, \fB\-\-adjust\-warnings
If \fB\-\-change\-section\-XXX\fP is used, and the named section does
not exist, issue a warning.  This is the default.
.TP
.B \fB\-\-no\-change\-warnings\fR, \fB\-\-no\-adjust\-warnings
Do not issue a warning if \fB\-\-change\-section\-XXX\fP is used, even
if the named section does not exist.
.TP
.B \fB\-\-set\-section\-flags\ \fIsection=flags
Set the flags for the named section.  The \fIflags\fP argument is a
comma separated string of flag names.  The recognized names are
\fIalloc\fP, \fIcontents\fP, \fIload\fP, \fInoload\fP, \fIreadonly\fP,
\fIcode\fP, \fIdata\fP, \fIrom\fP, \fIshare\fP, and \fIdebug\fP.  Not
all flags are meaningful for all object file formats.
.TP
.B \fB\-\-add\-section\ \fIsectionname=filename
Add a new section named \fIsectionname\fR while copying the file.  The
contents of the new section are taken from the file \fIfilename\fR.
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.
.TP
.B \-\-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 
.B 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.
.TP
.B \-\-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
\fB\-\-change\-leading\-char\fP because it always changes the symbol name
when appropriate, regardless of the object file format of the output
.TP
.B \-\-redefine\-sym\ \fIold=new
Change the name of symbol \fIold\fR to \fInew\fR.  This can be useful
when one is trying link two things together for which you have no
source, and there are name collisions.
.TP
.B \-\-weaken
Change all global symbols in the file to be weak.
.TP
.B \-v\fR, \fB\-\-verbose
Verbose output: list all object files modified.  In the case of
archives, "\fBobjcopy \-V\fR" lists all members of the archive.
.TP
.B \-V\fR, \fB\-\-version
Show the version number of
.B objcopy
and exit.
.TP
.B \-\-help
Show a summary of the options to
.B objcopy
and exit.
.SH "SEE ALSO"
.RB "`\|" binutils "\|'" 
entry in 
.B
info\c
\&; 
.I
The GNU Binary Utilities\c
\&, Roland H. Pesch (June 1993).

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