objcopy.1

MinGW+MSYS必备的开发工具链

\&\fBreadonly\fR, \fBcode\fR, \fBdata\fR, \fBrom\fR, \fBshare\fR, and
\&\fBdebug\fR.  You can set the \fBcontents\fR flag for a section which
does not have contents, but it is not meaningful to clear the
\&\fBcontents\fR flag of a section which does have contents\*(--just remove
the section instead.  Not all flags are meaningful for all object file
formats.
.IP "\fB\-\-add\-section\fR \fIsectionname\fR\fB=\fR\fIfilename\fR" 4
.IX Item "--add-section sectionname=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.
.IP "\fB\-\-rename\-section\fR \fIoldname\fR\fB=\fR\fInewname\fR\fB[,\fR\fIflags\fR\fB]\fR" 4
.IX Item "--rename-section oldname=newname[,flags]"
Rename a section from \fIoldname\fR to \fInewname\fR, optionally
changing the section's flags to \fIflags\fR in the process.  This has
the advantage over usng a linker script to perform the rename in that
the output stays as an object file and does not become a linked
executable.
.Sp
This option is particularly helpful when the input format is binary,
since this will always create a section called .data.  If for example,
you wanted instead to create a section called .rodata containing binary
data you could use the following command line to achieve it:
.Sp
.Vb 3
\&          objcopy -I binary -O <output_format> -B <architecture> \e
\&           --rename-section .data=.rodata,alloc,load,readonly,data,contents \e
\&           <input_binary_file> <output_object_file>
.Ve
.IP "\fB\-\-change\-leading\-char\fR" 4
.IX Item "--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 \fBobjcopy\fR 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.
.IP "\fB\-\-remove\-leading\-char\fR" 4
.IX Item "--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\fR because it always changes the symbol name
when appropriate, regardless of the object file format of the output
file.
.IP "\fB\-\-srec\-len=\fR\fIival\fR" 4
.IX Item "--srec-len=ival"
Meaningful only for srec output.  Set the maximum length of the Srecords
being produced to \fIival\fR.  This length covers both address, data and
crc fields.
.IP "\fB\-\-srec\-forceS3\fR" 4
.IX Item "--srec-forceS3"
Meaningful only for srec output.  Avoid generation of S1/S2 records, 
creating S3\-only record format.
.IP "\fB\-\-redefine\-sym\fR \fIold\fR\fB=\fR\fInew\fR" 4
.IX Item "--redefine-sym old=new"
Change the name of a 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.
.IP "\fB\-\-redefine\-syms=\fR\fIfilename\fR" 4
.IX Item "--redefine-syms=filename"
Apply \fB\-\-redefine\-sym\fR to each symbol pair "\fIold\fR \fInew\fR"
listed in the file \fIfilename\fR.  \fIfilename\fR is simply a flat file,
with one symbol pair per line.  Line comments may be introduced by the hash
character.  This option may be given more than once.
.IP "\fB\-\-weaken\fR" 4
.IX Item "--weaken"
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 \fB\-R\fR option to the linker.  This option is only effective when
using an object file format which supports weak symbols.
.IP "\fB\-\-keep\-symbols=\fR\fIfilename\fR" 4
.IX Item "--keep-symbols=filename"
Apply \fB\-\-keep\-symbol\fR option to each symbol listed in the file
\&\fIfilename\fR.  \fIfilename\fR 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.
.IP "\fB\-\-strip\-symbols=\fR\fIfilename\fR" 4
.IX Item "--strip-symbols=filename"
Apply \fB\-\-strip\-symbol\fR option to each symbol listed in the file
\&\fIfilename\fR.  \fIfilename\fR 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.
.IP "\fB\-\-strip\-unneeded\-symbols=\fR\fIfilename\fR" 4
.IX Item "--strip-unneeded-symbols=filename"
Apply \fB\-\-strip\-unneeded\-symbol\fR option to each symbol listed in
the file \fIfilename\fR.  \fIfilename\fR 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.
.IP "\fB\-\-keep\-global\-symbols=\fR\fIfilename\fR" 4
.IX Item "--keep-global-symbols=filename"
Apply \fB\-\-keep\-global\-symbol\fR option to each symbol listed in the
file \fIfilename\fR.  \fIfilename\fR 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.
.IP "\fB\-\-localize\-symbols=\fR\fIfilename\fR" 4
.IX Item "--localize-symbols=filename"
Apply \fB\-\-localize\-symbol\fR option to each symbol listed in the file
\&\fIfilename\fR.  \fIfilename\fR 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.
.IP "\fB\-\-globalize\-symbols=\fR\fIfilename\fR" 4
.IX Item "--globalize-symbols=filename"
Apply \fB\-\-globalize\-symbol\fR option to each symbol listed in the file
\&\fIfilename\fR.  \fIfilename\fR 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.
.IP "\fB\-\-weaken\-symbols=\fR\fIfilename\fR" 4
.IX Item "--weaken-symbols=filename"
Apply \fB\-\-weaken\-symbol\fR option to each symbol listed in the file
\&\fIfilename\fR.  \fIfilename\fR 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.
.IP "\fB\-\-alt\-machine\-code=\fR\fIindex\fR" 4
.IX Item "--alt-machine-code=index"
If the output architecture has alternate machine codes, use the
\&\fIindex\fRth code instead of the default one.  This is useful in case
a machine is assigned an official code and the tool-chain adopts the 
new code, but other applications still depend on the original code
being used.  For \s-1ELF\s0 based architectures if the \fIindex\fR
alternative does not exist then the value is treated as an absolute
number to be stored in the e_machine field of the \s-1ELF\s0 header.
.IP "\fB\-\-writable\-text\fR" 4
.IX Item "--writable-text"
Mark the output text as writable.  This option isn't meaningful for all
object file formats.
.IP "\fB\-\-readonly\-text\fR" 4
.IX Item "--readonly-text"
Make the output text write protected.  This option isn't meaningful for all
object file formats.
.IP "\fB\-\-pure\fR" 4
.IX Item "--pure"
Mark the output file as demand paged.  This option isn't meaningful for all
object file formats.
.IP "\fB\-\-impure\fR" 4
.IX Item "--impure"
Mark the output file as impure.  This option isn't meaningful for all
object file formats.
.IP "\fB\-\-prefix\-symbols=\fR\fIstring\fR" 4
.IX Item "--prefix-symbols=string"
Prefix all symbols in the output file with \fIstring\fR.
.IP "\fB\-\-prefix\-sections=\fR\fIstring\fR" 4
.IX Item "--prefix-sections=string"
Prefix all section names in the output file with \fIstring\fR.
.IP "\fB\-\-prefix\-alloc\-sections=\fR\fIstring\fR" 4
.IX Item "--prefix-alloc-sections=string"
Prefix all the names of all allocated sections in the output file with
\&\fIstring\fR.
.IP "\fB\-\-add\-gnu\-debuglink=\fR\fIpath-to-file\fR" 4
.IX Item "--add-gnu-debuglink=path-to-file"
Creates a .gnu_debuglink section which contains a reference to \fIpath-to-file\fR
and adds it to the output file.
.IP "\fB\-\-keep\-file\-symbols\fR" 4
.IX Item "--keep-file-symbols"
When stripping a file, perhaps with \fB\-\-strip\-debug\fR or
\&\fB\-\-strip\-unneeded\fR, retain any symbols specifying source file names,
which would otherwise get stripped.
.IP "\fB\-\-only\-keep\-debug\fR" 4
.IX Item "--only-keep-debug"
Strip a file, removing contents of any sections that would not be
stripped by \fB\-\-strip\-debug\fR and leaving the debugging sections
intact.
.Sp
The intention is that this option will be used in conjunction with
\&\fB\-\-add\-gnu\-debuglink\fR to create a two part executable.  One a
stripped binary which will occupy less space in \s-1RAM\s0 and in a
distribution and the second a debugging information file which is only
needed if debugging abilities are required.  The suggested procedure
to create these files is as follows:
.RS 4
.IP "1.<Link the executable as normal.  Assuming that is is called>" 4
.IX Item "1.<Link the executable as normal.  Assuming that is is called>"
\&\f(CW\*(C`foo\*(C'\fR then...
.ie n .IP "1.<Run ""objcopy \-\-only\-keep\-debug foo foo.dbg"" to>" 4
.el .IP "1.<Run \f(CWobjcopy \-\-only\-keep\-debug foo foo.dbg\fR to>" 4
.IX Item "1.<Run objcopy --only-keep-debug foo foo.dbg to>"
create a file containing the debugging info.
.ie n .IP "1.<Run ""objcopy \-\-strip\-debug foo"" to create a>" 4
.el .IP "1.<Run \f(CWobjcopy \-\-strip\-debug foo\fR to create a>" 4
.IX Item "1.<Run objcopy --strip-debug foo to create a>"
stripped executable.
.ie n .IP "1.<Run ""objcopy \-\-add\-gnu\-debuglink=foo.dbg foo"">" 4
.el .IP "1.<Run \f(CWobjcopy \-\-add\-gnu\-debuglink=foo.dbg foo\fR>" 4
.IX Item "1.<Run objcopy --add-gnu-debuglink=foo.dbg foo>"
to add a link to the debugging info into the stripped executable.
.RE
.RS 4
.Sp
Note \- the choice of \f(CW\*(C`.dbg\*(C'\fR as an extension for the debug info
file is arbitrary.  Also the \f(CW\*(C`\-\-only\-keep\-debug\*(C'\fR step is
optional.  You could instead do this:
.IP "1.<Link the executable as normal.>" 4
.IX Item "1.<Link the executable as normal.>"
.PD 0
.ie n .IP "1.<Copy ""foo""\fR to  \f(CW""foo.full"">" 4
.el .IP "1.<Copy \f(CWfoo\fR to  \f(CWfoo.full\fR>" 4
.IX Item "1.<Copy foo to  foo.full>"
.ie n .IP "1.<Run ""objcopy \-\-strip\-debug foo"">" 4
.el .IP "1.<Run \f(CWobjcopy \-\-strip\-debug foo\fR>" 4
.IX Item "1.<Run objcopy --strip-debug foo>"
.ie n .IP "1.<Run ""objcopy \-\-add\-gnu\-debuglink=foo.full foo"">" 4
.el .IP "1.<Run \f(CWobjcopy \-\-add\-gnu\-debuglink=foo.full foo\fR>" 4
.IX Item "1.<Run objcopy --add-gnu-debuglink=foo.full foo>"
.RE
.RS 4
.PD
.Sp
i.e., the file pointed to by the \fB\-\-add\-gnu\-debuglink\fR can be the
full executable.  It does not have to be a file created by the
\&\fB\-\-only\-keep\-debug\fR switch.
.RE
.IP "\fB\-V\fR" 4
.IX Item "-V"
.PD 0
.IP "\fB\-\-version\fR" 4
.IX Item "--version"
.PD
Show the version number of \fBobjcopy\fR.
.IP "\fB\-v\fR" 4
.IX Item "-v"
.PD 0
.IP "\fB\-\-verbose\fR" 4
.IX Item "--verbose"
.PD
Verbose output: list all object files modified.  In the case of
archives, \fBobjcopy \-V\fR lists all members of the archive.
.IP "\fB\-\-help\fR" 4
.IX Item "--help"
Show a summary of the options to \fBobjcopy\fR.
.IP "\fB\-\-info\fR" 4
.IX Item "--info"
Display a list showing all architectures and object formats available.
.IP "\fB@\fR\fIfile\fR" 4
.IX Item "@file"
Read command-line options from \fIfile\fR.  The options read are
inserted in place of the original @\fIfile\fR option.  If \fIfile\fR
does not exist, or cannot be read, then the option will be treated
literally, and not removed.  
.Sp
Options in \fIfile\fR are separated by whitespace.  A whitespace
character may be included in an option by surrounding the entire
option in either single or double quotes.  Any character (including a
backslash) may be included by prefixing the character to be included
with a backslash.  The \fIfile\fR may itself contain additional
@\fIfile\fR options; any such options will be processed recursively.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fIld\fR\|(1), \fIobjdump\fR\|(1), and the Info entries for \fIbinutils\fR.
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
.PP
Permission is granted to copy, distribute and/or modify this document
under the terms of the \s-1GNU\s0 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 \*(L"\s-1GNU\s0 Free Documentation License\*(R".