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OBJCOPY(1)                   GNU Development Tools                  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]
               [-B bfdarch|--binary-architecture=bfdarch]
               [-S|--strip-all]
               [-g|--strip-debug]
               [-K symbolname|--keep-symbol=symbolname]
               [-N symbolname|--strip-symbol=symbolname]
               [--strip-unneeded-symbol=symbolname]
               [-G symbolname|--keep-global-symbol=symbolname]
               [--localize-hidden]
               [-L symbolname|--localize-symbol=symbolname]
               [--globalize-symbol=symbolname]
               [-W symbolname|--weaken-symbol=symbolname]
               [-w|--wildcard]
               [-x|--discard-all]
               [-X|--discard-locals]
               [-b byte|--byte=byte]
               [-i interleave|--interleave=interleave]
               [-j sectionname|--only-section=sectionname]
               [-R sectionname|--remove-section=sectionname]
               [-p|--preserve-dates]
               [--debugging]
               [--gap-fill=val]
               [--pad-to=address]
               [--set-start=val]
               [--adjust-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]
               [--rename-section oldname=newname[,flags]]
               [--change-leading-char] [--remove-leading-char]
               [--reverse-bytes=num]
               [--srec-len=ival] [--srec-forceS3]
               [--redefine-sym old=new]
               [--redefine-syms=filename]
               [--weaken]
               [--keep-symbols=filename]
               [--strip-symbols=filename]
               [--strip-unneeded-symbols=filename]
               [--keep-global-symbols=filename]
               [--localize-symbols=filename]
               [--globalize-symbols=filename]
               [--weaken-symbols=filename]
               [--alt-machine-code=index]
               [--prefix-symbols=string]
               [--prefix-sections=string]
               [--prefix-alloc-sections=string]
               [--add-gnu-debuglink=path-to-file]
               [--keep-file-symbols]
               [--only-keep-debug]
               [--extract-symbol]
               [--writable-text]
               [--readonly-text]
               [--pure]
               [--impure]
               [-v|--verbose]
               [-V|--version]
               [--help] [--info]
               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.  Note that objcopy should be able
       to copy a fully linked file between any two formats. However, copying a
       relocatable object file between any two formats may not work as
       expected.

       objcopy creates temporary files to do its translations and deletes them
       afterward.  objcopy uses BFD to do all its translation work; it has
       access to all the formats described in BFD 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 load 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
       that is not needed by the binary file.

       Note---objcopy is not able to change the endianness of its input files.
       If the input format has an endianness (some formats do not), objcopy
       can only copy the inputs into file formats that have the same
       endianness or which have no endianness (e.g., srec).  (However, see the
       --reverse-bytes option.)

OPTIONS
       infile
       outfile
           The input and output files, respectively.  If you do not specify
           outfile, objcopy creates a temporary file and destructively renames
           the result with the name of infile.

       -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.

       -B bfdarch
       --binary-architecture=bfdarch
           Useful when transforming a raw binary input file into an object
           file.  In this case the output architecture can be set to bfdarch.
           This option will be ignored if the input file has a known bfdarch.
           You can access this binary data inside a program by referencing the
           special symbols that are created by the conversion process.  These
           symbols are called _binary_objfile_start, _binary_objfile_end and
           _binary_objfile_size.  e.g. you can transform a picture file into
           an object file and then access it in your code using these symbols.

       -j sectionname
       --only-section=sectionname
           Copy only the named section from the input file to the output file.
           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 any section named sectionname from the output 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 or sections from the source file.

       --strip-unneeded
           Strip all symbols that are not needed for relocation processing.

       -K symbolname
       --keep-symbol=symbolname
           When stripping symbols, keep symbol symbolname even if it would
           normally be stripped.  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.

       --strip-unneeded-symbol=symbolname
           Do not copy symbol symbolname from the source file unless it is
           needed by a relocation.  This option may be given more than once.

       -G symbolname
       --keep-global-symbol=symbolname
           Keep only symbol symbolname global.  Make all other symbols local
           to the file, so that they are not visible externally.  This option
           may be given more than once.

       --localize-hidden
           In an ELF object, mark all symbols that have hidden or internal
           visibility as local.  This option applies on top of symbol-specific
           localization options such as -L.

       -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.

       --globalize-symbol=symbolname
           Give symbol symbolname global scoping so that it is visible outside
           of the file in which it is defined.  This option may be given more
           than once.

       -w
       --wildcard
           Permit regular expressions in symbolnames used in other command
           line options.  The question mark (?), asterisk (*), backslash (\)
           and square brackets ([]) operators can be used anywhere in the
           symbol name.  If the first character of the symbol name is the
           exclamation point (!) then the sense of the switch is reversed for
           that symbol.  For example:

                     -w -W !foo -W fo*

           would cause objcopy to weaken all symbols that start with "fo"
           except for the symbol "foo".

       -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 interleave-1, where
           interleave is given by the -i or --interleave option, or the
           default of 4.  This option is useful for creating files to program
           ROM.  It is typically used with an "srec" output target.

       -i interleave
       --interleave=interleave
           Only copy one out of every interleave bytes.  Select which byte to
           copy with the -b or --byte option.  The default is 4.  objcopy
           ignores this option if you do not specify either -b or --byte.

       -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
           Change the start address by adding incr.  Not all object file
           formats support setting the start address.

       --change-addresses incr
       --adjust-vma incr
           Change the VMA and LMA addresses 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 change both the VMA address and 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-lma section{=,+,-}val
           Set or change the LMA address of the named section.  The LMA
           address is the address where the section will be loaded into memory
           at program load time.  Normally this is the same as the VMA
           address, which is the address of the section at program run time,
           but on some systems, especially those where a program is held in
           ROM, the two can be different.  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.  The VMA
           address is the address where the section will be located once the
           program has started executing.  Normally this is the same as the
           LMA address, which is the address where the section will be loaded
           into memory, but on some systems, especially those where a program
           is held in ROM, the two can be different.  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-address or --change-section-lma or
           --change-section-vma 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-address or
           --adjust-section-lma or --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,
           contents, load, noload, readonly, code, data, rom, share, and
           debug.  You can set the contents flag for a section which does not
           have contents, but it is not meaningful to clear the contents flag
           of a section which does have contents--just remove the section
           instead.  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.

       --rename-section oldname=newname[,flags]
           Rename a section from oldname to newname, optionally changing the
           section's flags to flags 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.

           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:

                     objcopy -I binary -O <output_format> -B <architecture> \
                      --rename-section .data=.rodata,alloc,load,readonly,data,contents \
                      <input_binary_file> <output_object_file>

       --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 file.

       --reverse-bytes=num
           Reverse the bytes in a section with output contents.  A section
           length must be evenly divisible by the value given in order for the
           swap to be able to take place. Reversing takes place before the
           interleaving is performed.

           This option is used typically in generating ROM images for
           problematic target systems.  For example, on some target boards,
           the 32-bit words fetched from 8-bit ROMs are re-assembled in
           little-endian byte order regardless of the CPU byte order.
           Depending on the programming model, the endianness of the ROM may
           need to be modified.

           Consider a simple file with a section containing the following
           eight bytes:  12345678.

           Using --reverse-bytes=2 for the above example, the bytes in the
           output file would be ordered 21436587.

           Using --reverse-bytes=4 for the above example, the bytes in the
           output file would be ordered 43218765.

           By using --reverse-bytes=2 for the above example, followed by
           --reverse-bytes=4 on the output file, the bytes in the second
           output file would be ordered 34127856.

       --srec-len=ival
           Meaningful only for srec output.  Set the maximum length of the
           Srecords being produced to ival.  This length covers both address,
           data and crc fields.

       --srec-forceS3
           Meaningful only for srec output.  Avoid generation of S1/S2
           records, creating S3-only record format.

       --redefine-sym old=new
           Change the name of a 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.

       --redefine-syms=filename
           Apply --redefine-sym to each symbol pair "old new" listed in the
           file filename.  filename 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.

       --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 -R option to the linker.  This option is only
           effective when using an object file format which supports weak
           symbols.

       --keep-symbols=filename
           Apply --keep-symbol option to each symbol listed in the file
           filename.  filename 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.

       --strip-symbols=filename
           Apply --strip-symbol option to each symbol listed in the file
           filename.  filename 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.

       --strip-unneeded-symbols=filename
           Apply --strip-unneeded-symbol option to each symbol listed in the
           file filename.  filename 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.

       --keep-global-symbols=filename
           Apply --keep-global-symbol option to each symbol listed in the file
           filename.  filename 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.

       --localize-symbols=filename
           Apply --localize-symbol option to each symbol listed in the file
           filename.  filename 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.

       --globalize-symbols=filename
           Apply --globalize-symbol option to each symbol listed in the file
           filename.  filename 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.

       --weaken-symbols=filename
           Apply --weaken-symbol option to each symbol listed in the file
           filename.  filename 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.

       --alt-machine-code=index
           If the output architecture has alternate machine codes, use the
           indexth 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 ELF based architectures if the index alternative
           does not exist then the value is treated as an absolute number to
           be stored in the e_machine field of the ELF header.

       --writable-text
           Mark the output text as writable.  This option isn't meaningful for
           all object file formats.

       --readonly-text
           Make the output text write protected.  This option isn't meaningful
           for all object file formats.

       --pure
           Mark the output file as demand paged.  This option isn't meaningful
           for all object file formats.

       --impure
           Mark the output file as impure.  This option isn't meaningful for
           all object file formats.

       --prefix-symbols=string
           Prefix all symbols in the output file with string.

       --prefix-sections=string
           Prefix all section names in the output file with string.

       --prefix-alloc-sections=string
           Prefix all the names of all allocated sections in the output file
           with string.

       --add-gnu-debuglink=path-to-file
           Creates a .gnu_debuglink section which contains a reference to
           path-to-file and adds it to the output file.

       --keep-file-symbols
           When stripping a file, perhaps with --strip-debug or
           --strip-unneeded, retain any symbols specifying source file names,
           which would otherwise get stripped.

       --only-keep-debug
           Strip a file, removing contents of any sections that would not be
           stripped by --strip-debug and leaving the debugging sections
           intact.  In ELF files, this preserves all note sections in the
           output.

           The intention is that this option will be used in conjunction with
           --add-gnu-debuglink to create a two part executable.  One a
           stripped binary which will occupy less space in RAM 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:

           1.<Link the executable as normal.  Assuming that it is called>
               "foo" then...

           1.<Run "objcopy --only-keep-debug foo foo.dbg" to>
               create a file containing the debugging info.

           1.<Run "objcopy --strip-debug foo" to create a>
               stripped executable.

           1.<Run "objcopy --add-gnu-debuglink=foo.dbg foo">
               to add a link to the debugging info into the stripped
               executable.

           Note - the choice of ".dbg" as an extension for the debug info file
           is arbitrary.  Also the "--only-keep-debug" step is optional.  You
           could instead do this:

           1.<Link the executable as normal.>
           1.<Copy "foo" to  "foo.full">
           1.<Run "objcopy --strip-debug foo">
           1.<Run "objcopy --add-gnu-debuglink=foo.full foo">

           i.e., the file pointed to by the --add-gnu-debuglink can be the
           full executable.  It does not have to be a file created by the
           --only-keep-debug switch.

           Note - this switch is only intended for use on fully linked files.
           It does not make sense to use it on object files where the
           debugging information may be incomplete.  Besides the gnu_debuglink
           feature currently only supports the presence of one filename
           containing debugging information, not multiple filenames on a one-
           per-object-file basis.

       --extract-symbol
           Keep the file's section flags and symbols but remove all section
           data.  Specifically, the option:

           *<sets the virtual and load addresses of every section to zero;>
           *<removes the contents of all sections;>
           *<sets the size of every section to zero; and>
           *<sets the file's start address to zero.>

           This option is used to build a .sym file for a VxWorks kernel.  It
           can also be a useful way of reducing the size of a --just-symbols
           linker input file.

       -V
       --version
           Show the version number of objcopy.

       -v
       --verbose
           Verbose output: list all object files modified.  In the case of
           archives, objcopy -V lists all members of the archive.

       --help
           Show a summary of the options to objcopy.

       --info
           Display a list showing all architectures and object formats
           available.

       @file
           Read command-line options from file.  The options read are inserted
           in place of the original @file option.  If file does not exist, or
           cannot be read, then the option will be treated literally, and not
           removed.

           Options in file 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 file may itself contain additional
           @file options; any such options will be processed recursively.

SEE ALSO
       ld(1), objdump(1), and the Info entries for binutils.

COPYRIGHT
       Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
       2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software
       Foundation, Inc.

       Permission is granted to copy, distribute and/or modify this document
       under the terms of the GNU 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 "GNU
       Free Documentation License".

binutils-2.17.50                  2010-10-30                        OBJCOPY(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SEE ALSO | COPYRIGHT

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