sh-rtems-objcopy






objcopy − copy and translate object files

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]
        [−G symbolname−−keep−global−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]
        [−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]
        [−−srec−len=ival ] [−−srec−forceS3]
        [−−redefine−sym old=new ]
        [−−weaken]
        [−−keep−symbols=filename]
        [−−strip−symbols=filename]
        [−−keep−global−symbols=filename]
        [−−localize−symbols=filename]
        [−−weaken−symbols=filename]
        [−−alt−machine−code=index]
        [−v−−verbose]
        [−V−−version]
        [−−help]
        infile [outfile]

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.










                             ‐2‐


     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 (eg srec).



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









                             ‐3‐


    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 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.










                             ‐4‐


−N symbolname

−−strip−symbol=symbolname
    Do not copy symbol symbolname from the source file.
    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.

−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 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.









                             ‐5‐


−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









                             ‐6‐


    −−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









                             ‐7‐


    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.











                             ‐8‐


−−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.

−−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.

−−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.

−−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









                             ‐9‐


    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.

−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.

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

Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000,
2001, 2002 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".