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

OBJCOPY(1)                  GNU Development Tools                 OBJCOPY(1)

NAME         top

       objcopy - copy and translate object files

SYNOPSIS         top

       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 [breadth]|--interleave[=breadth]]
               [--interleave-width=width]
               [-j sectionpattern|--only-section=sectionpattern]
               [-R sectionpattern|--remove-section=sectionpattern]
               [--remove-relocations=sectionpattern]
               [-p|--preserve-dates]
               [-D|--enable-deterministic-archives]
               [-U|--disable-deterministic-archives]
               [--debugging]
               [--gap-fill=val]
               [--pad-to=address]
               [--set-start=val]
               [--adjust-start=incr]
               [--change-addresses=incr]
               [--change-section-address sectionpattern{=,+,-}val]
               [--change-section-lma sectionpattern{=,+,-}val]
               [--change-section-vma sectionpattern{=,+,-}val]
               [--change-warnings] [--no-change-warnings]
               [--set-section-flags sectionpattern=flags]
               [--add-section sectionname=filename]
               [--dump-section sectionname=filename]
               [--update-section sectionname=filename]
               [--rename-section oldname=newname[,flags]]
               [--long-section-names {enable,disable,keep}]
               [--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]
               [--add-symbol name=[section:]value[,flags]
               [--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]
               [--strip-dwo]
               [--extract-dwo]
               [--extract-symbol]
               [--writable-text]
               [--readonly-text]
               [--pure]
               [--impure]
               [--file-alignment=num]
               [--heap=size]
               [--image-base=address]
               [--section-alignment=num]
               [--stack=size]
               [--subsystem=which:major.minor]
               [--compress-debug-sections]
               [--decompress-debug-sections]
               [--elf-stt-common=val]
               [--merge-notes]
               [-v|--verbose]
               [-V|--version]
               [--help] [--info]
               infile [outfile]

DESCRIPTION         top

       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         top

       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 architecture-less 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 sectionpattern
       --only-section=sectionpattern
           Copy only the indicated sections 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.  Wildcard characters are accepted in sectionpattern.

           If the first character of sectionpattern is the exclamation point
           (!) then matching sections will not be copied, even if earlier
           use of --only-section on the same command line would otherwise
           copy it.  For example:

                     --only-section=.text.* --only-section=!.text.foo

           will copy all sectinos maching '.text.*' but not the section
           '.text.foo'.

       -R sectionpattern
       --remove-section=sectionpattern
           Remove any section matching sectionpattern from the output file.
           This option may be given more than once.  Note that using this
           option inappropriately may make the output file unusable.
           Wildcard characters are accepted in sectionpattern.  Using both
           the -j and -R options together results in undefined behaviour.

           If the first character of sectionpattern is the exclamation point
           (!) then matching sections will not be removed even if an earlier
           use of --remove-section on the same command line would otherwise
           remove it.  For example:

                     --remove-section=.text.* --remove-section=!.text.foo

           will remove all sections matching the pattern '.text.*', but will
           not remove the section '.text.foo'.

       --remove-relocations=sectionpattern
           Remove relocations from the output file for any section matching
           sectionpattern.  This option may be given more than once.  Note
           that using this option inappropriately may make the output file
           unusable.  Wildcard characters are accepted in sectionpattern.
           For example:

                     --remove-relocations=.text.*

           will remove the relocations for all sections matching the patter
           '.text.*'.

           If the first character of sectionpattern is the exclamation point
           (!) then matching sections will not have their relocation removed
           even if an earlier use of --remove-relocations on the same
           command line would otherwise cause the relocations to be removed.
           For example:

                     --remove-relocations=.text.* --remove-relocations=!.text.foo

           will remove all relocations for sections matching the pattern
           '.text.*', but will not remove relocations for the section
           '.text.foo'.

       -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
           Convert a global or weak symbol called symbolname into a local
           symbol, so that it is not visible externally.  This option may be
           given more than once.  Note - unique symbols are not converted.

       -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
           If interleaving has been enabled via the --interleave option then
           start the range of bytes to keep at the byteth byte.  byte can be
           in the range from 0 to breadth-1, where breadth is the value
           given by the --interleave option.

       -i [breadth]
       --interleave[=breadth]
           Only copy a range out of every breadth bytes.  (Header data is
           not affected).  Select which byte in the range begins the copy
           with the --byte option.  Select the width of the range with the
           --interleave-width option.

           This option is useful for creating files to program ROM.  It is
           typically used with an "srec" output target.  Note that objcopy
           will complain if you do not specify the --byte option as well.

           The default interleave breadth is 4, so with --byte set to 0,
           objcopy would copy the first byte out of every four bytes from
           the input to the output.

       --interleave-width=width
           When used with the --interleave option, copy width bytes at a
           time.  The start of the range of bytes to be copied is set by the
           --byte option, and the extent of the range is set with the
           --interleave option.

           The default value for this option is 1.  The value of width plus
           the byte value set by the --byte option must not exceed the
           interleave breadth set by the --interleave option.

           This option can be used to create images for two 16-bit flashes
           interleaved in a 32-bit bus by passing -b 0 -i 4
           --interleave-width=2 and -b 2 -i 4 --interleave-width=2 to two
           objcopy commands.  If the input was '12345678' then the outputs
           would be '1256' and '3478' respectively.

       -p
       --preserve-dates
           Set the access and modification dates of the output file to be
           the same as those of the input file.

       -D
       --enable-deterministic-archives
           Operate in deterministic mode.  When copying archive members and
           writing the archive index, use zero for UIDs, GIDs, timestamps,
           and use consistent file modes for all files.

           If binutils was configured with --enable-deterministic-archives,
           then this mode is on by default.  It can be disabled with the -U
           option, below.

       -U
       --disable-deterministic-archives
           Do not operate in deterministic mode.  This is the inverse of the
           -D option, above: when copying archive members and writing the
           archive index, use their actual UID, GID, timestamp, and file
           mode values.

           This is the default unless binutils was configured with
           --enable-deterministic-archives.

       --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 sectionpattern{=,+,-}val
       --adjust-section-vma sectionpattern{=,+,-}val
           Set or change both the VMA address and the LMA address of any
           section matching sectionpattern.  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 sectionpattern does not match any
           sections in the input file, a warning will be issued, unless
           --no-change-warnings is used.

       --change-section-lma sectionpattern{=,+,-}val
           Set or change the LMA address of any sections matching
           sectionpattern.  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 sectionpattern does
           not match any sections in the input file, a warning will be
           issued, unless --no-change-warnings is used.

       --change-section-vma sectionpattern{=,+,-}val
           Set or change the VMA address of any section matching
           sectionpattern.  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
           sectionpattern does not match any sections 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 section pattern does not
           match any sections, 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
           section pattern does not match any sections.

       --set-section-flags sectionpattern=flags
           Set the flags for any sections matching sectionpattern.  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.  Note - it may be necessary to use the
           --set-section-flags option to set the attributes of the newly
           created section.

       --dump-section sectionname=filename
           Place the contents of section named sectionname into the file
           filename, overwriting any contents that may have been there
           previously.  This option is the inverse of --add-section.  This
           option is similar to the --only-section option except that it
           does not create a formatted file, it just dumps the contents as
           raw binary data, without applying any relocations.  The option
           can be specified more than once.

       --update-section sectionname=filename
           Replace the existing contents of a section named sectionname with
           the contents of file filename.  The size of the section will be
           adjusted to the size of the file.  The section flags for
           sectionname will be unchanged.  For ELF format files the section
           to segment mapping will also remain unchanged, something which is
           not possible using --remove-section followed by --add-section.
           The option can be specified more than once.

           Note - it is possible to use --rename-section and
           --update-section to both update and rename a section from one
           command line.  In this case, pass the original section name to
           --update-section, and the original and new section names to
           --rename-section.

       --add-symbol name=[section:]value[,flags]
           Add a new symbol named name while copying the file.  This option
           may be specified multiple times.  If the section is given, the
           symbol will be associated with and relative to that section,
           otherwise it will be an ABS symbol.  Specifying an undefined
           section will result in a fatal error.  There is no check for the
           value, it will be taken as specified.  Symbol flags can be
           specified and not all flags will be meaningful for all object
           file formats.  By default, the symbol will be global.  The
           special flag 'before=othersym' will insert the new symbol in
           front of the specified othersym, otherwise the symbol(s) will be
           added at the end of the symbol table in the order they appear.

       --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>

       --long-section-names {enable,disable,keep}
           Controls the handling of long section names when processing
           "COFF" and "PE-COFF" object formats.  The default behaviour,
           keep, is to preserve long section names if any are present in the
           input file.  The enable and disable options forcibly enable or
           disable the use of long section names in the output object; when
           disable is in effect, any long section names in the input object
           will be truncated.  The enable option will only emit long section
           names if any are present in the inputs; this is mostly the same
           as keep, but it is left undefined whether the enable option might
           force the creation of an empty string table in the output 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.  Note: the file at
           path-to-file must exist.  Part of the process of adding the
           .gnu_debuglink section involves embedding a checksum of the
           contents of the debug info file into the section.

           If the debug info file is built in one location but it is going
           to be installed at a later time into a different location then do
           not use the path to the installed location.  The
           --add-gnu-debuglink option will fail because the installed file
           does not exist yet.  Instead put the debug info file in the
           current directory and use the --add-gnu-debuglink option without
           any directory components, like this:

                    objcopy --add-gnu-debuglink=foo.debug

           At debug time the debugger will attempt to look for the separate
           debug info file in a set of known locations.  The exact set of
           these locations varies depending upon the distribution being
           used, but it typically includes:

           "* The same directory as the executable."
           "* A sub-directory of the directory containing the executable"
               called .debug

           "* A global debug directory such as /usr/lib/debug."

           As long as the debug info file has been installed into one of
           these locations before the debugger is run everything should work
           correctly.

       --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.

           Note - the section headers of the stripped sections are
           preserved, including their sizes, but the contents of the section
           are discarded.  The section headers are preserved so that other
           tools can match up the debuginfo file with the real executable,
           even if that executable has been relocated to a different address
           space.

           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 is 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.

       --strip-dwo
           Remove the contents of all DWARF .dwo sections, leaving the
           remaining debugging sections and all symbols intact.  This option
           is intended for use by the compiler as part of the -gsplit-dwarf
           option, which splits debug information between the .o file and a
           separate .dwo file.  The compiler generates all debug information
           in the same file, then uses the --extract-dwo option to copy the
           .dwo sections to the .dwo file, then the --strip-dwo option to
           remove those sections from the original .o file.

       --extract-dwo
           Extract the contents of all DWARF .dwo sections.  See the
           --strip-dwo option for more information.

       --file-alignment num
           Specify the file alignment.  Sections in the file will always
           begin at file offsets which are multiples of this number.  This
           defaults to 512.  [This option is specific to PE targets.]

       --heap reserve
       --heap reserve,commit
           Specify the number of bytes of memory to reserve (and optionally
           commit) to be used as heap for this program.  [This option is
           specific to PE targets.]

       --image-base value
           Use value as the base address of your program or dll.  This is
           the lowest memory location that will be used when your program or
           dll is loaded.  To reduce the need to relocate and improve
           performance of your dlls, each should have a unique base address
           and not overlap any other dlls.  The default is 0x400000 for
           executables, and 0x10000000 for dlls.  [This option is specific
           to PE targets.]

       --section-alignment num
           Sets the section alignment.  Sections in memory will always begin
           at addresses which are a multiple of this number.  Defaults to
           0x1000.  [This option is specific to PE targets.]

       --stack reserve
       --stack reserve,commit
           Specify the number of bytes of memory to reserve (and optionally
           commit) to be used as stack for this program.  [This option is
           specific to PE targets.]

       --subsystem which
       --subsystem which:major
       --subsystem which:major.minor
           Specifies the subsystem under which your program will execute.
           The legal values for which are "native", "windows", "console",
           "posix", "efi-app", "efi-bsd", "efi-rtd", "sal-rtd", and "xbox".
           You may optionally set the subsystem version also.  Numeric
           values are also accepted for which.  [This option is specific to
           PE targets.]

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

           *<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.

       --compress-debug-sections
           Compress DWARF debug sections using zlib with SHF_COMPRESSED from
           the ELF ABI.  Note - if compression would actually make a section
           larger, then it is not compressed.

       --compress-debug-sections=none
       --compress-debug-sections=zlib
       --compress-debug-sections=zlib-gnu
       --compress-debug-sections=zlib-gabi
           For ELF files, these options control how DWARF debug sections are
           compressed.  --compress-debug-sections=none is equivalent to
           --decompress-debug-sections.  --compress-debug-sections=zlib and
           --compress-debug-sections=zlib-gabi are equivalent to
           --compress-debug-sections.  --compress-debug-sections=zlib-gnu
           compresses DWARF debug sections using zlib.  The debug sections
           are renamed to begin with .zdebug instead of .debug.  Note - if
           compression would actually make a section larger, then it is not
           compressed nor renamed.

       --decompress-debug-sections
           Decompress DWARF debug sections using zlib.  The original section
           names of the compressed sections are restored.

       --elf-stt-common=yes
       --elf-stt-common=no
           For ELF files, these options control whether common symbols
           should be converted to the "STT_COMMON" or "STT_OBJECT" type.
           --elf-stt-common=yes converts common symbol type to "STT_COMMON".
           --elf-stt-common=no converts common symbol type to "STT_OBJECT".

       --merge-notes
           For ELF files, attempt to reduce the size of any SHT_NOTE type
           sections by removing duplicate notes.

       -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         top

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

COPYRIGHT         top

       Copyright (c) 1991-2017 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 1.3 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".

COLOPHON         top

       This page is part of the binutils (a collection of tools for working
       with executable binaries) project.  Information about the project can
       be found at ⟨http://www.gnu.org/software/binutils/⟩.  If you have a
       bug report for this manual page, see 
       ⟨http://sourceware.org/bugzilla/enter_bug.cgi?product=binutils⟩.  This
       page was obtained from the project's upstream Git repository 
       ⟨git://sourceware.org/git/binutils-gdb.git⟩ on 2017-03-13.  If you
       discover any rendering problems in this HTML version of the page, or
       you believe there is a better or more up-to-date source for the page,
       or you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

binutils-2.28.51                 2017-03-12                       OBJCOPY(1)