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objcopy

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]
	       [-G symbolname|--keep-global-symbol=symbolname]
	       [-L symbolname|--localize-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]
	       [--srec-len=ival] [--srec-forceS3]
	       [--redefine-sym old=new]
	       [--redefine-syms=filename]
	       [--weaken]
	       [--keep-symbols=filename]
	       [--strip-symbols=filename]
	       [--keep-global-symbols=filename]
	       [--localize-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]
	       [--only-keep-debug]
	       [--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	recog-
       nize 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  endian-
       ness or which have no endianness (e.g., srec).

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
	   Copy  only symbol symbolname from the source file.  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.

       -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.

       -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 sym-
	   bol name.  If the first character of the symbol name is the	excla-
	   mation  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 for-
	   mats 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.	Other-
	   wise, 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 sec-
	   tion address is set to val.	Otherwise, val is  added  to  or  sub-
	   tracted   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-sec-
	   tion-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  -B  \
		      --rename-section .data=.rodata,alloc,load,readonly,data,contents \
		       

       --change-leading-char
	   Some object file formats use special characters  at	the  start  of
	   symbols.   The most common such character is underscore, which com-
	   pilers 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 lead-
	   ing 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 differ-
	   ent 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.

       --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 charac-
	   ter.  This option may be given more than once.

       --weaken
	   Change all global symbols in the file to be weak.  This can be use-
	   ful 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 sym-
	   bols.

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

       --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.

       --only-keep-debug
	   Strip a file, removing any  sections  that  would  be  stripped  by
	   --strip-debug and leaving the debugging sections.

	   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 dis-
	   tribution and the second a debugging information file which is only
	   needed  if  debugging abilities are required.  The suggested proce-
	   dure to create these files is as follows:

	   1.
	       "foo" then...

	   1.
	       create a file containing the debugging info.

	   1.
	       stripped executable.

	   1.
	       to add a link to the debugging  info  into  the	stripped  exe-
	       cutable.

	   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.
	   1.
	   1.
	   1.

	   ie  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.

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

       -v
       --verbose
	   Verbose output: list all object files modified.  In the case of ar-
	   chives, 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	avail-
	   able.

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

COPYRIGHT
       Copyright  (c)  1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002,
       2003 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-2.14.91		  2004-04-09			    OBJCOPY(1)