objcopy man page on aLinux

Man page or keyword search:  
man Server   7435 pages
apropos Keyword Search (all sections)
Output format
aLinux logo
[printable version]

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	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).  (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 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 <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  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.

       --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 problem‐
	   atic 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  out‐
	   put 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 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.

       --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 charac‐
	   ter.	 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 out‐
	   put.

	   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.<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  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.<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	debug‐
	   ging information may be incomplete.	Besides the gnu_debuglink fea‐
	   ture currently only supports the presence of one filename  contain‐
	   ing	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 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.

       @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  charac‐
	   ter	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  Founda‐
       tion, 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-2.17.90		  2007-08-06			    OBJCOPY(1)
[top]

List of man pages available for aLinux

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net