objcopy(1)
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]
[--strip-unneeded]
[-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]
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[--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]
[--no-merge-notes]
[-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
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translation work; it has access to all the formats described
in BFD and thus is able to recognize most formats without
being told explicitly.
objcopy can be used to generate S-records by using an output
target of srec (e.g., use -O srec).
objcopy can be used to generate a raw binary file by using
an output target of binary (e.g., use -O binary). When
objcopy generates a raw binary file, it will essentially
produce a memory dump of the contents of the input object
file. All symbols and relocation information will be
discarded. The memory dump will start at the load address
of the lowest section copied into the output file.
When generating an S-record or a raw binary file, it may be
helpful to use -S to remove sections containing debugging
information. In some cases -R will be useful to remove
sections which contain information that is not needed by the
binary file.
Note---objcopy is not able to change the endianness of its
input files. If the input format has an endianness (some
formats do not), objcopy can only copy the inputs into file
formats that have the same endianness or which have no
endianness (e.g., srec). (However, see the --reverse-bytes
option.)
OPTIONS
infile
outfile
The input and output files, respectively. If you do not
specify outfile, objcopy creates a temporary file and
destructively renames the result with the name of
infile.
-I bfdname
--input-target=bfdname
Consider the source file's object format to be bfdname,
rather than attempting to deduce it.
-O bfdname
--output-target=bfdname
Write the output file using the object format bfdname.
-F bfdname
--target=bfdname
Use bfdname as the object format for both the input and
the output file; i.e., simply transfer data from source
to destination with no translation.
-B bfdarch
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--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
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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
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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
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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
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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
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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.
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--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
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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 using 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
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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
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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
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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.
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--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."
executable"
"* A sub-directory of the directory containing the
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.
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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:
called>
1.<Link the executable as normal. Assuming that is is
"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
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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
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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
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symbol type to "STT_COMMON". --elf-stt-common=no
converts common symbol type to "STT_OBJECT".
--merge-notes
--no-merge-notes
For ELF files, attempt (or do not 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
ld(1), objdump(1), and the Info entries for binutils.
COPYRIGHT
Copyright (c) 1991-2018 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
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of the license is included in the section entitled "GNU Free
Documentation License".
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