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 [
breadth]|
--interleave[=
breadth]]
[
--interleave-width=width]
[
-j sectionpattern|
--only-section=sectionpattern]
[
-R
sectionpattern|
--remove-section=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]
[
-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 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
- --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.
- -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.
- -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 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".
- -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) 1991-2016 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".