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<a name="objcopy"></a>
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<p>
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Next: <a rel="next" accesskey="n" href="objdump.html#objdump">objdump</a>,
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Previous: <a rel="previous" accesskey="p" href="nm.html#nm">nm</a>,
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Up: <a rel="up" accesskey="u" href="index.html#Top">Top</a>
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<h2 class="chapter">3 objcopy</h2>
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<!-- man title objcopy copy and translate object files -->
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<pre class="smallexample"> <!-- man begin SYNOPSIS objcopy -->
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objcopy [<samp><span class="option">-F</span></samp> <var>bfdname</var>|<samp><span class="option">--target=</span></samp><var>bfdname</var>]
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[<samp><span class="option">-I</span></samp> <var>bfdname</var>|<samp><span class="option">--input-target=</span></samp><var>bfdname</var>]
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[<samp><span class="option">-O</span></samp> <var>bfdname</var>|<samp><span class="option">--output-target=</span></samp><var>bfdname</var>]
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[<samp><span class="option">-B</span></samp> <var>bfdarch</var>|<samp><span class="option">--binary-architecture=</span></samp><var>bfdarch</var>]
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[<samp><span class="option">-S</span></samp>|<samp><span class="option">--strip-all</span></samp>]
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[<samp><span class="option">-g</span></samp>|<samp><span class="option">--strip-debug</span></samp>]
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[<samp><span class="option">--strip-unneeded</span></samp>]
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[<samp><span class="option">-K</span></samp> <var>symbolname</var>|<samp><span class="option">--keep-symbol=</span></samp><var>symbolname</var>]
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[<samp><span class="option">-N</span></samp> <var>symbolname</var>|<samp><span class="option">--strip-symbol=</span></samp><var>symbolname</var>]
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[<samp><span class="option">--strip-unneeded-symbol=</span></samp><var>symbolname</var>]
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[<samp><span class="option">-G</span></samp> <var>symbolname</var>|<samp><span class="option">--keep-global-symbol=</span></samp><var>symbolname</var>]
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[<samp><span class="option">--localize-hidden</span></samp>]
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[<samp><span class="option">-L</span></samp> <var>symbolname</var>|<samp><span class="option">--localize-symbol=</span></samp><var>symbolname</var>]
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[<samp><span class="option">--globalize-symbol=</span></samp><var>symbolname</var>]
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[<samp><span class="option">--globalize-symbols=</span></samp><var>filename</var>]
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[<samp><span class="option">-W</span></samp> <var>symbolname</var>|<samp><span class="option">--weaken-symbol=</span></samp><var>symbolname</var>]
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[<samp><span class="option">-w</span></samp>|<samp><span class="option">--wildcard</span></samp>]
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[<samp><span class="option">-x</span></samp>|<samp><span class="option">--discard-all</span></samp>]
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[<samp><span class="option">-X</span></samp>|<samp><span class="option">--discard-locals</span></samp>]
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[<samp><span class="option">-b</span></samp> <var>byte</var>|<samp><span class="option">--byte=</span></samp><var>byte</var>]
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[<samp><span class="option">-i</span></samp> [<var>breadth</var>]|<samp><span class="option">--interleave</span></samp>[=<var>breadth</var>]]
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[<samp><span class="option">--interleave-width=</span></samp><var>width</var>]
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[<samp><span class="option">-j</span></samp> <var>sectionpattern</var>|<samp><span class="option">--only-section=</span></samp><var>sectionpattern</var>]
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[<samp><span class="option">-R</span></samp> <var>sectionpattern</var>|<samp><span class="option">--remove-section=</span></samp><var>sectionpattern</var>]
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[<samp><span class="option">--remove-relocations=</span></samp><var>sectionpattern</var>]
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[<samp><span class="option">-p</span></samp>|<samp><span class="option">--preserve-dates</span></samp>]
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[<samp><span class="option">-D</span></samp>|<samp><span class="option">--enable-deterministic-archives</span></samp>]
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[<samp><span class="option">-U</span></samp>|<samp><span class="option">--disable-deterministic-archives</span></samp>]
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[<samp><span class="option">--debugging</span></samp>]
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[<samp><span class="option">--gap-fill=</span></samp><var>val</var>]
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[<samp><span class="option">--pad-to=</span></samp><var>address</var>]
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[<samp><span class="option">--set-start=</span></samp><var>val</var>]
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[<samp><span class="option">--adjust-start=</span></samp><var>incr</var>]
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[<samp><span class="option">--change-addresses=</span></samp><var>incr</var>]
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[<samp><span class="option">--change-section-address</span></samp> <var>sectionpattern</var>{=,+,-}<var>val</var>]
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[<samp><span class="option">--change-section-lma</span></samp> <var>sectionpattern</var>{=,+,-}<var>val</var>]
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[<samp><span class="option">--change-section-vma</span></samp> <var>sectionpattern</var>{=,+,-}<var>val</var>]
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[<samp><span class="option">--change-warnings</span></samp>] [<samp><span class="option">--no-change-warnings</span></samp>]
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[<samp><span class="option">--set-section-flags</span></samp> <var>sectionpattern</var>=<var>flags</var>]
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[<samp><span class="option">--set-section-alignment</span></samp> <var>sectionpattern</var>=<var>align</var>]
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[<samp><span class="option">--add-section</span></samp> <var>sectionname</var>=<var>filename</var>]
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[<samp><span class="option">--dump-section</span></samp> <var>sectionname</var>=<var>filename</var>]
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[<samp><span class="option">--update-section</span></samp> <var>sectionname</var>=<var>filename</var>]
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[<samp><span class="option">--rename-section</span></samp> <var>oldname</var>=<var>newname</var>[,<var>flags</var>]]
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[<samp><span class="option">--long-section-names</span></samp> {enable,disable,keep}]
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[<samp><span class="option">--change-leading-char</span></samp>] [<samp><span class="option">--remove-leading-char</span></samp>]
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[<samp><span class="option">--reverse-bytes=</span></samp><var>num</var>]
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[<samp><span class="option">--srec-len=</span></samp><var>ival</var>] [<samp><span class="option">--srec-forceS3</span></samp>]
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[<samp><span class="option">--redefine-sym</span></samp> <var>old</var>=<var>new</var>]
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[<samp><span class="option">--redefine-syms=</span></samp><var>filename</var>]
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[<samp><span class="option">--weaken</span></samp>]
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[<samp><span class="option">--keep-symbols=</span></samp><var>filename</var>]
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[<samp><span class="option">--strip-symbols=</span></samp><var>filename</var>]
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[<samp><span class="option">--strip-unneeded-symbols=</span></samp><var>filename</var>]
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[<samp><span class="option">--keep-global-symbols=</span></samp><var>filename</var>]
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[<samp><span class="option">--localize-symbols=</span></samp><var>filename</var>]
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[<samp><span class="option">--weaken-symbols=</span></samp><var>filename</var>]
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[<samp><span class="option">--add-symbol</span></samp> <var>name</var>=[<var>section</var>:]<var>value</var>[,<var>flags</var>]]
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[<samp><span class="option">--alt-machine-code=</span></samp><var>index</var>]
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[<samp><span class="option">--prefix-symbols=</span></samp><var>string</var>]
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[<samp><span class="option">--prefix-sections=</span></samp><var>string</var>]
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[<samp><span class="option">--prefix-alloc-sections=</span></samp><var>string</var>]
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[<samp><span class="option">--add-gnu-debuglink=</span></samp><var>path-to-file</var>]
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[<samp><span class="option">--keep-file-symbols</span></samp>]
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[<samp><span class="option">--only-keep-debug</span></samp>]
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[<samp><span class="option">--strip-dwo</span></samp>]
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[<samp><span class="option">--extract-dwo</span></samp>]
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[<samp><span class="option">--extract-symbol</span></samp>]
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[<samp><span class="option">--writable-text</span></samp>]
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[<samp><span class="option">--readonly-text</span></samp>]
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[<samp><span class="option">--pure</span></samp>]
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[<samp><span class="option">--impure</span></samp>]
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[<samp><span class="option">--file-alignment=</span></samp><var>num</var>]
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[<samp><span class="option">--heap=</span></samp><var>size</var>]
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[<samp><span class="option">--image-base=</span></samp><var>address</var>]
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[<samp><span class="option">--section-alignment=</span></samp><var>num</var>]
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[<samp><span class="option">--stack=</span></samp><var>size</var>]
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[<samp><span class="option">--subsystem=</span></samp><var>which</var>:<var>major</var>.<var>minor</var>]
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[<samp><span class="option">--compress-debug-sections</span></samp>]
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[<samp><span class="option">--decompress-debug-sections</span></samp>]
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[<samp><span class="option">--elf-stt-common=</span><var>val</var></samp>]
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[<samp><span class="option">--merge-notes</span></samp>]
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[<samp><span class="option">--no-merge-notes</span></samp>]
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[<samp><span class="option">--verilog-data-width=</span><var>val</var></samp>]
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[<samp><span class="option">-v</span></samp>|<samp><span class="option">--verbose</span></samp>]
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[<samp><span class="option">-V</span></samp>|<samp><span class="option">--version</span></samp>]
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[<samp><span class="option">--help</span></samp>] [<samp><span class="option">--info</span></samp>]
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<var>infile</var> [<var>outfile</var>]
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<!-- man end -->
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</pre>
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<!-- man begin DESCRIPTION objcopy -->
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<p>The <span class="sc">gnu</span> <samp><span class="command">objcopy</span></samp> utility copies the contents of an object
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file to another. <samp><span class="command">objcopy</span></samp> uses the <span class="sc">gnu</span> <span class="sc">bfd</span> Library to
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read and write the object files. It can write the destination object
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file in a format different from that of the source object file. The
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exact behavior of <samp><span class="command">objcopy</span></samp> is controlled by command-line options.
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Note that <samp><span class="command">objcopy</span></samp> should be able to copy a fully linked file
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between any two formats. However, copying a relocatable object file
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between any two formats may not work as expected.
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<p><samp><span class="command">objcopy</span></samp> creates temporary files to do its translations and
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deletes them afterward. <samp><span class="command">objcopy</span></samp> uses <span class="sc">bfd</span> to do all its
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translation work; it has access to all the formats described in <span class="sc">bfd</span>
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and thus is able to recognize most formats without being told
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explicitly. See <a href="../ld/BFD.html#BFD">BFD</a>.
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<p><samp><span class="command">objcopy</span></samp> can be used to generate S-records by using an output
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target of ‘<samp><span class="samp">srec</span></samp>’ (e.g., use ‘<samp><span class="samp">-O srec</span></samp>’).
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<p><samp><span class="command">objcopy</span></samp> can be used to generate a raw binary file by using an
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output target of ‘<samp><span class="samp">binary</span></samp>’ (e.g., use <samp><span class="option">-O binary</span></samp>). When
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<samp><span class="command">objcopy</span></samp> generates a raw binary file, it will essentially produce
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a memory dump of the contents of the input object file. All symbols and
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relocation information will be discarded. The memory dump will start at
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the load address of the lowest section copied into the output file.
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<p>When generating an S-record or a raw binary file, it may be helpful to
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use <samp><span class="option">-S</span></samp> to remove sections containing debugging information. In
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some cases <samp><span class="option">-R</span></samp> will be useful to remove sections which contain
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information that is not needed by the binary file.
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<p>Note—<samp><span class="command">objcopy</span></samp> is not able to change the endianness of its input
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files. If the input format has an endianness (some formats do not),
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<samp><span class="command">objcopy</span></samp> can only copy the inputs into file formats that have the
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same endianness or which have no endianness (e.g., ‘<samp><span class="samp">srec</span></samp>’).
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(However, see the <samp><span class="option">--reverse-bytes</span></samp> option.)
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<!-- man end -->
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<!-- man begin OPTIONS objcopy -->
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<dl>
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<dt><samp><var>infile</var></samp><dt><samp><var>outfile</var></samp><dd>The input and output files, respectively.
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If you do not specify <var>outfile</var>, <samp><span class="command">objcopy</span></samp> creates a
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temporary file and destructively renames the result with
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the name of <var>infile</var>.
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<br><dt><samp><span class="env">-I </span><var>bfdname</var></samp><dt><samp><span class="env">--input-target=</span><var>bfdname</var></samp><dd>Consider the source file's object format to be <var>bfdname</var>, rather than
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attempting to deduce it. See <a href="Target-Selection.html#Target-Selection">Target Selection</a>, for more information.
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<br><dt><samp><span class="env">-O </span><var>bfdname</var></samp><dt><samp><span class="env">--output-target=</span><var>bfdname</var></samp><dd>Write the output file using the object format <var>bfdname</var>.
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See <a href="Target-Selection.html#Target-Selection">Target Selection</a>, for more information.
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<br><dt><samp><span class="env">-F </span><var>bfdname</var></samp><dt><samp><span class="env">--target=</span><var>bfdname</var></samp><dd>Use <var>bfdname</var> as the object format for both the input and the output
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file; i.e., simply transfer data from source to destination with no
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translation. See <a href="Target-Selection.html#Target-Selection">Target Selection</a>, for more information.
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<br><dt><samp><span class="env">-B </span><var>bfdarch</var></samp><dt><samp><span class="env">--binary-architecture=</span><var>bfdarch</var></samp><dd>Useful when transforming a architecture-less input file into an object file.
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In this case the output architecture can be set to <var>bfdarch</var>. This
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option will be ignored if the input file has a known <var>bfdarch</var>. You
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can access this binary data inside a program by referencing the special
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symbols that are created by the conversion process. These symbols are
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called _binary_<var>objfile</var>_start, _binary_<var>objfile</var>_end and
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_binary_<var>objfile</var>_size. e.g. you can transform a picture file into
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an object file and then access it in your code using these symbols.
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<br><dt><samp><span class="env">-j </span><var>sectionpattern</var></samp><dt><samp><span class="env">--only-section=</span><var>sectionpattern</var></samp><dd>Copy only the indicated sections from the input file to the output file.
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This option may be given more than once. Note that using this option
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inappropriately may make the output file unusable. Wildcard
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characters are accepted in <var>sectionpattern</var>.
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<p>If the first character of <var>sectionpattern</var> is the exclamation
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point (!) then matching sections will not be copied, even if earlier
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use of <samp><span class="option">--only-section</span></samp> on the same command line would
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otherwise copy it. For example:
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<pre class="smallexample"> --only-section=.text.* --only-section=!.text.foo
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</pre>
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<p>will copy all sectinos maching '.text.*' but not the section
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'.text.foo'.
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<br><dt><samp><span class="env">-R </span><var>sectionpattern</var></samp><dt><samp><span class="env">--remove-section=</span><var>sectionpattern</var></samp><dd>Remove any section matching <var>sectionpattern</var> from the output file.
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This option may be given more than once. Note that using this option
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inappropriately may make the output file unusable. Wildcard
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characters are accepted in <var>sectionpattern</var>. Using both the
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<samp><span class="option">-j</span></samp> and <samp><span class="option">-R</span></samp> options together results in undefined
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behaviour.
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<p>If the first character of <var>sectionpattern</var> is the exclamation
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point (!) then matching sections will not be removed even if an
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earlier use of <samp><span class="option">--remove-section</span></samp> on the same command line
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would otherwise remove it. For example:
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<pre class="smallexample"> --remove-section=.text.* --remove-section=!.text.foo
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</pre>
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<p>will remove all sections matching the pattern '.text.*', but will not
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remove the section '.text.foo'.
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<br><dt><samp><span class="env">--remove-relocations=</span><var>sectionpattern</var></samp><dd>Remove non-dynamic relocations from the output file for any section
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matching <var>sectionpattern</var>. This option may be given more than
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once. Note that using this option inappropriately may make the output
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file unusable, and attempting to remove a dynamic relocation section
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such as ‘<samp><span class="samp">.rela.plt</span></samp>’ from an executable or shared library with
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<samp><span class="option">--remove-relocations=.plt</span></samp> will not work. Wildcard characters
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are accepted in <var>sectionpattern</var>.
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For example:
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<pre class="smallexample"> --remove-relocations=.text.*
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</pre>
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<p>will remove the relocations for all sections matching the pattern
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'.text.*'.
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<p>If the first character of <var>sectionpattern</var> is the exclamation
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point (!) then matching sections will not have their relocation
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removed even if an earlier use of <samp><span class="option">--remove-relocations</span></samp> on the
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same command line would otherwise cause the relocations to be removed.
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For example:
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<pre class="smallexample"> --remove-relocations=.text.* --remove-relocations=!.text.foo
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</pre>
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<p>will remove all relocations for sections matching the pattern
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'.text.*', but will not remove relocations for the section
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'.text.foo'.
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<br><dt><samp><span class="env">-S</span></samp><dt><samp><span class="env">--strip-all</span></samp><dd>Do not copy relocation and symbol information from the source file.
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<br><dt><samp><span class="env">-g</span></samp><dt><samp><span class="env">--strip-debug</span></samp><dd>Do not copy debugging symbols or sections from the source file.
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<br><dt><samp><span class="env">--strip-unneeded</span></samp><dd>Strip all symbols that are not needed for relocation processing.
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<br><dt><samp><span class="env">-K </span><var>symbolname</var></samp><dt><samp><span class="env">--keep-symbol=</span><var>symbolname</var></samp><dd>When stripping symbols, keep symbol <var>symbolname</var> even if it would
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normally be stripped. This option may be given more than once.
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|
|
<br><dt><samp><span class="env">-N </span><var>symbolname</var></samp><dt><samp><span class="env">--strip-symbol=</span><var>symbolname</var></samp><dd>Do not copy symbol <var>symbolname</var> from the source file. This option
|
|
may be given more than once.
|
|
|
|
<br><dt><samp><span class="env">--strip-unneeded-symbol=</span><var>symbolname</var></samp><dd>Do not copy symbol <var>symbolname</var> from the source file unless it is needed
|
|
by a relocation. This option may be given more than once.
|
|
|
|
<br><dt><samp><span class="env">-G </span><var>symbolname</var></samp><dt><samp><span class="env">--keep-global-symbol=</span><var>symbolname</var></samp><dd>Keep only symbol <var>symbolname</var> global. Make all other symbols local
|
|
to the file, so that they are not visible externally. This option may
|
|
be given more than once. Note: this option cannot be used in
|
|
conjunction with the <samp><span class="option">--globalize-symbol</span></samp> or
|
|
<samp><span class="option">--globalize-symbols</span></samp> options.
|
|
|
|
<br><dt><samp><span class="env">--localize-hidden</span></samp><dd>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 <samp><span class="option">-L</span></samp>.
|
|
|
|
<br><dt><samp><span class="env">-L </span><var>symbolname</var></samp><dt><samp><span class="env">--localize-symbol=</span><var>symbolname</var></samp><dd>Convert a global or weak symbol called <var>symbolname</var> 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.
|
|
|
|
<br><dt><samp><span class="env">-W </span><var>symbolname</var></samp><dt><samp><span class="env">--weaken-symbol=</span><var>symbolname</var></samp><dd>Make symbol <var>symbolname</var> weak. This option may be given more than once.
|
|
|
|
<br><dt><samp><span class="env">--globalize-symbol=</span><var>symbolname</var></samp><dd>Give symbol <var>symbolname</var> global scoping so that it is visible
|
|
outside of the file in which it is defined. This option may be given
|
|
more than once. Note: this option cannot be used in conjunction with
|
|
the <samp><span class="option">-G</span></samp> or <samp><span class="option">--keep-global-symbol</span></samp> options.
|
|
|
|
<br><dt><samp><span class="env">-w</span></samp><dt><samp><span class="env">--wildcard</span></samp><dd>Permit regular expressions in <var>symbolname</var>s 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:
|
|
|
|
<pre class="smallexample"> -w -W !foo -W fo*
|
|
</pre>
|
|
<p>would cause objcopy to weaken all symbols that start with “fo”
|
|
except for the symbol “foo”.
|
|
|
|
<br><dt><samp><span class="env">-x</span></samp><dt><samp><span class="env">--discard-all</span></samp><dd>Do not copy non-global symbols from the source file.
|
|
<!-- FIXME any reason to prefer "non-global" to "local" here? -->
|
|
|
|
<br><dt><samp><span class="env">-X</span></samp><dt><samp><span class="env">--discard-locals</span></samp><dd>Do not copy compiler-generated local symbols.
|
|
(These usually start with ‘<samp><span class="samp">L</span></samp>’ or ‘<samp><span class="samp">.</span></samp>’.)
|
|
|
|
<br><dt><samp><span class="env">-b </span><var>byte</var></samp><dt><samp><span class="env">--byte=</span><var>byte</var></samp><dd>If interleaving has been enabled via the <samp><span class="option">--interleave</span></samp> option
|
|
then start the range of bytes to keep at the <var>byte</var>th byte.
|
|
<var>byte</var> can be in the range from 0 to <var>breadth</var>-1, where
|
|
<var>breadth</var> is the value given by the <samp><span class="option">--interleave</span></samp> option.
|
|
|
|
<br><dt><samp><span class="env">-i [</span><var>breadth</var><span class="env">]</span></samp><dt><samp><span class="env">--interleave[=</span><var>breadth</var><span class="env">]</span></samp><dd>Only copy a range out of every <var>breadth</var> bytes. (Header data is
|
|
not affected). Select which byte in the range begins the copy with
|
|
the <samp><span class="option">--byte</span></samp> option. Select the width of the range with the
|
|
<samp><span class="option">--interleave-width</span></samp> option.
|
|
|
|
<p>This option is useful for creating files to program <span class="sc">rom</span>. It is
|
|
typically used with an <code>srec</code> output target. Note that
|
|
<samp><span class="command">objcopy</span></samp> will complain if you do not specify the
|
|
<samp><span class="option">--byte</span></samp> option as well.
|
|
|
|
<p>The default interleave breadth is 4, so with <samp><span class="option">--byte</span></samp> set to 0,
|
|
<samp><span class="command">objcopy</span></samp> would copy the first byte out of every four bytes
|
|
from the input to the output.
|
|
|
|
<br><dt><samp><span class="env">--interleave-width=</span><var>width</var></samp><dd>When used with the <samp><span class="option">--interleave</span></samp> option, copy <var>width</var>
|
|
bytes at a time. The start of the range of bytes to be copied is set
|
|
by the <samp><span class="option">--byte</span></samp> option, and the extent of the range is set with
|
|
the <samp><span class="option">--interleave</span></samp> option.
|
|
|
|
<p>The default value for this option is 1. The value of <var>width</var> plus
|
|
the <var>byte</var> value set by the <samp><span class="option">--byte</span></samp> option must not exceed
|
|
the interleave breadth set by the <samp><span class="option">--interleave</span></samp> option.
|
|
|
|
<p>This option can be used to create images for two 16-bit flashes interleaved
|
|
in a 32-bit bus by passing <samp><span class="option">-b 0 -i 4 --interleave-width=2</span></samp>
|
|
and <samp><span class="option">-b 2 -i 4 --interleave-width=2</span></samp> to two <samp><span class="command">objcopy</span></samp>
|
|
commands. If the input was '12345678' then the outputs would be
|
|
'1256' and '3478' respectively.
|
|
|
|
<br><dt><samp><span class="env">-p</span></samp><dt><samp><span class="env">--preserve-dates</span></samp><dd>Set the access and modification dates of the output file to be the same
|
|
as those of the input file.
|
|
|
|
<br><dt><samp><span class="env">-D</span></samp><dt><samp><span class="env">--enable-deterministic-archives</span></samp><dd><a name="index-deterministic-archives-61"></a><a name="index-g_t_002d_002denable_002ddeterministic_002darchives-62"></a>Operate in <em>deterministic</em> mode. When copying archive members
|
|
and writing the archive index, use zero for UIDs, GIDs, timestamps,
|
|
and use consistent file modes for all files.
|
|
|
|
<p>If <samp><span class="file">binutils</span></samp> was configured with
|
|
<samp><span class="option">--enable-deterministic-archives</span></samp>, then this mode is on by default.
|
|
It can be disabled with the ‘<samp><span class="samp">-U</span></samp>’ option, below.
|
|
|
|
<br><dt><samp><span class="env">-U</span></samp><dt><samp><span class="env">--disable-deterministic-archives</span></samp><dd><a name="index-deterministic-archives-63"></a><a name="index-g_t_002d_002denable_002ddeterministic_002darchives-64"></a>Do <em>not</em> operate in <em>deterministic</em> mode. This is the
|
|
inverse of the <samp><span class="option">-D</span></samp> option, above: when copying archive members
|
|
and writing the archive index, use their actual UID, GID, timestamp,
|
|
and file mode values.
|
|
|
|
<p>This is the default unless <samp><span class="file">binutils</span></samp> was configured with
|
|
<samp><span class="option">--enable-deterministic-archives</span></samp>.
|
|
|
|
<br><dt><samp><span class="env">--debugging</span></samp><dd>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.
|
|
|
|
<br><dt><samp><span class="env">--gap-fill </span><var>val</var></samp><dd>Fill gaps between sections with <var>val</var>. This operation applies to
|
|
the <em>load address</em> (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 <var>val</var>.
|
|
|
|
<br><dt><samp><span class="env">--pad-to </span><var>address</var></samp><dd>Pad the output file up to the load address <var>address</var>. This is
|
|
done by increasing the size of the last section. The extra space is
|
|
filled in with the value specified by <samp><span class="option">--gap-fill</span></samp> (default zero).
|
|
|
|
<br><dt><samp><span class="env">--set-start </span><var>val</var></samp><dd>Set the start address of the new file to <var>val</var>. Not all object file
|
|
formats support setting the start address.
|
|
|
|
<br><dt><samp><span class="env">--change-start </span><var>incr</var></samp><dt><samp><span class="env">--adjust-start </span><var>incr</var></samp><dd><a name="index-changing-start-address-65"></a>Change the start address by adding <var>incr</var>. Not all object file
|
|
formats support setting the start address.
|
|
|
|
<br><dt><samp><span class="env">--change-addresses </span><var>incr</var></samp><dt><samp><span class="env">--adjust-vma </span><var>incr</var></samp><dd><a name="index-changing-object-addresses-66"></a>Change the VMA and LMA addresses of all sections, as well as the start
|
|
address, by adding <var>incr</var>. 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.
|
|
|
|
<br><dt><samp><span class="env">--change-section-address </span><var>sectionpattern</var><span class="env">{=,+,-}</span><var>val</var></samp><dt><samp><span class="env">--adjust-section-vma </span><var>sectionpattern</var><span class="env">{=,+,-}</span><var>val</var></samp><dd><a name="index-changing-section-address-67"></a>Set or change both the VMA address and the LMA address of any section
|
|
matching <var>sectionpattern</var>. If ‘<samp><span class="samp">=</span></samp>’ is used, the section
|
|
address is set to <var>val</var>. Otherwise, <var>val</var> is added to or
|
|
subtracted from the section address. See the comments under
|
|
<samp><span class="option">--change-addresses</span></samp>, above. If <var>sectionpattern</var> does not
|
|
match any sections in the input file, a warning will be issued, unless
|
|
<samp><span class="option">--no-change-warnings</span></samp> is used.
|
|
|
|
<br><dt><samp><span class="env">--change-section-lma </span><var>sectionpattern</var><span class="env">{=,+,-}</span><var>val</var></samp><dd><a name="index-changing-section-LMA-68"></a>Set or change the LMA address of any sections matching
|
|
<var>sectionpattern</var>. 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 ‘<samp><span class="samp">=</span></samp>’
|
|
is used, the section address is set to <var>val</var>. Otherwise,
|
|
<var>val</var> is added to or subtracted from the section address. See the
|
|
comments under <samp><span class="option">--change-addresses</span></samp>, above. If
|
|
<var>sectionpattern</var> does not match any sections in the input file, a
|
|
warning will be issued, unless <samp><span class="option">--no-change-warnings</span></samp> is used.
|
|
|
|
<br><dt><samp><span class="env">--change-section-vma </span><var>sectionpattern</var><span class="env">{=,+,-}</span><var>val</var></samp><dd><a name="index-changing-section-VMA-69"></a>Set or change the VMA address of any section matching
|
|
<var>sectionpattern</var>. 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 ‘<samp><span class="samp">=</span></samp>’ is used, the section address is set to
|
|
<var>val</var>. Otherwise, <var>val</var> is added to or subtracted from the
|
|
section address. See the comments under <samp><span class="option">--change-addresses</span></samp>,
|
|
above. If <var>sectionpattern</var> does not match any sections in the
|
|
input file, a warning will be issued, unless
|
|
<samp><span class="option">--no-change-warnings</span></samp> is used.
|
|
|
|
<br><dt><samp><span class="env">--change-warnings</span></samp><dt><samp><span class="env">--adjust-warnings</span></samp><dd>If <samp><span class="option">--change-section-address</span></samp> or <samp><span class="option">--change-section-lma</span></samp> or
|
|
<samp><span class="option">--change-section-vma</span></samp> is used, and the section pattern does not
|
|
match any sections, issue a warning. This is the default.
|
|
|
|
<br><dt><samp><span class="env">--no-change-warnings</span></samp><dt><samp><span class="env">--no-adjust-warnings</span></samp><dd>Do not issue a warning if <samp><span class="option">--change-section-address</span></samp> or
|
|
<samp><span class="option">--adjust-section-lma</span></samp> or <samp><span class="option">--adjust-section-vma</span></samp> is used, even
|
|
if the section pattern does not match any sections.
|
|
|
|
<br><dt><samp><span class="env">--set-section-flags </span><var>sectionpattern</var><span class="env">=</span><var>flags</var></samp><dd>Set the flags for any sections matching <var>sectionpattern</var>. The
|
|
<var>flags</var> argument is a comma separated string of flag names. The
|
|
recognized names are ‘<samp><span class="samp">alloc</span></samp>’, ‘<samp><span class="samp">contents</span></samp>’, ‘<samp><span class="samp">load</span></samp>’,
|
|
‘<samp><span class="samp">noload</span></samp>’, ‘<samp><span class="samp">readonly</span></samp>’, ‘<samp><span class="samp">code</span></samp>’, ‘<samp><span class="samp">data</span></samp>’, ‘<samp><span class="samp">rom</span></samp>’,
|
|
‘<samp><span class="samp">share</span></samp>’, and ‘<samp><span class="samp">debug</span></samp>’. You can set the ‘<samp><span class="samp">contents</span></samp>’ flag
|
|
for a section which does not have contents, but it is not meaningful
|
|
to clear the ‘<samp><span class="samp">contents</span></samp>’ flag of a section which does have
|
|
contents–just remove the section instead. Not all flags are
|
|
meaningful for all object file formats.
|
|
|
|
<br><dt><samp><span class="env">--set-section-alignment </span><var>sectionpattern</var><span class="env">=</span><var>align</var></samp><dd>Set the alignment for any sections matching <var>sectionpattern</var>.
|
|
<var>align</var> specifies the alignment in bytes and must be a power of
|
|
two, i.e. 1, 2, 4, 8<small class="dots">...</small>.
|
|
|
|
<br><dt><samp><span class="env">--add-section </span><var>sectionname</var><span class="env">=</span><var>filename</var></samp><dd>Add a new section named <var>sectionname</var> while copying the file. The
|
|
contents of the new section are taken from the file <var>filename</var>. 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 <samp><span class="option">--set-section-flags</span></samp>
|
|
option to set the attributes of the newly created section.
|
|
|
|
<br><dt><samp><span class="env">--dump-section </span><var>sectionname</var><span class="env">=</span><var>filename</var></samp><dd>Place the contents of section named <var>sectionname</var> into the file
|
|
<var>filename</var>, overwriting any contents that may have been there
|
|
previously. This option is the inverse of <samp><span class="option">--add-section</span></samp>.
|
|
This option is similar to the <samp><span class="option">--only-section</span></samp> 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.
|
|
|
|
<br><dt><samp><span class="env">--update-section </span><var>sectionname</var><span class="env">=</span><var>filename</var></samp><dd>Replace the existing contents of a section named <var>sectionname</var>
|
|
with the contents of file <var>filename</var>. The size of the section
|
|
will be adjusted to the size of the file. The section flags for
|
|
<var>sectionname</var> will be unchanged. For ELF format files the section
|
|
to segment mapping will also remain unchanged, something which is not
|
|
possible using <samp><span class="option">--remove-section</span></samp> followed by
|
|
<samp><span class="option">--add-section</span></samp>. The option can be specified more than once.
|
|
|
|
<p>Note - it is possible to use <samp><span class="option">--rename-section</span></samp> and
|
|
<samp><span class="option">--update-section</span></samp> to both update and rename a section from one
|
|
command line. In this case, pass the original section name to
|
|
<samp><span class="option">--update-section</span></samp>, and the original and new section names to
|
|
<samp><span class="option">--rename-section</span></samp>.
|
|
|
|
<br><dt><samp><span class="env">--add-symbol </span><var>name</var><span class="env">=[</span><var>section</var><span class="env">:]</span><var>value</var><span class="env">[,</span><var>flags</var><span class="env">]</span></samp><dd>Add a new symbol named <var>name</var> while copying the file. This option may be
|
|
specified multiple times. If the <var>section</var> 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=<var>othersym</var>' will insert the new symbol in front of the specified
|
|
<var>othersym</var>, otherwise the symbol(s) will be added at the end of the
|
|
symbol table in the order they appear.
|
|
|
|
<br><dt><samp><span class="env">--rename-section </span><var>oldname</var><span class="env">=</span><var>newname</var><span class="env">[,</span><var>flags</var><span class="env">]</span></samp><dd>Rename a section from <var>oldname</var> to <var>newname</var>, optionally
|
|
changing the section's flags to <var>flags</var> 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.
|
|
|
|
<p>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:
|
|
|
|
<pre class="smallexample"> objcopy -I binary -O <output_format> -B <architecture> \
|
|
--rename-section .data=.rodata,alloc,load,readonly,data,contents \
|
|
<input_binary_file> <output_object_file>
|
|
</pre>
|
|
<br><dt><samp><span class="env">--long-section-names {enable,disable,keep}</span></samp><dd>Controls the handling of long section names when processing <code>COFF</code>
|
|
and <code>PE-COFF</code> object formats. The default behaviour, ‘<samp><span class="samp">keep</span></samp>’,
|
|
is to preserve long section names if any are present in the input file.
|
|
The ‘<samp><span class="samp">enable</span></samp>’ and ‘<samp><span class="samp">disable</span></samp>’ options forcibly enable or disable
|
|
the use of long section names in the output object; when ‘<samp><span class="samp">disable</span></samp>’
|
|
is in effect, any long section names in the input object will be truncated.
|
|
The ‘<samp><span class="samp">enable</span></samp>’ option will only emit long section names if any are
|
|
present in the inputs; this is mostly the same as ‘<samp><span class="samp">keep</span></samp>’, but it
|
|
is left undefined whether the ‘<samp><span class="samp">enable</span></samp>’ option might force the
|
|
creation of an empty string table in the output file.
|
|
|
|
<br><dt><samp><span class="env">--change-leading-char</span></samp><dd>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 <samp><span class="command">objcopy</span></samp> 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.
|
|
|
|
<br><dt><samp><span class="env">--remove-leading-char</span></samp><dd>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
|
|
<samp><span class="option">--change-leading-char</span></samp> because it always changes the symbol name
|
|
when appropriate, regardless of the object file format of the output
|
|
file.
|
|
|
|
<br><dt><samp><span class="env">--reverse-bytes=</span><var>num</var></samp><dd>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.
|
|
|
|
<p>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.
|
|
|
|
<p>Consider a simple file with a section containing the following eight
|
|
bytes: <code>12345678</code>.
|
|
|
|
<p>Using ‘<samp><span class="samp">--reverse-bytes=2</span></samp>’ for the above example, the bytes in the
|
|
output file would be ordered <code>21436587</code>.
|
|
|
|
<p>Using ‘<samp><span class="samp">--reverse-bytes=4</span></samp>’ for the above example, the bytes in the
|
|
output file would be ordered <code>43218765</code>.
|
|
|
|
<p>By using ‘<samp><span class="samp">--reverse-bytes=2</span></samp>’ for the above example, followed by
|
|
‘<samp><span class="samp">--reverse-bytes=4</span></samp>’ on the output file, the bytes in the second
|
|
output file would be ordered <code>34127856</code>.
|
|
|
|
<br><dt><samp><span class="env">--srec-len=</span><var>ival</var></samp><dd>Meaningful only for srec output. Set the maximum length of the Srecords
|
|
being produced to <var>ival</var>. This length covers both address, data and
|
|
crc fields.
|
|
|
|
<br><dt><samp><span class="env">--srec-forceS3</span></samp><dd>Meaningful only for srec output. Avoid generation of S1/S2 records,
|
|
creating S3-only record format.
|
|
|
|
<br><dt><samp><span class="env">--redefine-sym </span><var>old</var><span class="env">=</span><var>new</var></samp><dd>Change the name of a symbol <var>old</var>, to <var>new</var>. This can be useful
|
|
when one is trying link two things together for which you have no
|
|
source, and there are name collisions.
|
|
|
|
<br><dt><samp><span class="env">--redefine-syms=</span><var>filename</var></samp><dd>Apply <samp><span class="option">--redefine-sym</span></samp> to each symbol pair "<var>old</var> <var>new</var>"
|
|
listed in the file <var>filename</var>. <var>filename</var> 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.
|
|
|
|
<br><dt><samp><span class="env">--weaken</span></samp><dd>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 <samp><span class="option">-R</span></samp> option to the linker. This option is only effective when
|
|
using an object file format which supports weak symbols.
|
|
|
|
<br><dt><samp><span class="env">--keep-symbols=</span><var>filename</var></samp><dd>Apply <samp><span class="option">--keep-symbol</span></samp> option to each symbol listed in the file
|
|
<var>filename</var>. <var>filename</var> 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.
|
|
|
|
<br><dt><samp><span class="env">--strip-symbols=</span><var>filename</var></samp><dd>Apply <samp><span class="option">--strip-symbol</span></samp> option to each symbol listed in the file
|
|
<var>filename</var>. <var>filename</var> 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.
|
|
|
|
<br><dt><samp><span class="env">--strip-unneeded-symbols=</span><var>filename</var></samp><dd>Apply <samp><span class="option">--strip-unneeded-symbol</span></samp> option to each symbol listed in
|
|
the file <var>filename</var>. <var>filename</var> 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.
|
|
|
|
<br><dt><samp><span class="env">--keep-global-symbols=</span><var>filename</var></samp><dd>Apply <samp><span class="option">--keep-global-symbol</span></samp> option to each symbol listed in the
|
|
file <var>filename</var>. <var>filename</var> 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.
|
|
|
|
<br><dt><samp><span class="env">--localize-symbols=</span><var>filename</var></samp><dd>Apply <samp><span class="option">--localize-symbol</span></samp> option to each symbol listed in the file
|
|
<var>filename</var>. <var>filename</var> 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.
|
|
|
|
<br><dt><samp><span class="env">--globalize-symbols=</span><var>filename</var></samp><dd>Apply <samp><span class="option">--globalize-symbol</span></samp> option to each symbol listed in the file
|
|
<var>filename</var>. <var>filename</var> 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. Note: this option cannot be
|
|
used in conjunction with the <samp><span class="option">-G</span></samp> or <samp><span class="option">--keep-global-symbol</span></samp>
|
|
options.
|
|
|
|
<br><dt><samp><span class="env">--weaken-symbols=</span><var>filename</var></samp><dd>Apply <samp><span class="option">--weaken-symbol</span></samp> option to each symbol listed in the file
|
|
<var>filename</var>. <var>filename</var> 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.
|
|
|
|
<br><dt><samp><span class="env">--alt-machine-code=</span><var>index</var></samp><dd>If the output architecture has alternate machine codes, use the
|
|
<var>index</var>th 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 <var>index</var>
|
|
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.
|
|
|
|
<br><dt><samp><span class="env">--writable-text</span></samp><dd>Mark the output text as writable. This option isn't meaningful for all
|
|
object file formats.
|
|
|
|
<br><dt><samp><span class="env">--readonly-text</span></samp><dd>Make the output text write protected. This option isn't meaningful for all
|
|
object file formats.
|
|
|
|
<br><dt><samp><span class="env">--pure</span></samp><dd>Mark the output file as demand paged. This option isn't meaningful for all
|
|
object file formats.
|
|
|
|
<br><dt><samp><span class="env">--impure</span></samp><dd>Mark the output file as impure. This option isn't meaningful for all
|
|
object file formats.
|
|
|
|
<br><dt><samp><span class="env">--prefix-symbols=</span><var>string</var></samp><dd>Prefix all symbols in the output file with <var>string</var>.
|
|
|
|
<br><dt><samp><span class="env">--prefix-sections=</span><var>string</var></samp><dd>Prefix all section names in the output file with <var>string</var>.
|
|
|
|
<br><dt><samp><span class="env">--prefix-alloc-sections=</span><var>string</var></samp><dd>Prefix all the names of all allocated sections in the output file with
|
|
<var>string</var>.
|
|
|
|
<br><dt><samp><span class="env">--add-gnu-debuglink=</span><var>path-to-file</var></samp><dd>Creates a .gnu_debuglink section which contains a reference to
|
|
<var>path-to-file</var> and adds it to the output file. Note: the file at
|
|
<var>path-to-file</var> 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.
|
|
|
|
<p>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 <samp><span class="option">--add-gnu-debuglink</span></samp>
|
|
option will fail because the installed file does not exist yet.
|
|
Instead put the debug info file in the current directory and use the
|
|
<samp><span class="option">--add-gnu-debuglink</span></samp> option without any directory components,
|
|
like this:
|
|
|
|
<pre class="smallexample"> objcopy --add-gnu-debuglink=foo.debug
|
|
</pre>
|
|
<p>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:
|
|
|
|
<dl>
|
|
<dt><code>* The same directory as the executable.</code>
|
|
<br><dt><code>* A sub-directory of the directory containing the executable</code><dd>called .debug
|
|
|
|
<br><dt><code>* A global debug directory such as /usr/lib/debug.</code><dd></dl>
|
|
|
|
<p>As long as the debug info file has been installed into one of these
|
|
locations before the debugger is run everything should work
|
|
correctly.
|
|
|
|
<br><dt><samp><span class="env">--keep-file-symbols</span></samp><dd>When stripping a file, perhaps with <samp><span class="option">--strip-debug</span></samp> or
|
|
<samp><span class="option">--strip-unneeded</span></samp>, retain any symbols specifying source file names,
|
|
which would otherwise get stripped.
|
|
|
|
<br><dt><samp><span class="env">--only-keep-debug</span></samp><dd>Strip a file, removing contents of any sections that would not be
|
|
stripped by <samp><span class="option">--strip-debug</span></samp> and leaving the debugging sections
|
|
intact. In ELF files, this preserves all note sections in the output.
|
|
|
|
<p>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.
|
|
|
|
<p>The intention is that this option will be used in conjunction with
|
|
<samp><span class="option">--add-gnu-debuglink</span></samp> 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:
|
|
|
|
<ol type=1 start=1>
|
|
<li>Link the executable as normal. Assuming that it is called
|
|
<code>foo</code> then...
|
|
<li>Run <code>objcopy --only-keep-debug foo foo.dbg</code> to
|
|
create a file containing the debugging info.
|
|
<li>Run <code>objcopy --strip-debug foo</code> to create a
|
|
stripped executable.
|
|
<li>Run <code>objcopy --add-gnu-debuglink=foo.dbg foo</code>
|
|
to add a link to the debugging info into the stripped executable.
|
|
</ol>
|
|
|
|
<p>Note—the choice of <code>.dbg</code> as an extension for the debug info
|
|
file is arbitrary. Also the <code>--only-keep-debug</code> step is
|
|
optional. You could instead do this:
|
|
|
|
<ol type=1 start=1>
|
|
<li>Link the executable as normal.
|
|
<li>Copy <code>foo</code> to <code>foo.full</code>
|
|
<li>Run <code>objcopy --strip-debug foo</code>
|
|
<li>Run <code>objcopy --add-gnu-debuglink=foo.full foo</code>
|
|
</ol>
|
|
|
|
<p>i.e., the file pointed to by the <samp><span class="option">--add-gnu-debuglink</span></samp> can be the
|
|
full executable. It does not have to be a file created by the
|
|
<samp><span class="option">--only-keep-debug</span></samp> switch.
|
|
|
|
<p>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.
|
|
|
|
<br><dt><samp><span class="env">--strip-dwo</span></samp><dd>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 <samp><span class="option">-gsplit-dwarf</span></samp> 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 <samp><span class="option">--extract-dwo</span></samp> option to copy the .dwo sections to
|
|
the .dwo file, then the <samp><span class="option">--strip-dwo</span></samp> option to remove
|
|
those sections from the original .o file.
|
|
|
|
<br><dt><samp><span class="env">--extract-dwo</span></samp><dd>Extract the contents of all DWARF .dwo sections. See the
|
|
<samp><span class="option">--strip-dwo</span></samp> option for more information.
|
|
|
|
<br><dt><samp><span class="env">--file-alignment </span><var>num</var></samp><dd>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.]
|
|
|
|
<br><dt><samp><span class="env">--heap </span><var>reserve</var></samp><dt><samp><span class="env">--heap </span><var>reserve</var><span class="env">,</span><var>commit</var></samp><dd>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.]
|
|
|
|
<br><dt><samp><span class="env">--image-base </span><var>value</var></samp><dd>Use <var>value</var> 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.]
|
|
|
|
<br><dt><samp><span class="env">--section-alignment </span><var>num</var></samp><dd>Sets the section alignment field in the PE header. 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.]
|
|
|
|
<br><dt><samp><span class="env">--stack </span><var>reserve</var></samp><dt><samp><span class="env">--stack </span><var>reserve</var><span class="env">,</span><var>commit</var></samp><dd>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.]
|
|
|
|
<br><dt><samp><span class="env">--subsystem </span><var>which</var></samp><dt><samp><span class="env">--subsystem </span><var>which</var><span class="env">:</span><var>major</var></samp><dt><samp><span class="env">--subsystem </span><var>which</var><span class="env">:</span><var>major</var><span class="env">.</span><var>minor</var></samp><dd>Specifies the subsystem under which your program will execute. The
|
|
legal values for <var>which</var> are <code>native</code>, <code>windows</code>,
|
|
<code>console</code>, <code>posix</code>, <code>efi-app</code>, <code>efi-bsd</code>,
|
|
<code>efi-rtd</code>, <code>sal-rtd</code>, and <code>xbox</code>. You may optionally set
|
|
the subsystem version also. Numeric values are also accepted for
|
|
<var>which</var>.
|
|
[This option is specific to PE targets.]
|
|
|
|
<br><dt><samp><span class="env">--extract-symbol</span></samp><dd>Keep the file's section flags and symbols but remove all section data.
|
|
Specifically, the option:
|
|
|
|
<ul>
|
|
<li>removes the contents of all sections;
|
|
<li>sets the size of every section to zero; and
|
|
<li>sets the file's start address to zero.
|
|
</ul>
|
|
|
|
<p>This option is used to build a <samp><span class="file">.sym</span></samp> file for a VxWorks kernel.
|
|
It can also be a useful way of reducing the size of a <samp><span class="option">--just-symbols</span></samp>
|
|
linker input file.
|
|
|
|
<br><dt><samp><span class="env">--compress-debug-sections</span></samp><dd>Compress DWARF debug sections using zlib with SHF_COMPRESSED from the
|
|
ELF ABI. Note - if compression would actually make a section
|
|
<em>larger</em>, then it is not compressed.
|
|
|
|
<br><dt><samp><span class="env">--compress-debug-sections=none</span></samp><dt><samp><span class="env">--compress-debug-sections=zlib</span></samp><dt><samp><span class="env">--compress-debug-sections=zlib-gnu</span></samp><dt><samp><span class="env">--compress-debug-sections=zlib-gabi</span></samp><dd>For ELF files, these options control how DWARF debug sections are
|
|
compressed. <samp><span class="option">--compress-debug-sections=none</span></samp> is equivalent
|
|
to <samp><span class="option">--decompress-debug-sections</span></samp>.
|
|
<samp><span class="option">--compress-debug-sections=zlib</span></samp> and
|
|
<samp><span class="option">--compress-debug-sections=zlib-gabi</span></samp> are equivalent to
|
|
<samp><span class="option">--compress-debug-sections</span></samp>.
|
|
<samp><span class="option">--compress-debug-sections=zlib-gnu</span></samp> compresses DWARF debug
|
|
sections using zlib. The debug sections are renamed to begin with
|
|
‘<samp><span class="samp">.zdebug</span></samp>’ instead of ‘<samp><span class="samp">.debug</span></samp>’. Note - if compression would
|
|
actually make a section <em>larger</em>, then it is not compressed nor
|
|
renamed.
|
|
|
|
<br><dt><samp><span class="env">--decompress-debug-sections</span></samp><dd>Decompress DWARF debug sections using zlib. The original section
|
|
names of the compressed sections are restored.
|
|
|
|
<br><dt><samp><span class="env">--elf-stt-common=yes</span></samp><dt><samp><span class="env">--elf-stt-common=no</span></samp><dd>For ELF files, these options control whether common symbols should be
|
|
converted to the <code>STT_COMMON</code> or <code>STT_OBJECT</code> type.
|
|
<samp><span class="option">--elf-stt-common=yes</span></samp> converts common symbol type to
|
|
<code>STT_COMMON</code>. <samp><span class="option">--elf-stt-common=no</span></samp> converts common symbol
|
|
type to <code>STT_OBJECT</code>.
|
|
|
|
<br><dt><samp><span class="env">--merge-notes</span></samp><dt><samp><span class="env">--no-merge-notes</span></samp><dd>For ELF files, attempt (or do not attempt) to reduce the size of any
|
|
SHT_NOTE type sections by removing duplicate notes.
|
|
|
|
<br><dt><samp><span class="env">-V</span></samp><dt><samp><span class="env">--version</span></samp><dd>Show the version number of <samp><span class="command">objcopy</span></samp>.
|
|
|
|
<br><dt><samp><span class="env">--verilog-data-width=</span><var>bytes</var></samp><dd>For Verilog output, this options controls the number of bytes
|
|
converted for each output data element. The input target controls the
|
|
endianness of the conversion.
|
|
|
|
<br><dt><samp><span class="env">-v</span></samp><dt><samp><span class="env">--verbose</span></samp><dd>Verbose output: list all object files modified. In the case of
|
|
archives, ‘<samp><span class="samp">objcopy -V</span></samp>’ lists all members of the archive.
|
|
|
|
<br><dt><samp><span class="env">--help</span></samp><dd>Show a summary of the options to <samp><span class="command">objcopy</span></samp>.
|
|
|
|
<br><dt><samp><span class="env">--info</span></samp><dd>Display a list showing all architectures and object formats available.
|
|
</dl>
|
|
|
|
<!-- man end -->
|
|
</body></html>
|
|
|