GNU Binutils

The GNU Binutils are a collection of binary tools. The main ones are:

ld - the GNU linker.
as - the GNU assembler.
gold - a new, faster, ELF only linker.

But they also include:

addr2line - Converts addresses into filenames and line numbers.
ar - A utility for creating, modifying and extracting from archives.
c++filt - Filter to demangle encoded C++ symbols.
dlltool - Creates files for building and using DLLs.
elfedit - Allows alteration of ELF format files.
gprof - Displays profiling information.
gprofng - Collects and displays application performance data.
nlmconv - Converts object code into an NLM.
nm - Lists symbols from object files.
objcopy - Copies and translates object files.
objdump - Displays information from object files.
ranlib - Generates an index to the contents of an archive.
readelf - Displays information from any ELF format object file.
size - Lists the section sizes of an object or archive file.
strings - Lists printable strings from files.
strip - Discards symbols.
windmc - A Windows compatible message compiler.
windres - A compiler for Windows resource files.

As well as some libraries:

libbfd - A library for manipulating binary files in a variety of differen formats.
libctf - A library for manipulating the CTF debug format.
libopcodes - A library for assembling and disassembling a variety of different assembler languages.
libsframe - A library for manipulating the SFRAME debug format.

Most of these programs use BFD, the Binary File Descriptor library, to do low-level manipulation. Many of them also use the opcodes library to assemble and disassemble machine instructions.

The binutils have been ported to most major Unix variants as well as Wintel systems, and their main reason for existence is to give the GNU system (and GNU/Linux) the facility to compile and link programs.

Obtaining binutils

The latest release of GNU binutils is 2.40. The various NEWS files (binutils, gas and ld) have details of what has changed in this release.

See the SOFTWARE page for information on obtaining releases of GNU binutils and other GNU software. The current release can be downloaded from https://ftp.gnu.org/gnu/binutils or https://sourceware.org/pub/binutils/releases/

If you plan to do active work on GNU binutils, you can access the development source tree by anonymous git:

  git clone https://sourceware.org/git/binutils-gdb.git

Alternatively, you can use the gitweb interface, or the source snapshots, available as compressed tar files from https://sourceware.org/pub/binutils/snapshots/.

Bug reports

There is a bug-tracking system at http://sourceware.org/bugzilla/.

Mailing lists

There are three binutils mailing lists:

bug-binutils@gnu.org (archives): For reporting bugs.
binutils@sourceware.org (archives): For discussing binutils issues.
binutils-cvs (archives): A read-only mailing list containing the notes from checkins to the binutils git repository. (This list has an odd name for historical reasons.)

To subscribe to the binutils@sourceware.org mailing list, see the binutils mailing list page.

To subscribe to the bug-binutils@gnu.org mailing list, see the bug-binutils info page.

You may wish to browse the old mail archives of the gas2 and bfd mailing lists. These were the discussion lists for binutils until May 1999. Please do not send mail to them any longer.

Documentation

The documentation for binutils 2.40 is available.

A guide to porting the binutils to a new target has been contributed.

A wiki for the GNU Binutils contains more information about the project and the various tools that it contains.

Return to GNU's home page.

Please send FSF & GNU inquiries & questions to gnu@gnu.org. There are also other ways to contact the FSF.

Please send comments on these web pages to binutils@sourceware.org, send other questions to gnu@gnu.org.

Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved.

Updated: Last modified: Sat Jan 15 15:47:03 UCT 2023