• 2015-11-20: Released 1.22.0. Get it as bz2 (PGP sig) or xz (PGP sig) Feature-release
  • 2015-05-25: Released 1.21.0. Get it as bz2 (PGP sig) or xz (PGP sig) Feature-release
  • 2014-12-05: Source control is moving to Github! This will make contributing to crosstool-NG simpler, and also now we can track issues! Read this email for more info!
  • 2014-12-02: Bryan Hundven has taken over as maintainer. Yann E. MORIN continues as a developer and stays on as an admin for site and release process.
  • 2014-09-09: Released 1.20.0. Get it as bz2 (PGP sig) or xz (PGP sig) Feature-release
  • 2014-09-05: The server now has a new IP address, and should now be reachable again; just let the DNS caches expire, so the new address propagates. The root cause is as of yet unknown, but hopefully, this will not happen anymore. Thanks to the OSUOSL guys for their help in solving this issue! :-)
  • 2014-08-05: It seems the crosstool-NG server is unreachable for some parts of the world. The issue is being investigated (update 2014-08-11: the configuration of the server is OK; there is a routing issue somewhere).
  • 2014-06-27: We now have a git tree! The Mercurial trees are now read-only, development will be done only on the git tree.
  • 2013-10-02: Released 1.19.0 ( md5 - changelog - fixes ) Feature-release
  • 2013-03-20: The mailing list is back to operational conditions! Thanks, and well done,! :-)
  • 2013-03-19:, which is hosting the crossgcc mailing list, is undergoing infrastructure overhaul, so the mailing list, and its archives, will be unreachable for a good part of the week. Sorry for the inconvenience. Stay tuned for more information.
  • 2013-01-31: Released 1.18.0 ( md5 - changelog - fixes ) Feature-release
  • 2012-11-11: Released 1.17.0 ( md5 - changelog - fixes ) Feature-release
  • 2012-10-31: The next release was due tonight. It's gonna be late, by at least a few days… :-(
  • 2012-08-04: Released 1.16.0 ( md5 - changelog - fixes ) Feature-release
  • 2012-08-01: The next major release was due yesterday, but it is late. A few last-minute fixes to test, and it should be ready soon (expect before the week-end).
  • 2012-07-17: Released 1.15.3 ( md5 - changelog - fixes ) (bug-fix)
  • 2012-05-08: Released 1.15.2 ( md5 - changelog - fixes ) (bug-fix)
  • 2012-05-08: Released 1.15.1 ( md5 - changelog - fixes ) (bug-fix) This release is broken! Do not use it!
  • 2012-04-30: Released 1.15.0 ( md5 - changelog - fixes ) Feature-release
  • 2012-04-30: The canadian patch-queue has been upstreamed.



crosstool-NG aims at building toolchains. Toolchains are an essential component in a software development project. It will compile, assemble and link the code that is being developed. Some pieces of the toolchain will eventually end up in the resulting binary/ies: static libraries are but an example.

So, a toolchain is a very sensitive piece of software, as any bug in one of the components, or a poorly configured component, can lead to execution problems, ranging from poor performance, to applications ending unexpectedly, to mis-behaving software (which more than often is hard to detect), to hardware damage, or even to human risks (which is more than regrettable).

Toolchains are made of different pieces of software, each being quite complex and requiring specially crafted options to build and work seamlessly. This is usually not that easy, even in the not-so-trivial case of native toolchains. The work reaches a higher degree of complexity when it comes to cross-compilation, where it can become quite a nightmare…

Some cross-toolchains exist on the internet, and can be used for general development, but they have a number of limitations:

  • they can be general purpose, in that they are configured for the majority: no optimisation for your specific target,
  • they can be prepared for a specific target and thus are not easy to use, nor optimised for, or even supporting your target,
  • they often are using aging components (compiler, C library, etc…) not supporting special features of your shiny new processor;

On the other side, these toolchains offer some advantages:

  • they are ready to use and quite easy to install and setup,
  • they are proven if used by a wide community.

But once you want to get all the juice out of your specific hardware, you will want to build your own toolchain. This is where crosstool-NG comes into play.

There are also a number of tools that build toolchains for specific needs, which are not really scalable. Examples are:

  • buildroot whose main purpose is to build complete root file systems, hence the name. But once you have your toolchain with buildroot, part of it is installed in the root-to-be, so if you want to build a whole new root, you either have to save the existing one as a template and restore it later, or restart again from scratch. This is not convenient,
  • ptxdist, whose purpose is very similar to buildroot,
  • other projects (openembedded for example), which is again used to build complete root file systems.

crosstool-NG is really targetted at building toolchains, and only toolchains. It is then up to you to use it the way you want.

With crosstool-NG, you can learn precisely how each component is configured and built, so you can finely tweak the build steps should you need it.

crosstool-NG can build from generic, general purpose toolchains, to very specific and dedicated toolchains. Simply fill in specific values in the adequate options.

Of course, it doesn't prevent you from doing your home work first. You have to know with some degree of exactitude what your target is (archictecture, processor variant), what it will be used for (embedded, desktop, realtime), what degree of confidence you have with each component (stability, maintainability), and so on…

NOTE: crosstool-NG is a rewrite of the original crosstool by Dan Kegel by Yann E. MORIN. Big thanks Dan for putting his original work on-line! And a HUGE thanks to Yann for this terrific tool!


It's quite difficult to list all possible features available in crosstool-NG. Here is a list of those I find important:

  • kernel-like menuconfig configuration interface
    • widespread, well-known interface
    • easy, yet powerful configuration
  • growing number of supported architectures
  • support for alternative components in the toolchain
    • uClibc-, glibc-, newlib-, musl-libc-based toolchain supported right now!
    • others easy to implement
  • different target OS supported
    • Linux
    • bare metal
  • patch repository for those versions needing patching
    • patches for many versions of the toolchain components
    • support for custom (understand local) patch repository
  • different threading models
    • NPTL
    • linuxthreads
  • support for both soft- and hard-float toolchains
  • support for multlib toolchains (experimental for now)
  • debug facilities
    • native and cross gdb, gdbserver
    • debugging libraries: dmalloc, duma
    • debugging tools: ltrace, strace
    • restart a build at any step
  • sample configurations repository usable as starting point for your own toolchain

Download and usage

You can:

Using a released version

If you decide to use a released version (replace VERSION with the actual version you choose; the latest version is listed at the top of this page):


Starting with 1.21.0, releases are signed with Bryan Hundven's pgp key

The fingerprint is:

561E D9B6 2095 88ED 23C6 8329 CAD7 C8FC 35B8 71D1

The public key is found on:


To validate the release tarball run you need to import the key from the keyserver and download the signature of the tarball:

gpg --recv-keys 35B871D1

Now, with the tarball and signature in the same directory, you can verify the tarball:

gpg --verify crosstool-ng-VERSION.tar.bz2.sig

Now you can unpack and install crosstool-NG:

tar xjf crosstool-ng-VERSION.tar.bz2
cd crosstool-ng-VERSION
./configure --prefix=/some/place
make install
export PATH="${PATH}:/some/place/bin"

Then, you are ready to use crosstool-NG.

  • create a place to work in, then list the existing samples (pre-configured toolchains that are known to build and work) to see if one can fit your actual needs. Sample names are 4-part tuples, such as arm-unknown-linux-gnueabi. In the following, we'll use that as a sample name; adapt to your needs:
mkdir /a/directory/to/build/your/toolchain
cd /a/directory/to/build/your/toolchain
ct-ng help
ct-ng list-samples
ct-ng show-arm-unknown-linux-gnueabi
  • once you know what sample to use, configure ct-ng to use it:
ct-ng arm-unknown-linux-gnueabi
  • samples are configured to install in "${HOME}/x-tools/arm-unknown-linux-gnueabi" by default. This should be OK for a first time user, so you can now build your toolchain:
ct-ng build
  • finally, you can set access to your toolchain, and call your new cross-compiler with :
export PATH="${PATH}:${HOME}/x-tools/arm-unknown-linux-gnueabi/bin"

Of course, replace arm-unknown-linux-gnueabi with the actual sample name you choose! ;-)

If no sample really fits your needs:

  1. choose the one closest to what you want (see above), and start building it (see above, too)
    1. this ensures sure it is working for your machine, before trying to do more advanced tests
  2. fine-tune the configuration, and re-run the build, with:
ct-ng menuconfig
ct-ng build

Then, if all goes well, your toolchain will be available and you can set access to it as shown above.

See contacts, below for how to ask for further help.

Note 1: If you elect to build a uClibc-based toolchain, you will have to prepare a config file for uClibc with ⇐ crosstool-NG-1.21.0. In >= crosstool-NG-1.22.0 you only need to prepare a config file for uClibc(or uClibc-ng) if you really need a custom config for uClibc.

Note 2: If you call ct-ng --help you will get help for make(2). This is because ct-ng is in fact a make(2) script. There is no clean workaround for this.

Using the latest development stuff

If you want to use the latest development stuff:

git clone git://


git clone
cd crosstool-ng
./configure --enable-local
./ct-ng help
./ct-ng menuconfig
./ct-ng build

Repository layout

URL Purpose All available development repositories Mirror of the development repository Main development repository

To clone the main repository:

git clone

You can also download from our mirror at

git clone git://

Alternatively, if you are sitting behind a restrictive proxy that does not let the git protocol through, you can clone with:

git clone

Old repositories

These are the old Mercurial repositories. They are now read-only:

Pull Requests and Issues

You can find open Pull Requests on GitHub here and you can find open issues here.


We previously used patchwork for development, but it is no longer used. I'd like to see patches that are still applicable turned into Pull Requests on GitHub.

You can find the list of pending patches available on patchwork.


Here are a few hints on how to ask for help:

Problem Where/whom to ask for help
– A component (gcc, binutils, C library…) does not build.
– Generated files do not work.
crosstool-NG breaks.
– You have improvements and/or fixes for crosstool-NG or this WiKi page.
Send a mail To: the crossgcc mailing list
Alternatively, there is an IRC channel where some of us wander from time to time…
Note: prefer posting on the mailing list before going to the IRC channel. Using the mailing list will allow you to ask more detailed questions than the IRC channel usually allows for.
– You find crosstool-NG usefull.
– You succeeded in your project partly thanks to crosstool-NG.
Drop me a little explanation (without breaking your company's rules, if any), and I'll post your feedback on this page. :-)
– You need personal assistance.
– You demand that I add a feature you need.
– You demand that I answer your mails instantly.
Well, I program crosstool-NG on my free time, on a voluntary basis, without being paid (so far), and mostly because I needed it. It is based on code freely contributed by many people over many years. How can you demand anything? If at least you offered payement…
– You are a nice girl from Russia (or wherever), and you have pictures of your big breast to show me. Send mail To: /dev/null :-P

Quotation lamely stolen from original crosstool :

For questions, comments or improvements see the crossgcc mailing list, but do your homework first.
As Bill Gatliff says, "THINK!"

IRC who's who, and usual time of presence

The IRC support channel is #crosstool-ng on
The IRC channel is logged (today's log).

Usual time-slot of presence (UTC)
Nick Person Timezone Week Week-end
y_morin Yann E. MORIN UTC+0200
with DST
~16:30 - 23:00 ~09:00 - ~16:30 (random presence)
~16:30 - 23:00
bhundven Bryan Hundven UTC-0800
with DST
~09:00 - 21:00 ~09:00 - ~21:00

Note: If you are a regular on the channel, just tell me if you wish to appear in the table above.

Refering to crosstool-NG

The long name of the project is crosstool-NG:

  • no leading uppercase (except as first word in a sentence)
  • crosstool and NG separated with a hyphen (dash)
  • NG in uppercase

Crosstool-NG can also be referred to by its short name CT-NG:

  • all in uppercase
  • CT and NG separated with a hyphen (dash)

The long name is preferred over the short name, except in mail subjects, where the short name is a better fit.

When referring to a specific version of crosstool-NG, append the version number either as:

  • crosstool-NG X.Y.Z
    • the long name, a space, and the version string
  • crosstool-ng-X.Y.Z
    • the long name in lowercase, a hyphen (dash), and the version string
    • this is used to name the release tarballs

The frontend to crosstool-NG is the command ct-ng:

  • all in lowercase
  • ct and ng separated by a hyphen (dash)


Here is the list of target architectures crosstool-NG currently supports:

Endianness Bitness
Architecture Big Little 32 64
Alpha ? Y Y ?
AVR32 (EXP) Y N.A. Y N.A.
microblaze Y Y Y N/A
OpenRISC/or32(+) ? Y N.A.
PowerPC Y ? Y Y
s390 Y N.A. Y Y
SuperH (EXP) ? Y ?
x86 N.A. Y Y Y

EXP: Basic support is there, but it is considered EXPERIMENTAL.
(+) OpenRISC is present as contributed code only (see ./configure --with-contrib=list).

Here are some of the toolchains that were successfully built with crosstool-NG. Of course, there are many other working combinations, but I focus on making the latest versions working.

20151117.1311 -0800
Target Host Status Kernel headers
C compiler
C library
Floating point
Languages Initially
reported by
alphaev56-unknown-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl C, C++ Ioannis E. VENETIS 2015-11-14
alphaev67-unknown-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl C, C++ Ioannis E. Venetis 2015-11-14
arm-bare_newlib_cortex_m3_nommu-eabi bare-metal 2.25.1 gcc 5.2.0 newlib 2.2.0 none soft C, C++ Yann E. MORIN 2015-11-14
arm-cortex_a15-linux-gnueabi linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl hard C, C++ dsreed on freenode/#crosstool-ng 2015-11-14
arm-cortexa5-linux-uclibcgnueabihf X linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl hard C, C++ Alexandre Belloni 2015-11-14
arm-cortex_a8-linux-gnueabi linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl soft C, C++ Yann E. MORIN 2015-11-14
arm-cortexa9_neon-linux-gnueabihf X linux 4.3 2.22 gcc 5.2.0 glibc 2.22 nptl hard C, C++ Benoît Thébaudeau 2015-11-14
armeb-unknown-eabi bare-metal 2.25.1 gcc 5.2.0 none none soft C YEM 2014-09-02
armeb-unknown-linux-gnueabi linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl soft C, C++ YEM 2015-11-14
armeb-unknown-linux-uclibcgnueabi linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl soft C, C++ YEM 2015-11-14
arm-unknown-eabi bare-metal 2.25.1 gcc 5.2.0 newlib 2.2.0 none soft C, C++ YEM 2014-09-05
arm-unknown-linux-gnueabi linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl soft C, C++ Alexander BIGGA 2015-11-14
arm-unknown-linux-musleabi X linux 4.3 2.25.1 gcc 5.2.0 musl 1.1.12 musl auto C, C++ Bryan Hundven 2015-10-21
arm-unknown-linux-uclibcgnueabi linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl soft C, C++ Thomas Petazzoni 2015-11-14
arm-unknown-linux-uclibcgnueabihf X linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl hard C, C++ Yann E. MORIN 2015-11-14
armv6-rpi-linux-gnueabi linux 3.12.50 2.25.1 gcc 5.2.0 glibc 2.22 nptl auto C, C++ Yann E. MORIN 2015-11-14
armv7-rpi2-linux-gnueabihf linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl hard C, C++ Frederick Zhang <> 2015-11-14
avr bare-metal 2.25.1 gcc 4.9.3 avr-libc 1.8.1 none C, C++ Erico Nunes 2015-10-31
i586-geode-linux-uclibc linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl C, C++ YEM 2015-11-12
i686-none-linux-gnu i586-mingw32msvc B linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl C, C++ (unknown) 2015-11-14
i686-nptl-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl C, C++ YEM 2015-11-14
i686-w64-mingw32 windows 2.25.1 gcc 5.2.0 mingw 4.0.4 win32 C, C++ Yann Diorcet diorcet [dot] yann [at] gmail [dot] com 2015-11-14
m68k-unknown-elf bare-metal 2.25.1 gcc 5.2.0 none none C Remy Bohmer 2014-09-02
m68k-unknown-uclinux-uclibc linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 linuxthreads C Esben Haabendal 2015-11-12
mips64el-n32-linux-uclibc linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl soft C, C++ Yann E. MORIN 2015-11-14
mips64el-n64-linux-uclibc linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl soft C, C++ Yann E. MORIN 2015-11-14
mips-ar2315-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl soft C, C++ Giammarco Zacheo 2015-11-14
mipsel-sde-elf bare-metal 2.25.1 gcc 5.2.0 none none soft C Kevin Cernekee 2014-09-06
mipsel-unknown-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl soft C, C++ Alexander BIGGA 2015-11-14
mips-malta-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl auto C, C++ Antony Pavlov 2015-11-14
mips-unknown-elf bare-metal 2.25.1 gcc 5.2.0 none none soft C YEM 2014-09-06
mips-unknown-linux-uclibc linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl soft C, C++ YEM 2015-11-14
nios2-spico-elf i686-w64-mingw32 X bare-metal 2.25 gcc 5.2.0 newlib 2.2.0 none C, C++ Daniel Zimmermann <> 2015-11-13
powerpc-405-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl soft C, C++ Julien DUSSER 2015-11-14
powerpc64-unknown-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl auto C, C++ Yann E. MORIN 2015-11-14
powerpc-860-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl soft C, C++ Nye Liu 2015-11-14
powerpc-e300c3-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl auto C, C++ Gustavo Zacarias <> 2015-11-14
powerpc-e500v2-linux-gnuspe linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl soft C, C++ Anthony Foiani <> 2015-10-15
powerpc-unknown-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl auto C, C++ Thomas JOURDAN 2015-11-14
powerpc-unknown-linux-uclibc B linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl soft C, C++, Fortran Daniel DITTMANN 2015-11-14
powerpc-unknown_nofpu-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl soft C, C++ Thomas JOURDAN 2015-11-14
s390-ibm-linux-gnu X linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl C, C++ Harold Grovesteen 2015-11-14
s390x-ibm-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl C, C++ Harold Grovesteen 2015-11-14
sh4-unknown-linux-gnu linux 4.3 2.25.1 gcc 4.9.3 glibc 2.22 nptl C, C++ YEM 2015-10-15
sparc-unknown-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl auto C Yann E. MORIN 2015-11-14
x86_64-pc-linux-gnu x86_64-w64-mingw32 X linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl C, C++ Ray Donnelly 2015-11-14
x86_64-unknown-linux-gnu linux 4.3 2.25.1 gcc 5.2.0 glibc 2.22 nptl C, C++ Thomas JOURDAN 2015-11-14
x86_64-unknown-linux-uclibc linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl C, C++ YEM 2015-11-14
x86_64-w64-mingw32 windows 2.25.1 gcc 5.2.0 mingw 4.0.4 win32 C, C++ Yann Diorcet diorcet [dot] yann [at] gmail [dot] com 2015-11-14
xtensa-unknown-linux-uclibc linux 4.3 2.25.1 gcc 5.2.0 uClibc-ng 1.0.9 nptl C, C++ Max Filippov 2015-11-13
Total: 50 samples X: sample uses features marked as being EXPERIMENTAL.
B: sample is currently BROKEN.
20110424.141718 · Yann E. MORIN

Note: The above table reflects the state of the git repository at the time it (the table) was built. And it is periodically refreshed, every hour (not for now, hand-refreshed, pending server update).
Note 2: If you have other working combinations, please send in the config file(s), they'll get added to the samples repository in crosstool-NG, so that every one can benefit from it. As a bonus, the above table will be automatically updated with your name! ;-)
Note 3: This table is directly accessible here.

crosstool-NG needs your help!

As I said above, I can't test on all platforms. Anyone volunteering to test on alternate platforms I haven't access to (or even ones I have access to) is welcome to report success/failure on those platforms. Thank you!


This is an informal, somewhat-unordered TODO list:

  • add a test suite for the generated toolchains
    • test-build is here
    • need to test generated toolchains (needs real HW or emulator)
  • add other hosts, targets or systems support
    • other hardware architectures
    • Windows
      • Cygwin
        • works as host
        • having target support is a TODO (would be nice)
    • MacOS-X
      • seems functional as host (some reports suggest it is, at least)
      • completely unknown to me as whether it could be added as a target
    • *BSD systems
      • absolutely unknown to me
  • Multilib support
  • create a collection of standard targets [on-going in sub-directory samples/]

Misc mumble

Canadian build

That one is tricky as well, but we should be able to overcome most of the problems lying in front of us…

NOTE: There is support for building canadian-crosses right now. It's not perfect, some cleanups have to be done, but it works quite OK.

Let's take the worst case, where build != host != target. So for a compiler built on build, running on host, generating code for target:

We need a compiler that…
runs on… and generates
code for…
to build… that runs
and generates
code for…
1 build build X-binutils and X-compiler build host
1 build build X-binutils and X-compiler build target
2 build host C library (and helpers) host N.A.
3 build target C library (and helpers) target N.A.
to build a toolchain that…
runs on… generates
code for…
to build… that runs
and generates
code for…
4 host target our very-own software :-D target :-D N.A.

As you see, generating a full canadian cross-compiler is no easy task. We will assume that the native compiler on the first two lines (1) is available on your system.

Then, the two cross-compilers for buildhost (2) and buildtarget (3) are assumed to be present. They most probably will be build using crosstool-NG! :-P

Finally, we would be able to buildthe cross-compiler we're interested in (4).

Note that it would be very complex to provide options for those compilers in a single config menu (it would almost triple the menu items!). Thus, we'd need to configure them as separate compilers.

Once the canadian build proper works, we could have a wrapper script take the three configurations, and build the three toolchains in turn. But that would be only for convenience, as we'd still need to provide correct configuration for every compilers.

So here is a list of things to do, in order:

  1. build a cross-compiler for host to run on build
  2. build a cross-compiler for target to run on build
  3. build a canadian cross-compiler for target to run on host


Cygwin as host

Cygwin should be a functional host by now. There still are quirks to work around (mostly due to how Cygwin wraps the Win32 API to provide POSIX semantics), but the core of crosstool-NG is playing nicely now.

One major drawback of running under Cygwin is the performance impact, notably when dealing with files, but not only:

  • open(2), read(2), opendir(2) and readdir(2) are really slow
  • the directory under which the build is done must be mounted with the -o managed option, or the build will fail, due to issues with case sensitivity
  • there seem to be a limitation in file name size, that appears to be shorter than under other real POSIX systems, at least when compared to Linux
  • fork(2) is slow as hell

Note: with the recently released Cygwin 1.7 series, mount no longer supports -o managed. Look at the Cygwin FAQ.

Cygwin as target

This will need newlib being supported first: Cygwin is built around newlib, not glibc nor uClibc, so crosstool-NG will have to be able to build newlib-based toolchains prior to be able to target cygwin.

Other systems


MacOS X as a build system seems to have issues with the configurator: you must pass KBUILD_NO_NLS=1 on the make command line, as to not configure the internationalisation. Thanks go to Allan Clark for the patch.

Also, some of the tools there are not up-to-date with the one required by crosstool-NG:

  • the bash version there (2.05b) doesn't support set -E. Only starting with 3.0 does bash support set -E. I have no fix yet.
  • the sed version does not understand some flags (-r, for extended regular expressions, is not accepted). So the install fails.
  • the date command does accept nanoseconds format %N.
  • seems also that bash is limited to doing 32-bit maths, when I need 64-bit maths (cause of nanoseconds).

Exotic languages


GCC Java support is experimental, and as per, it also seems to not get updated much. I'm thinking GCC Java support is not very well supported upstream. As such, not very well supported here either.


Fortran is supported as of release 1.1.0. A Fortran cross-compiler was built for some architectures, but was not tested due to my ignorance of this language. Any taker?


No comment so far.


No comment so far.


No comment so far.


Hahaha! You must be kidding!

Third parties

There are patches floating around that add other frontends to gcc. If anyone reading this page has a need for one of those language, and succeeds in building a toolchain with crosstool-NG, I'd appreciate being sent a patch! :-)


The Pascal frontend to gcc (GPC) is maintained there. Unfortunately, it hasn't changed since March 2005, when it was ported to gcc-3.4.4, and there has been no other release of GPC since then.


Mercury is a declarative logic/functional language developped at the University of Melbourne (or so I think). Latest official release is 0.13.1, dated 20061201, available for both gcc-3.4.x and gcc4.1.x. However, there are ROTD (Release Of The Day) every day since then, available againt gcc-3.4.x only. The developpers mailing list seems quite active.


GHDL is a complete VHDL simulator, using the GCC technology, maintained there. The latest release for GHDL is quite recent (April 2007), and is available for gcc-4.1.2 (not for more recent versions), but the SVN repository seems live. GHDL requires a native GNAT ADA compiler to be built.

Update!! Since I wrote that page, the GHDL project has made some progress, and the latest release is dated 20100111, and is based on gcc-4.3.4


The COBOL frontend, maintained there, is still quite young (started October 2007), but has had a full-time developper for the first six months of its life. The posts to the developpers ML are sparse, but they aim at a first basic subset by June 2008.


As stated on their site, "the intention of GNU Modula-2 is to provide a production modula-2 front end to GCC". The frontend interfaces with gcc-4.1.2 only.


Here are some snapshots of crosstool-NG in action:

And here is a log of a successfull run:

[INFO ]  Performing some trivial sanity checks
[INFO ]  Build started 20110808.233556
[INFO ]  Building environment variables
[EXTRA]  Preparing working directories
[EXTRA]  Installing user-supplied crosstool-NG configuration
[EXTRA]  =================================================================
[EXTRA]  Dumping internal crosstool-NG configuration
[EXTRA]    Building a toolchain for:
[EXTRA]      build  = x86_64-unknown-linux-gnu
[EXTRA]      host   = x86_64-unknown-linux-gnu
[EXTRA]      target = armeb-unknown-linux-uclibcgnueabi
[EXTRA]  Dumping internal crosstool-NG configuration: done in 0.11s (at 00:02)
[INFO ]  =================================================================
[INFO ]  Retrieving needed toolchain components' tarballs
[EXTRA]    Retrieving 'linux-3.0'
[EXTRA]    Retrieving 'gmp-5.0.1'
[EXTRA]    Retrieving 'mpfr-3.0.1'
[EXTRA]    Retrieving 'ppl-0.11.2'
[EXTRA]    Retrieving 'cloog-ppl-0.15.11'
[EXTRA]    Retrieving 'mpc-0.9'
[EXTRA]    Retrieving 'libelf-0.8.13'
[EXTRA]    Retrieving 'binutils-2.21'
[EXTRA]    Retrieving 'gcc-linaro-4.6-2011.07'
[EXTRA]    Retrieving 'uClibc-'
[EXTRA]    Retrieving 'dmalloc-5.5.2'
[EXTRA]    Retrieving 'duma_2_5_15'
[EXTRA]    Retrieving 'gdb-7.1'
[EXTRA]    Retrieving 'ncurses-5.7'
[EXTRA]    Retrieving 'expat-2.0.1'
[EXTRA]    Retrieving 'ltrace_0.5.3.orig'
[EXTRA]    Retrieving 'strace-4.5.19'
[INFO ]  Retrieving needed toolchain components' tarballs: done in 557.99s (at 09:20)
[INFO ]  =================================================================
[INFO ]  Extracting and patching toolchain components
[EXTRA]    Extracting 'linux-3.0'
[EXTRA]    Patching 'linux-3.0'
[EXTRA]    Extracting 'gmp-5.0.1'                                                                                             
[EXTRA]    Patching 'gmp-5.0.1'                                                                                               
[EXTRA]    Extracting 'mpfr-3.0.1'                                                                                            
[EXTRA]    Patching 'mpfr-3.0.1'                                                                                              
[EXTRA]    Extracting 'ppl-0.11.2'                                                                                            
[EXTRA]    Patching 'ppl-0.11.2'                                                                                              
[EXTRA]    Extracting 'cloog-ppl-0.15.11'
[EXTRA]    Patching 'cloog-ppl-0.15.11'
[EXTRA]    Extracting 'mpc-0.9'
[EXTRA]    Patching 'mpc-0.9'
[EXTRA]    Extracting 'libelf-0.8.13'
[EXTRA]    Patching 'libelf-0.8.13'
[EXTRA]    Extracting 'binutils-2.21'
[EXTRA]    Patching 'binutils-2.21'
[EXTRA]    Extracting 'gcc-linaro-4.6-2011.07'
[EXTRA]    Patching 'gcc-linaro-4.6-2011.07'
[EXTRA]    Extracting 'uClibc-'
[EXTRA]    Patching 'uClibc-'
[EXTRA]    Extracting 'dmalloc-5.5.2'
[EXTRA]    Patching 'dmalloc-5.5.2'
[EXTRA]    Extracting 'duma_2_5_15'
[EXTRA]    Patching 'duma-2_5_15'
[EXTRA]    Extracting 'gdb-7.1'
[EXTRA]    Patching 'gdb-7.1'
[EXTRA]    Extracting 'ncurses-5.7'
[EXTRA]    Patching 'ncurses-5.7'
[EXTRA]    Extracting 'expat-2.0.1'
[EXTRA]    Patching 'expat-2.0.1'
[EXTRA]    Extracting 'ltrace-0.5.3'
[EXTRA]    Patching 'ltrace-0.5.3'
[EXTRA]    Extracting 'strace-4.5.19'
[EXTRA]    Patching 'strace-4.5.19'
[INFO ]  Extracting and patching toolchain components: done in 50.04s (at 10:10)
[INFO ]  =================================================================
[INFO ]  Checking C library configuration
[EXTRA]    Munging uClibc configuration
[INFO ]  Checking C library configuration: done in 1.17s (at 10:11)
[INFO ]  =================================================================
[INFO ]  Installing GMP
[EXTRA]    Configuring GMP
[EXTRA]    Building GMP
[EXTRA]    Installing GMP
[INFO ]  Installing GMP: done in 29.16s (at 10:40)
[INFO ]  =================================================================
[INFO ]  Installing MPFR
[EXTRA]    Configuring MPFR
[EXTRA]    Building MPFR
[EXTRA]    Installing MPFR
[INFO ]  Installing MPFR: done in 11.41s (at 10:51)
[INFO ]  =================================================================
[INFO ]  Installing PPL
[EXTRA]    Configuring PPL
[EXTRA]    Building PPL
[EXTRA]    Installing PPL
[INFO ]  Installing PPL: done in 90.91s (at 12:22)
[INFO ]  =================================================================
[INFO ]  Installing CLooG/ppl
[EXTRA]    Configuring CLooG/ppl
[EXTRA]    Building CLooG/ppl
[EXTRA]    Installing CLooG/ppl
[INFO ]  Installing CLooG/ppl: done in 6.28s (at 12:29)
[INFO ]  =================================================================
[INFO ]  Installing MPC
[EXTRA]    Configuring MPC
[EXTRA]    Building MPC
[EXTRA]    Installing MPC
[INFO ]  Installing MPC: done in 6.48s (at 12:35)
[INFO ]  =================================================================
[INFO ]  Installing binutils
[EXTRA]    Configuring binutils
[EXTRA]    Building binutils
[EXTRA]    Installing binutils
[INFO ]  Installing binutils: done in 29.90s (at 13:05)
[INFO ]  =================================================================
[INFO ]  Installing kernel headers
[EXTRA]    Installing kernel headers
[EXTRA]    Checking installed headers
[INFO ]  Installing kernel headers: done in 8.94s (at 13:14)
[INFO ]  =================================================================
[INFO ]  Installing C library headers
[EXTRA]    Copying sources to build dir
[EXTRA]    Applying configuration
[EXTRA]    Building headers
[EXTRA]    Installing headers
[INFO ]  Installing C library headers: done in 11.10s (at 13:25)
[INFO ]  =================================================================
[INFO ]  Installing static core C compiler
[EXTRA]    Configuring static core C compiler
[EXTRA]    Building static core C compiler
[EXTRA]    Installing static core C compiler
[INFO ]  Installing static core C compiler: done in 134.17s (at 15:39)
[INFO ]  =================================================================
[INFO ]  Installing C library
[EXTRA]    Copying sources to build dir
[EXTRA]    Applying configuration
[EXTRA]    Building C library
[EXTRA]    Installing C library
[INFO ]  Installing C library: done in 15.73s (at 15:55)
[INFO ]  =================================================================
[INFO ]  Installing final compiler
[EXTRA]    Configuring final compiler
[EXTRA]    Building final compiler
[EXTRA]    Installing final compiler
[INFO ]  Installing final compiler: done in 141.78s (at 18:17)
[INFO ]  =================================================================
[INFO ]  Installing libelf for the target
[EXTRA]    Configuring libelf
[EXTRA]    Building libelf
[EXTRA]    Installing libelf
[INFO ]  Installing libelf for the target: done in 6.66s (at 18:24)
[INFO ]  =================================================================
[INFO ]  Installing binutils for target
[EXTRA]    Configuring binutils for target
[EXTRA]    Building binutils' libraries (libiberty bfd) for target
[EXTRA]    Installing binutils' libraries (libiberty bfd) for target
[INFO ]  Installing binutils for target: done in 43.88s (at 19:07)
[INFO ]  =================================================================
[INFO ]  Installing dmalloc
[EXTRA]    Configuring dmalloc
[EXTRA]    Building dmalloc
[EXTRA]    Installing dmalloc
[INFO ]  Installing dmalloc: done in 9.83s (at 19:17)
[INFO ]  =================================================================
[INFO ]  Installing D.U.M.A.
[EXTRA]    Copying sources
[EXTRA]    Building libraries 'libduma.a'
[EXTRA]    Installing libraries 'libduma.a'
[EXTRA]    Installing shared library link
[EXTRA]    Installing wrapper script
[INFO ]  Installing D.U.M.A.: done in 1.94s (at 19:19)
[INFO ]  =================================================================
[INFO ]  Installing cross-gdb
[EXTRA]    Configuring cross-gdb
[EXTRA]    Building cross-gdb
[EXTRA]    Installing cross-gdb
[EXTRA]    Install '.gdbinit' template
[INFO ]  Installing cross-gdb: done in 61.43s (at 20:21)
[INFO ]  =================================================================
[INFO ]  Installing native gdb
[EXTRA]    Building static target ncurses
[EXTRA]    Building static target expat
[EXTRA]    Configuring native gdb
[EXTRA]    Building native gdb
[EXTRA]    Installing native gdb
[EXTRA]    Cleaning up ncurses
[INFO ]  Installing native gdb: done in 133.22s (at 22:34)
[INFO ]  =================================================================
[INFO ]  Installing gdbserver
[EXTRA]    Configuring gdbserver
[EXTRA]    Building gdbserver
[EXTRA]    Installing gdbserver
[INFO ]  Installing gdbserver: done in 6.22s (at 22:40)
[INFO ]  =================================================================
[INFO ]  Installing ltrace
[EXTRA]    Copying sources to build dir
[EXTRA]    Configuring ltrace
[EXTRA]    Building ltrace
[EXTRA]    Installing ltrace
[INFO ]  Installing ltrace: done in 4.17s (at 22:44)
[INFO ]  =================================================================
[INFO ]  Installing strace
[EXTRA]    Configuring strace
[EXTRA]    Building strace
[EXTRA]    Installing strace
[INFO ]  Installing strace: done in 17.68s (at 23:02)
[INFO ]  =================================================================
[INFO ]  Cleaning-up the toolchain's directory
[INFO ]    Stripping all toolchain executables
[EXTRA]    Installing the populate helper
[EXTRA]    Installing a cross-ldd helper
[EXTRA]    Creating toolchain aliases
[EXTRA]    Removing access to the build system tools
[EXTRA]    Removing installed documentation
[INFO ]  Cleaning-up the toolchain's directory: done in 2.25s (at 23:04)
[INFO ]  Build completed at 20110808.235900
[INFO ]  (elapsed: 23:04.20)
[INFO ]  Finishing installation (may take a few seconds)...


Note: typoes are the original author's. ;-)

  • On 20080826.0106+0200, Chris Hinshaw writes:
Thank you for making a non-trivial task simple. CT-NG is an excellent tool
and extremely easy to use. I have been using it to create toolchains for the
405 and it is an unbelievable time saver. Very well designed and implemented.

Thank you,
Chris Hinshaw
  • On 20080915.1614+0200, Peter Wippich writes:
First of all thanks for the nice work. I successfully build a arm9tdmi
toolchain (after some minor problems) with gcc4.2.2 / glibc2.6.
  • On 20081023.2243+0200, Nye Liu writes:
Thanks for your reponse. Let me just say... i am VERY happy with crosstool-ng
so far, thank you so much the time and effort you spent on it, it is simply
  • On 20081123.2019+0100, Дмитрий Барский writes:
We are successfully using your crosstol-ng for creating small embedded
gnu/linux distribution, that we use in ticket selling terminal, slot
machines, online pay terminals and probably will use somewhere else. We've
tried a lot of similar tools, but only this one has clear and user friendly
documentation, and is very easy in use.
  • On 20090131.1807+0100, Vincent Sanders wrote:
Firstly I would like to say thanks for your excellent tool, saves me a
*lot* of time and effort. We use it to generate the cross compielrs
for the ARM linux Linux Kernel autobuilder:
  • On 20090223.1545+0100, Kim B. Heino wrote:
Our company has been using crosstool-NG for some time now. Thanks for
great toolchain builder! Before crosstool-NG we used our own builder.
  • On 20090710.2240+0200, Johns Daniel wrote:
Thank you very much for crosstool-ng! Certainly, a very useful tool
for building cross-compilers.
  • On 20130116.0940+0100, Jérôme BARDON wrote:
We have been using crosstool-NG consistently in our company over 2 years
to produce cross-toolchains for x86_64 targets. These toolchains have
compiled milions of lines of code so far without any problem.
start.txt · Last modified: 20151120.131411 by bhundven
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