This section describes the setup needed by various operating systems in order to run crosstool-NG, as well as some OS-specific caveats and limitations. The package lists given in the following subsections cover all the features tested by the sample configurations. You particular configuration may not need all those packages. For example, git is needed if your configuration is for an uClinux-based target which requires elf2flt utilities (which does “rolling releases” and must be checked out from a Git repository).


Sample configurations for supported Linux distributions are available as Docker configuration files in the testing directory. You can use the contents of these files as a list of the packages that need to be installed on a particular distribution.

If on the other hand you encounter a dependency not listed there, please let us know over the mailing list or via a pull request!

Windows: Cygwin

Originally contributed by: Ray Donnelly

Prerequisites and instructions for using crosstool-NG for building a cross toolchain on Windows (Cygwin) as build and, optionally Windows (hereafter) MinGW-w64 as host.

  1. Use Cygwin64 if you can. DLL base-address problems are lessened that way and if you bought a 64-bit CPU, you may as well use it.

  2. You must enable Case Sensitivity in the Windows Kernel (this is only really necessary for Linux targets, but at present, crosstool-ng refuses to operate on case insensitive filesystems). The registry key for this is: HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\kernel\obcaseinsensitive Read more here.

    Since release 1.7, Cygwin no longer supports the ‘managed’ mount option. You must use case sensitive FS.

  3. Using setup.exe or setup-x86_64.exe, install the default packages and also the following ones:
    • autoconf
    • automake
    • bison
    • diffutils
    • flex
    • gawk
    • gcc-g++
    • git
    • gperf
    • help2man
    • libncurses-devel
    • make
    • patch
    • python-devel
    • texinfo
    • wget
    • xz

    Leave “Select required packages (RECOMMENDED)” ticked.


    • The packages marked with * are only needed if your host is MinGW-w64.
  4. Although nativestrict symlinks seem like the best idea, extracting glibc fails when they are enabled, so just don’t set anything here. If your host is MinGW-w64 then these ‘Cygwin-special’ symlinks won’t work, but you can dereference them by using tar options –dereference and –hard-dereference when making a final tarball. I plan to investigate and fix or at least work around the extraction problem. Read more here.

  5. If both BFD and GOLD linkers are enabled in binutils, collect2.exe will attempt to run ld which is a shell script so you need to make sure that a working shell is in your path. Eventually this will be replaced with a native program for MinGW-w64 host.


  1. Cygwin is slow. No, really, really slow. Expect about approximately 5x to 10x slowdown compared to a Linux system.

FreeBSD (and other BSD)

FreeBSD support is currently experimental in crosstool-NG.

FreeBSD does not provide a gcc command by default. Crosstool-NG and many of the packages used expect this by default. A comprehensive fix for various ways of setting up the OS is planned after the 1.23 release. Until then, setting up the following packages is recommended as a prerequisite for crosstool-NG:

  • archivers/zip
  • devel/automake
  • devel/bison
  • devel/gettext-tools
  • devel/git
  • devel/gmake
  • devel/gperf
  • devel/libatomic_ops
  • devel/libtool
  • devel/patch
  • lang/gcc6
  • lang/gawk
  • misc/help2man
  • print/texinfo
  • textproc/asciidoc
  • textproc/gsed
  • textproc/xmlto

Use any supported method of installation, e.g.:

cd /usr/ports/lang/gcc6
make install clean

Even with these packages installed, some of the samples are failing to build. YMMV.

Previous version of the installation guidelines

Contributed by: Titus von Boxberg

Prerequisites and instructions for using ct-ng for building a cross toolchain on FreeBSD as host.

  1. Tested on FreeBSD 8.0

  2. Install (at least) the following ports archivers/lzma textproc/gsed devel/gmake devel/patch shells/bash devel/bison lang/gawk devel/automake110 ftp/wget

    Of course, you should have /usr/local/bin in your PATH.

  3. run ct-ng’s configure with the following tool configuration:
    ./configure --with-sed=/usr/local/bin/gsed \
       --with-make=/usr/local/bin/gmake \
    [...other configure parameters as you like...]
  4. proceed as described in general documentation but use gmake instead of make

macOS (a.k.a Mac OS X, OS X)

Originally contributed by: Titus von Boxberg Updates by: Bryan Hundven

These instructions have been tested on macOS Sonoma (14.3.1). I have not tested on any other version with the following commands. YMMV Currently we only support homebrew. Type any one of these commands: git, clang, or gcc in a terminal, and it will prompt you to install the Xcode Command Line Tools. Follow the instructions on the homebrew website to get homebrew installed. Run brew doctor to make sure everything is setup properly. If you have any problems, please refer to the homebrew website.

  1. Install the following packages:
    autoconf automake bash binutils bison gawk git gnu-sed gnu-tar gettext help2man make ncurses readline wget xz zstd

    Then append the following to your shell’s profile script (~/.profile or ~/.zprofile): ``` BREW_PREFIX=”$(brew –prefix)”

PATH=${PATH}:${BREW_PREFIX}/opt/binutils/bin” PATH=${BREW_PREFIX}/opt/bison/bin:${PATH}” PATH=/Volumes/crosstool-ng/bin:${PATH}” export PATH

LDFLAGS=”-L${BREW_PREFIX}/opt/binutils/lib” LDFLAGS+=” -L${BREW_PREFIX}/opt/bison/lib” LDFLAGS+=” -L${BREW_PREFIX}/opt/ncurses/lib” export LDFLAGS

CPPFLAGS=”-I${BREW_PREFIX}/opt/binutils/include” CPPFLAGS+=” -I${BREW_PREFIX}/opt/ncurses/include” export CPPFLAGS

export PKG_CONFIG_PATH=”${BREW_PREFIX}/share/pkgconfig:${PKG_CONFIG_PATH}”

2. You have to use a case sensitive file system for crosstool-NG's build and target
   directories. Use a disk or disk image with a case sensitive FS that you
   mount somewhere.

cd $HOME hdiutil create -size 40g -fs “Case-sensitive APFS” -type SPARSE -volname crosstool-ng crosstool-ng

   This will create `crosstool-ng.sparseimage`. You can mount it by typing:

cd $HOME hdiutil mount crosstool-ng.sparseimage

   And unmount it by typing:

hdiutil unmount /Volumes/crosstool-ng

3. You can now build crosstool-ng on that volume by cloning the git repo or
   untaring a release in `/Volumes/crosstool-ng` and bootstrapping (only if from
   git) and configuring and building crosstool-ng.

./bootstrap # again, only needed if you got the source from git ./configure –prefix=/Volumes/crosstool-ng make make install ``` Close your terminal app and open it again to get a new shell and verify your enviornment variables are set with env.

You should now be able to make a directory under /Volumes/crosstool-ng to build a toolchain in.