Public | Automated Build

Last pushed: 2 years ago
Short Description
Emscripten Javascript cross compiler.
Full Description


Dockerfiles for cross compiling in a Docker container.


  • Different toolchains for cross compiling.
  • Commands in the container are run as the calling user, so that any created files have the expected ownership, (i.e. not root).
  • Make variables (CC, LD etc) are set to point to the appropriate tools in the container.
  • Recent cmake and ninja are precompiled. Toolchain files available for cmake.
  • Current directory is mounted as the container's workdir, /build.
  • Works with boot2docker on OSX and Docker for Mac beta (1.11.1-beta12).


This image is not intended to be run manually. Instead, there is a helper script which comes bundled with the image.

To install the helper script, run one of the images with no arguments, and
redirect the output to a file::

docker run --rm CROSS_COMPILER_IMAGE_NAME > ./dockcross
chmod +x ./dockcross
mv ./dockcross ~/bin/


For the impatient, here's a one-liner to compile a hello world for armv7::

docker run --rm thewtex/cross-compiler-linux-armv7 > ./dockcross-linux-armv7
chmod +x ./dockcross-linux-armv7
./dockcross-linux-armv7 bash -c '$CC test/C/hello.c -o hello_arm'

Note how invoking any toolchain command (make, gcc, etc...) is just a matter of prepending the dockcross script on the commandline::

dockcross-linux-armv7 [command] [args...]

The dockcross script will execute the given command-line inside the container,
along with all arguments passed after the command.

Alternatively, a special update command can be exected that will update the
source cross-compiler Docker image or the dockcross script itself.

Built-in update commands

  • dockcross [--] command [args...]: Forces a command to run inside the container (in case of a name clash with a built-in command), use -- before the command.
  • dockcross update-image: Fetch the latest version of the docker image.
  • dockcross update-script: Update the installed dockcross script with the one bundled in the image.
  • dockcross update: Update both the docker image, and the dockcross script.


The following command-line options and environment variables are used. In all cases, the command-line option overrides the environment variable.

DOCKCROSS_CONFIG / --config|-c <path-to-config-file>

This file is sourced, if it exists, before executing the rest of the dockcross

Default: ~/.dockcross

DOCKCROSS_IMAGE / --image|-i <docker-image-name>

The docker cross-compiler image to run.

Default: image with which the script was created.

DOCKCROSS_ARGS / --args|-a <docker-run-args>

Extra arguments to pass to the docker run command.


  1. dockcross make: Build the Makefile in the current directory.
  2. dockcross cmake -Bbuild -H. -GNinja*: Run CMake with a build directory "build" for the CMakeLists.txt in the current directory and generate ninja files.
  3. dockcross ninja -Cbuild: Run ninja in the generated build directory.
  4. dockcross bash -c 'find . -name *.o | sort > objects.txt'

Note that commands are executed verbatim. If you require any shell processing for environment variable expansion or redirection, please use bash -c 'command args...'.

Credits go to sdt/docker-raspberry-pi-cross-compiler <>_, who invented the base of the dockcross script.

CI status

.. image::

.. |base-images| image::

|base-images| Base image for other toolchain images. From Debian Jessie with GCC,
make, autotools, CMake, Ninja, Git, and Python.

.. |android-arm-images| image::

|android-arm-images| The Android NDK standalone toolchain for the arm

.. |browser-asmjs-images| image::

|browser-asmjs-images| The Emscripten JavaScript cross compiler.

.. |linux-armv5-images| image::

|linux-armv5-images| Linux armv5 cross compiler toolchain for legacy devices
like the Parrot AR Drone.

.. |linux-armv6-images| image::

|linux-armv6-images| Linux ARMv6 cross compiler toolchain for the Raspberry
Pi, etc.

.. |linux-armv7-images| image::

|linux-armv7-images| Generic Linux armv7 cross compiler toolchain.

.. |linux-ppc64le-images| image::

|linux-ppc64le-images| Linux PowerPC 64 little endian cross compiler
toolchain for the POWER8, etc.

.. |linux-x64-images| image::

|linux-x64-images| Linux x86_64 / amd64 compiler. Since the Docker image is
natively x86_64, this is not actually a cross compiler.

.. |linux-x86-images| image::

|linux-x86-images| Linux i686 cross compiler.

.. |windows-x64-images| image::

|windows-x64-images| 64-bit Windows cross-compiler based on MXE/MinGW-w64.

.. |windows-x86-images| image::

|windows-x86-images| 32-bit Windows cross-compiler based on MXE/MinGW-w64.

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