dockcross ========= Cross compiling toolchains in Docker images. .. image:: https://circleci.com/gh/dockcross/dockcross/tree/master.svg?style=svg :target: https://circleci.com/gh/dockcross/dockcross/tree/master Features -------- * Pre-built and configured toolchains for cross compiling. * Most images also contain an emulator for the target system. * 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 configured for CMake. * Current directory is mounted as the container's workdir, ``/work``. * Works with the `Docker for Mac `_ and `Docker for Windows `_. Cross compilers --------------- .. |base-images| image:: https://images.microbadger.com/badges/image/dockcross/base.svg :target: https://microbadger.com/images/dockcross/base dockcross/base |base-images| Base image for other toolchain images. From Debian Jessie with GCC, make, autotools, CMake, Ninja, Git, and Python. .. |android-arm-images| image:: https://images.microbadger.com/badges/image/dockcross/android-arm.svg :target: https://microbadger.com/images/dockcross/android-arm dockcross/android-arm |android-arm-images| The Android NDK standalone toolchain for the arm architecture. .. |browser-asmjs-images| image:: https://images.microbadger.com/badges/image/dockcross/browser-asmjs.svg :target: https://microbadger.com/images/dockcross/browser-asmjs dockcross/browser-asmjs |browser-asmjs-images| The Emscripten JavaScript cross compiler. .. |linux-arm64-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-arm64.svg :target: https://microbadger.com/images/dockcross/linux-arm64 dockcross/linux-arm64 |linux-arm64-images| Cross compiler for the 64-bit ARM platform on Linux, also known as AArch64. .. |linux-armv5-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-armv5.svg :target: https://microbadger.com/images/dockcross/linux-armv5 dockcross/linux-armv5 |linux-armv5-images| Linux armv5 cross compiler toolchain for legacy devices like the Parrot AR Drone. .. |linux-armv6-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-armv6.svg :target: https://microbadger.com/images/dockcross/linux-armv6 dockcross/linux-armv6 |linux-armv6-images| Linux ARMv6 cross compiler toolchain for the Raspberry Pi, etc. .. |linux-armv7-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-armv7.svg :target: https://microbadger.com/images/dockcross/linux-armv7 dockcross/linux-armv7 |linux-armv7-images| Generic Linux armv7 cross compiler toolchain. .. |linux-ppc64le-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-ppc64le.svg :target: https://microbadger.com/images/dockcross/linux-ppc64le dockcross/linux-ppc64le |linux-ppc64le-images| Linux PowerPC 64 little endian cross compiler toolchain for the POWER8, etc. .. |linux-x64-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-x64.svg :target: https://microbadger.com/images/dockcross/linux-x64 dockcross/linux-x64 |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:: https://images.microbadger.com/badges/image/dockcross/linux-x86.svg :target: https://microbadger.com/images/dockcross/linux-x86 dockcross/linux-x86 |linux-x86-images| Linux i686 cross compiler. .. |manylinux-x64-images| image:: https://images.microbadger.com/badges/image/dockcross/manylinux-x64.svg :target: https://microbadger.com/images/dockcross/manylinux-x64 dockcross/manylinux-x64 |manylinux-x64-images| Docker `manylinux `_ image for building Linux x86_64 / amd64 `Python wheel packages `_. Also has support for the dockcross script, and it has installations of CMake, Ninja, and `scikit-build `_ .. |manylinux-x86-images| image:: https://images.microbadger.com/badges/image/dockcross/manylinux-x86.svg :target: https://microbadger.com/images/dockcross/manylinux-x86 dockcross/manylinux-x86 |manylinux-x86-images| Docker `manylinux `_ image for building Linux i686 `Python wheel packages `_. Also has support for the dockcross script, and it has installations of CMake, Ninja, and `scikit-build `_ .. |windows-x64-images| image:: https://images.microbadger.com/badges/image/dockcross/windows-x64.svg :target: https://microbadger.com/images/dockcross/windows-x64 dockcross/windows-x64 |windows-x64-images| 64-bit Windows cross-compiler based on MXE/MinGW-w64. .. |windows-x86-images| image:: https://images.microbadger.com/badges/image/dockcross/windows-x86.svg :target: https://microbadger.com/images/dockcross/windows-x86 dockcross/windows-x86 |windows-x86-images| 32-bit Windows cross-compiler based on MXE/MinGW-w64. Installation ------------ This image does not need to be run manually. Instead, there is a helper script to execute build commands on source code existing on the local host filesystem. This script is 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/ Where `CROSS_COMPILER_IMAGE_NAME` is the name of the cross-compiler toolchain Docker instance, e.g. `dockcross/linux-armv7`. Usage ----- For the impatient, here's how to compile a hello world for armv7:: cd ~/src/dockcross docker run --rm dockcross/linux-armv7 > ./dockcross-linux-armv7 chmod +x ./dockcross-linux-armv7 ./dockcross-linux-armv7 bash -c '$CC test/C/hello.c -o hello_arm' Note how invoking any toolchain command (make, gcc, etc.) is just a matter of prepending the **dockcross** script on the commandline:: ./dockcross-linux-armv7 [command] [args...] The dockcross script will execute the given command-line inside the container, along with all arguments passed after the command. Commands that evaluate environmental variables in the image, like `$CC` above, should be executed in `bash -c`. The present working directory is mounted within the image, which can be used to make source code available in the Docker container. Built-in update commands ------------------------ A special update command can be executed that will update the source cross-compiler Docker image or the dockcross script itself. - ``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. Download all images ------------------- To easily download all images, the convenience target ``display_images`` could be used:: curl https://raw.githubusercontent.com/dockcross/dockcross/master/Makefile -o dockcross-Makefile for image in $(make -f dockcross-Makefile display_images); do echo "Pulling dockcross/$image" docker pull dockcross/$image done Install all dockcross scripts ----------------------------- To automatically install in ``~/bin`` the dockcross scripts for each images already downloaded, the convenience target ``display_images`` could be used:: curl https://raw.githubusercontent.com/dockcross/dockcross/master/Makefile -o dockcross-Makefile for image in $(make -f dockcross-Makefile display_images); do if [[ $(docker images -q dockcross/$image) == "" ]]; then echo "~/bin/dockcross-$image skipping: image not found locally" continue fi echo "~/bin/dockcross-$image ok" docker run dockcross/$image > ~/bin/dockcross-$image && \ chmod u+x ~/bin/dockcross-$image done Configuration ------------- The following environmental variables and command-line options are used. In all cases, the command-line option overrides the environment variable. DOCKCROSS_CONFIG / --config|-c ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This file is sourced, if it exists, before executing the rest of the dockcross script. Default: ``~/.dockcross`` DOCKCROSS_IMAGE / --image|-i ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The Docker cross-compiler image to run. Default: Image with which the script was created. DOCKCROSS_ARGS / --args|-a ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Extra arguments to pass to the ``docker run`` command. Quote the entire set of args if they contain spaces. Examples -------- 1. ``dockcross make``: Build the *Makefile* in the current directory. 2. ``dockcross cmake -Bbuild -H. -GNinja``: Run CMake with a build directory ``./build`` for a *CMakeLists.txt* file in the current directory and generate ``ninja`` build configuration files. 3. ``dockcross ninja -Cbuild``: Run ninja in the ``./build`` directory. 4. ``dockcross bash -c '$CC test/C/hello.c -o hello'``: Build the *hello.c* file with the compiler identified with the ``CC`` environmental variable in the build environment. 5. ``dockcross bash``: Run an interactive shell in the build environment. Note that commands are executed verbatim. If any shell processing for environment variable expansion or redirection is required, please use `bash -c 'command args...'`. Articles -------- - `dockcross: C++ Write Once, Run Anywhere `_ - `Cross-compiling binaries for multiple architectures with Docker `_ --- Credits go to `sdt/docker-raspberry-pi-cross-compiler `_, who invented the base of the **dockcross** script.