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. * Clean separation of build tools, source code, and build artifacts. * 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. * `Conan.io `_ can be used as a package manager. * 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 `_. 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 '$CC test/C/hello.c -o hello'``: Build the *hello.c* file with the compiler identified with the ``CC`` environmental variable in the build environment. 5. ``dockcross bash``: Run an interactive shell in the build environment. Note that commands are executed verbatim. If any shell processing for environment variable expansion or redirection is required, please use `bash -c 'command args...'`. Installation ------------ This image does not need to be run manually. Instead, there is a helper script to execute build commands on source code existing on the local host filesystem. This script is bundled with the image. To install the helper script, run one of the images with no arguments, and redirect the output to a file:: docker run --rm CROSS_COMPILER_IMAGE_NAME > ./dockcross chmod +x ./dockcross mv ./dockcross ~/bin/ Where `CROSS_COMPILER_IMAGE_NAME` is the name of the cross-compiler toolchain Docker instance, e.g. `dockcross/linux-armv7`. Only 64-bit x86_64 images are provided; a 64-bit x86_64 host system is required. Usage ----- For the impatient, here's how to compile a hello world for armv7:: cd ~/src/dockcross docker run --rm dockcross/linux-armv7 > ./dockcross-linux-armv7 chmod +x ./dockcross-linux-armv7 ./dockcross-linux-armv7 bash -c '$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. 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. .. |android-arm64-images| image:: https://images.microbadger.com/badges/image/dockcross/android-arm64.svg :target: https://microbadger.com/images/dockcross/android-arm64 dockcross/android-arm64 |android-arm64-images| The Android NDK standalone toolchain for the arm64 architecture. .. |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-armv5-musl-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-armv5-musl.svg :target: https://microbadger.com/images/dockcross/linux-armv5-musl dockcross/linux-armv5-musl |linux-armv5-musl-images| Linux armv5 cross compiler toolchain using `musl `_ as base "libc". .. |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-armv7a-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-armv7a.svg :target: https://microbadger.com/images/dockcross/linux-armv7a dockcross/linux-armv7a |linux-armv7a-images| Toolchain configured for ARMv7-A used in Beaglebone Black single board PC with TI SoC AM3358 on board, Cortex-A8. .. |linux-mipsel-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-mipsel.svg :target: https://microbadger.com/images/dockcross/linux-mipsel dockcross/linux-mipsel |linux-mipsel-images| Linux mipsel cross compiler toolchain for little endian MIPS GNU systems. .. |linux-mips-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-mips.svg :target: https://microbadger.com/images/dockcross/linux-mips dockcross/linux-mips |linux-mips-images| Linux mips cross compiler toolchain for big endian 32-bit hard float MIPS GNU systems. .. |linux-s390x-images| image:: https://images.microbadger.com/badges/image/dockcross/linux-s390x.svg :target: https://microbadger.com/images/dockcross/linux-s390x dockcross/linux-s390x |linux-s390x-images| Linux s390x cross compiler toolchain for S390X GNU systems. .. |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. .. |manylinux2014-x64-images| image:: https://images.microbadger.com/badges/image/dockcross/manylinux2014-x64.svg :target: https://microbadger.com/images/dockcross/manylinux2014-x64 dockcross/manylinux2014-x64 |manylinux2014-x64-images| Docker `manylinux2014 `_ image for building Linux x86_64 / amd64 `Python wheel packages `_. It includes Python 2.7, 3.4, 3.5, 3.6, 3.7 and 3.8. Also has support for the dockcross script, and it has installations of CMake, Ninja, and `scikit-build `_. For CMake, it sets `MANYLINUX2014` to "TRUE" in the toolchain. .. |manylinux2014-aarch64-images| image:: https://images.microbadger.com/badges/image/dockcross/manylinux2014-aarch64.svg :target: https://microbadger.com/images/dockcross/manylinux2014-aarch64 dockcross/manylinux2014-aarch64 |manylinux2014-aarch64-images| Docker `manylinux2014 `_ image for building Linux aarch64 / arm64 `Python wheel packages `_. It includes Python 2.7, 3.4, 3.5, 3.6, 3.7 and 3.8. Also has support for the dockcross script, and it has installations of CMake, Ninja, and `scikit-build `_. For CMake, it sets `MANYLINUX2014` to "TRUE" in the toolchain. .. |manylinux2010-x64-images| image:: https://images.microbadger.com/badges/image/dockcross/manylinux2010-x64.svg :target: https://microbadger.com/images/dockcross/manylinux2010-x64 dockcross/manylinux2010-x64 |manylinux2010-x64-images| Docker `manylinux2010 `_ image for building Linux x86_64 / amd64 `Python wheel packages `_. It includes Python 2.7, 3.4, 3.5, 3.6, 3.7 and 3.8. Also has support for the dockcross script, and it has installations of CMake, Ninja, and `scikit-build `_. For CMake, it sets `MANYLINUX2010` to "TRUE" in the toolchain. .. |manylinux2010-x86-images| image:: https://images.microbadger.com/badges/image/dockcross/manylinux2010-x86.svg :target: https://microbadger.com/images/dockcross/manylinux2010-x86 dockcross/manylinux2010-x86 |manylinux2010-x86-images| Docker `manylinux2010 `_ image for building Linux i686 `Python wheel packages `_. It includes Python 2.7, 3.4, 3.5, 3.6, 3.7 and 3.8. Also has support for the dockcross script, and it has installations of CMake, Ninja, and `scikit-build `_. For CMake, it sets `MANYLINUX2010` to "TRUE" in the toolchain. .. |manylinux1-x64-images| image:: https://images.microbadger.com/badges/image/dockcross/manylinux1-x64.svg :target: https://microbadger.com/images/dockcross/manylinux1-x64 dockcross/manylinux1-x64 |manylinux1-x64-images| Docker `manylinux1 `_ image for building Linux x86_64 / amd64 `Python wheel packages `_. It includes Python 2.7, 3.4, 3.5, 3.6, 3.7 and 3.8. Also has support for the dockcross script, and it has installations of CMake, Ninja, and `scikit-build `_. For CMake, it sets `MANYLINUX1` to "TRUE" in the toolchain. .. |manylinux1-x86-images| image:: https://images.microbadger.com/badges/image/dockcross/manylinux1-x86.svg :target: https://microbadger.com/images/dockcross/manylinux1-x86 dockcross/manylinux1-x86 |manylinux1-x86-images| Docker `manylinux1 `_ image for building Linux i686 `Python wheel packages `_. It includes Python 2.7, 3.4, 3.5, 3.6, 3.7 and 3.8. Also has support for the dockcross script, and it has installations of CMake, Ninja, and `scikit-build `_. For CMake, it sets `MANYLINUX1` to "TRUE" in the toolchain. .. |web-wasm-images| image:: https://images.microbadger.com/badges/image/dockcross/web-wasm.svg :target: https://microbadger.com/images/dockcross/web-wasm dockcross/web-wasm |web-wasm-images| The Emscripten WebAssembly/asm.js/JavaScript cross compiler. .. |windows-static-x64-images| image:: https://images.microbadger.com/badges/image/dockcross/windows-static-x64.svg :target: https://microbadger.com/images/dockcross/windows-static-x64 dockcross/windows-static-x64 |windows-static-x64-images| 64-bit Windows cross-compiler based on `MXE/MinGW-w64`_ with win32 threads and static linking. .. |windows-static-x64-posix-images| image:: https://images.microbadger.com/badges/image/dockcross/windows-static-x64-posix.svg :target: https://microbadger.com/images/dockcross/windows-static-x64-posix dockcross/windows-static-x64-posix |windows-static-x64-posix-images| 64-bit Windows cross-compiler based on `MXE/MinGW-w64`_ with posix threads and static linking. .. |windows-static-x86-images| image:: https://images.microbadger.com/badges/image/dockcross/windows-static-x86.svg :target: https://microbadger.com/images/dockcross/windows-static-x86 dockcross/windows-static-x86 |windows-static-x86-images| 32-bit Windows cross-compiler based on `MXE/MinGW-w64`_ with win32 threads and static linking. .. |windows-shared-x64-images| image:: https://images.microbadger.com/badges/image/dockcross/windows-shared-x64.svg :target: https://microbadger.com/images/dockcross/windows-shared-x64 dockcross/windows-shared-x64 |windows-shared-x64-images| 64-bit Windows cross-compiler based on `MXE/MinGW-w64`_ with win32 threads and dynamic linking. .. |windows-shared-x64-posix-images| image:: https://images.microbadger.com/badges/image/dockcross/windows-shared-x64-posix.svg :target: https://microbadger.com/images/dockcross/windows-shared-x64-posix dockcross/windows-shared-x64-posix |windows-shared-x64-posix-images| 64-bit Windows cross-compiler based on `MXE/MinGW-w64`_ with posix threads and dynamic linking. .. |windows-shared-x86-images| image:: https://images.microbadger.com/badges/image/dockcross/windows-shared-x86.svg :target: https://microbadger.com/images/dockcross/windows-shared-x86 dockcross/windows-shared-x86 |windows-shared-x86-images| 32-bit Windows cross-compiler based on `MXE/MinGW-w64`_ with win32 threads and dynamic linking. Articles -------- - `dockcross: C++ Write Once, Run Anywhere `_ - `Cross-compiling binaries for multiple architectures with Docker `_ 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 Dockcross 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. Per-project dockcross configuration ----------------------------------- If a shell script named ``.dockcross`` is found in the current directory where the dockcross script is started, it is executed before the dockcross script ``command`` argument. The shell script is expected to have a shebang like ``#!/usr/bin/env bash``. For example, commands like ``git config --global advice.detachedHead false`` can be added to this script. How to extend Dockcross images ------------------------------ In order to extend Dockcross images with your own commands, one must: 1. Use ``FROM dockcross/``. 2. Set ``DEFAULT_DOCKCROSS_IMAGE`` to a name of the tag you're planning to use for the image. This tag must then be used during the build phase, unless you mean to pass the resulting helper script the ``DOCKCROSS_IMAGE`` argument. An example Dockerfile would be:: FROM dockcross/linux-armv7 ENV DEFAULT_DOCKCROSS_IMAGE my_cool_image RUN apt-get install nano And then in the shell:: docker build -t my_cool_image . # Builds the dockcross image. docker run my_cool_image > linux-armv7 # Creates a helper script named linux-armv7. chmod +x linux-armv7 # Gives the script execution permission. ./linux-armv7 bash # Runs the helper script with the argument "bash", which starts an interactive container using your extended image. What is the difference between `dockcross` and `dockbuild` ? ------------------------------------------------------------ The key difference is that `dockbuild `_ images do **NOT** provide a `toolchain file `_ but they use the same method to conveniently isolate the build environment as `dockcross `_. `dockbuild` is used to build binaries for Linux x86_64 / amd64 that will work across most Linux distributions. `dockbuild` performs a native Linux build where the host build system is a Linux x86_64 / amd64 Docker image (so that it can be used for building binaries on any system which can run Docker images) and the target runtime system is Linux x86_x64 / amd64. `dockcross` is used to build binaries for many different platforms. `dockcross` performs a cross compilation where the host build system is a Linux x86_64 / amd64 Docker image (so that it can be used for building binaries on any system which can run Docker images) and the target runtime system varies. --- Credits go to `sdt/docker-raspberry-pi-cross-compiler `_, who invented the base of the **dockcross** script. .. _MXE/MinGW-w64: https://mxe.cc/