cross-compilers

Dockerfiles for cross compiling in a Docker container.

Features

different toolchains for cross compiling
commands in the container are run as the calling user, so that any created files have the expected ownership (ie. not root)
make variables (CC, LD etc) are set to point to the appropriate tools in the container
cmake and ninja are precompiled available with a toolchain file 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)

Installation

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 the image with no arguments, and redirect the output to a file:

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

Usage

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

docker run thewtex/cross-compiler-linux-armv7 > dockcross && chmod +x dockcross && ./dockcross gcc test/C/hello.c -o hello_arm

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

dockcross [command] [args...]

Dockcross will thus execute the given command-line inside the container, along with all arguments passed after the command.

Alternatively, if the command matches one of the dockcross built-in commands (see below), that will be executed locally.

Built-in 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.

Configuration

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

### DOCKCROSS_CONFIG / --config <path-to-config-file>

This file is sourced if it exists.

Default: ~/.dockcross

### DOCKCROSS_IMAGE / --image <docker-image-name>

The docker image to run.

Default: thewtex/cross-compiler-linux-armv7

### DOCKCROSS_ARGS / --args <docker-run-args>

Extra arguments to pass to the docker run command.

Examples

dockcross make: Build the Makefile in the current directory.
dockcross cmake -Bbuild -H. -GNinja*: Run CMake with a build directory "build" for the CMakeLists.txt in the current directory and generate ninja files.
dockcross ninja -Cbuild: Run ninja in the generated build directory.
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...'.

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

CI status

thewtex/cross-compiler-base: Base image for other toolchain images. From Debian Jessie with GCC, make, autotools, CMake, Ninja, Git, and Python.
thewtex/cross-compiler-android-arm: The Android NDK standalone toolchain for the arm architecture.
thewtex/cross-compiler-browser-asmjs: The Emscripten JavaScript cross compiler.
thewtex/cross-compiler-linux-armv6: Linux ARMv6 cross compiler toolchain for the Raspberry Pi, etc.
thewtex/cross-compiler-linux-armv7: Generic Linux armv7 cross compiler toolchain.
thewtex/cross-compiler-linux-ppc64le: Linux PowerPC 64 little endian cross compiler toolchain for the POWER8, etc.
thewtex/cross-compiler-linux-x64: Linux x86_64 / amd64 compiler. Since the Docker image is natively x86_64, this is not actually a cross compiler.
thewtex/cross-compiler-linux-x86: Linux i686 cross compiler.
thewtex/cross-compiler-windows-x64: 64-bit Windows cross-compiler based on MXE/MinGW-w64.
thewtex/cross-compiler-windows-x86: 32-bit Windows cross-compiler based on MXE/MinGW-w64.

thewilli / cross-compilers