Resources to allow cross compiling WebKit2GTK+ for ARM.

• A host machine with lots of CPUs and RAM (16GB recommended)
• RootFS for the target device
  • You need to adjust the path in the CMake Toolchain file accordingly (e.g /schroot/eos-master-armhf)
• Packages to create and use the chroot: debootstrap, chroot and schroot
  • Debian/Ubuntu: sudo apt-get install debootstrap chroot schroot
  • Fedora: sudo dnf install debootstrap chroot schroot

(1) First of all, create the chroot:

$ sudo /usr/sbin/debootstrap \
    --arch amd64 \
    --components=main,universe \
    xenial /path/to/chroot http://uk.archive.ubuntu.com/ubuntu

(2) Create a configuration file for schroot, for instance under /etc/schroot/chroot.d/xenial-amd64, with the following contents (replacing <username> and <group>):

[xenial-amd64]
description=Ubuntu 64-bit chroot based on Xenial
type=directory
directory=/path/to/chroot
users=<username>
groups=<group>
root-users=<username>
setup.copyfiles=default/copyfiles
setup.fstab=default/xenial-amd64.fstab

(3) Now you need to create that file under /etc/schroot/default so that you can tell schroot to bind mount the path to the RootFS when entering the chroot. To do that, create a copy of /etc/schroot/default/fstab (sudo cp /etc/schroot/default/fstab/xenial-amd64.fstab) and then add this line to its contents:

# To crosscompile WebKitGTK
/schroot/eos-master-armhf  /schroot/eos-master-armhf        none    rw,bind         0       0

...or whatever the path to the RootFS is. Just remember that the second column specifies the mount point inside the chroot, so it has to be on sync with the path referenced from the CMake Toolchain file.

(4) You should be able to enter the chroot with your regular user session:

  $ schroot -c xenial-amd64

(5) Finally, from inside the chroot, you can run the bootstrap.sh script as the root user (or using sudo) provided with this repository to provision it with the tools you need to build Webkit, and then copy the armv7l-toolchain.cmake file to some local path, and you're good to go.

(6) Now create a BUILD directory in /path/to/your/WebKit and configure the build (you might want to pass extra/different parameters, though) from inside the chroot:

  $ mkdir /path/to/your/WebKit/BUILD && cd /path/to/your/WebKit/BUILD
  $ cmake -DCMAKE_TOOLCHAIN_FILE=/home/mario/work/webkit2gtk-ARM/armv7l-toolchain.cmake \
        -DPORT=GTK \
        -DCMAKE_BUILD_TYPE=Release \
        -DCMAKE_INSTALL_SYSCONFDIR=/etc \
        -DCMAKE_INSTALL_LOCALSTATEDIR=/var \
        -DCMAKE_INSTALL_PREFIX=/usr \
        -DCMAKE_INSTALL_LIBDIR=lib/arm-linux-gnueabihf \
        -DCMAKE_INSTALL_LIBEXECDIR=lib/arm-linux-gnueabihf \
        -DENABLE_PLUGIN_PROCESS_GTK2=OFF \
        -DENABLE_GEOLOCATION=OFF \
        -DENABLE_GLES2=ON \
        -DUSE_LD_GOLD=OFF \
        /path/to/your/WebKit

(7) Finally, and still from inside the chroot, build the thing:

  $ make VERBOSE=1 -j12    # Or anything else, this is just what I use

And that should be all. Now you should be able to copy the relevant files over to the target machine and use your cross-compiled WebKit build.

Enjoy!