Weston on Raspberry Pi

This is a guide for installing Weston into Raspberry Pi. All commands and compiling are done directly on the Pi.

Build dependencies

Assuming you are using the Raspbian distribution, install the build dependencies:

    $ sudo apt-get install build-essential automake libtool bison flex \
    xutils-dev libcairo2-dev libffi-dev libmtdev-dev libjpeg-dev \
    libudev-dev libxcb-xfixes0-dev libxcursor-dev

Firmware

Make sure you have the latest Raspberry Pi firmware with the rpi-update tool. A too old firmware may cause rpi-backend to malfunction on Raspberry Pi.

You may want to tweak the following options in /boot/config.txt:

gpu_mem=128

How much memory to reserve for the VideoCore, i.e. framebuffers, GL textures, Dispmanx resources.

dispmanx_offline=1

This will enable the firmware to fall back to off-line compositing of Dispmanx elements. Normally the compositing is done on-line, during scanout, but cannot handle too many elements. With off-line enabled, an off-screen buffer is allocated for compositing. When scene complexity (number and sizes of elements) is high, compositing will happen off-line into the buffer.

By default, the rpi-backend is configured for the dispmanx_offline=1 case. Without this setting, it would be better to run Weston with --max-planes=10 command line option.

If you want to use Weston with purely GLESv2 compositing, you can pass --max-planes=0 to Weston. In that case it would be preferrable to not set dispmanx_offline=1 to conserve VideoCore memory.

Setting up the environment

Here we will install to the home directory of the pi user.

export WLD="$HOME/local"
export PATH="$WLD/bin:$PATH"
export LD_LIBRARY_PATH="$WLD/lib:/opt/vc/lib"
export PKG_CONFIG_PATH="$WLD/lib/pkgconfig/:$WLD/share/pkgconfig/"
export ACLOCAL="aclocal -I $WLD/share/aclocal"
export XDG_RUNTIME_DIR="/run/shm/wayland"
export XDG_CONFIG_HOME="$WLD/etc"

mkdir -p "$WLD/share/aclocal"
mkdir -p "$XDG_RUNTIME_DIR"

You may put the above in a script and source it in the terminal where you wish to build the packages or run Weston.

pkg-config files

Some libraries on the Pi do not have appropriate pkg-config files installed. We need to install them.

Download the .pc files from git://git.collabora.co.uk/git/user/pq/android-pc-files.git and make sure you take the raspberrypi branch. The master branch contains similar files for Android, and will not work.

Copy the .pc files into $WLD/share/pkgconfig/:

    $ cp bcm_host.pc egl.pc glesv2.pc $WLD/share/pkgconfig/

Wayland libraries

Libwayland is built and installed the same way as in the generic build guide.

    $ git clone git://anongit.freedesktop.org/wayland/wayland
    $ cd wayland
    $ ./autogen.sh --prefix=$WLD
    $ make
    $ make install

libxkbcommon

Libxkbcommon is built and installed the same way as in the generic build guide, too.

    $ git clone git://people.freedesktop.org/xorg/lib/libxkbcommon.git
    $ cd libxkbcommon/
    $ ./autogen.sh --prefix=$WLD
    $ make && make install

Weston and demo applications

Weston is configured slightly differently compared to the normal build:

    $ git clone git://anongit.freedesktop.org/wayland/weston
    $ cd weston

    $ ./autogen.sh --prefix=$WLD \
    --disable-setuid-install --with-cairo-glesv2 \
    --disable-x11-compositor --disable-drm-compositor \
    --disable-android-compositor --disable-wayland-compositor \
    --disable-weston-launch --disable-simple-egl-clients \
    --disable-fbdev-compositor \
    WESTON_NATIVE_BACKEND="rpi-backend.so"

    $ make
    $ make install

When adding --disable-wayland-compositor you can remove the dummy wayland-egl.pc pkg-config file, if you installed it before. This makes sure, that toytoolkit (Weston demo programs) does not use Cairo EGL. EGL does not work for clients due to EGL Wayland platform being unimplemented on Raspberry Pi.

Weston should work by running weston. Remember to have the environment set up.

Troubleshooting

Missing bcm_host.pc

checking for RPI_BCM_HOST... no
configure: WARNING: Raspberry Pi BCM host libraries not found, will use stubs instead.

If the right pkg-config files are not installed, building weston can fail. If you see the above during Weston's configure step, the bcm_host.pc file was not found, and the rpi-backend will not work. The following is what you should see:

checking for RPI_BCM_HOST... yes

Build error: undefined reference to `wl_egl_...

Somehow, cairo-egl is getting used, when it should not. Remove the dummy wayland-egl.pc, and make sure --disable-wayland-compositor is in the configure line. When everything is right, you should see:

checking for CAIRO_EGL... no
configure: WARNING: clients will use cairo image, cairo-egl not used

Some or all surfaces (graphics) are corrupted

Too old firmware might cause corrupted graphics. If you don't want to update the firmware, a workaround is to add --max-planes=0 to the Weston command line. This forces everything to be composited with GLESv2.