Raspberry PI

Setup

Note: You only need this if you do not have an existing OpenEmbedded Yocto environment.

create a workspace for your yocto build:

$ mkdir -p rpi-yocto

Inside the newly created directory, initiate the repository

$ repo init -u ssh://[email protected]/WebPlatformForEmbedded/meta-wpe.git -b master -m tools/manifests/rpi-yocto.xml

Fetch and sync all repositories:

$ repo sync

Build

Initiate OE by invoking the oe init script:

$ source poky/oe-init-build-env rpi-ml-build

Add bb layers:

$ bitbake-layers add-layer ../meta-raspberrypi

$ bitbake-layers add-layer ../meta-wpe

$ bitbake-layers add-layer ../meta-openembedded/meta-oe

$ bitbake-layers add-layer ../meta-openembedded/meta-multimedia

$ bitbake-layers add-layer ../meta-openembedded/meta-networking

$ bitbake-layers add-layer ../meta-openembedded/meta-python

Edit conf/local.conf and set the target machine: MACHINE = "raspberrypi3" Remove x11 from Distro features since we use wayland+westeros DISTRO_FEATURES_remove = "x11" Add opengl to Distro Features DISTRO_FEATURES_append = " opengl"

you can use raspberrypi2 as well if you own raspberrypi2 machine.

To set a different GCC e.g. 6.3:

GCCVERSION = "6.%"

Build WPE with Westeros Compositor:

$ bitbake wpe-westeros-image

Install

To flash the sdimg on the sd card:

$ sudo dd if=tmp/deploy/images/raspberrypi3/wpe-westeros-image-raspberrypi3.rpi-sdimg of=/dev/sdX

Optional settings

Use 4.9 kernel (optional), edit conf/local.conf and set:

PREFERRED_VERSION_linux-raspberrypi = "4.9%"

To build without Westeros/Wayland support on RPI (fullscreen EGL), edit conf/local.conf and set:

WPE_BACKEND_rpi  = "rpi"
DISTRO_FEATURES_remove = "wayland"

Note WPE has many other view backends it can use. To select specific setting, like BCM Nexus or IntelCE edit your conf/local.conf and set the WPE_BACKEND = foo directly.

To build an initramfs image, edit conf/local.conf and set:

INITRAMFS_IMAGE_BUNDLE_rpi = "1"
INITRAMFS_IMAGE_rpi = "wpe-initramfs-image"
KERNEL_INITRAMFS = "-initramfs" BOOT_SPACE = "163840"

To install the initram fs, copy the zImage to the fat32 partition of your RPI.