Libostree, previous known as OSTree, is both a shared library and suite of command line tools that combines a “git-like” model for committing, downloading and downloading bootable filesystem trees.

Yocto/OpenEmbedded layer meta-updater provides libostree and Aktualizr in Automotive Grade Linux (AGL). Aktualizr is a C++ reference implementation of SOTA OTA update client integrated with libostree.

Although the straight-forward way for doing Software OTA updates in AGL is through ATS Garage, it is also possible to use directly OSTree built with the agl-sota feature and meta-updater.

Required hardware for setting up a demo Raspberry Pi 3:

• Raspberry Pi 3
• microSD card
• Build machine
• Router and a couple of Ethernet cables

For example, the following procedure performs an update of AGL image on Raspberry Pi and adds the simple text editor nano:

• Built AGL image for Raspberry Pi 3 and boot it on the board.
• Add the following line to conf/local.conf to add nano and rebuild the image:

IMAGE_INSTALL_append = " nano "

• On the host, go to directory:

cd tmp/deploy/images/raspberrypi3/ostree_repo

• On the host, start a simple web server:

python -m SimpleHTTPServer 8000

• On the Raspberry Pi 3, configure OSTree remote:

ostree remote add --no-gpg-verify agl http://<host_ip>:8000

• On the Raspberry Pi 3, check for new updates:

ostree pull agl raspberrypi3

• On the Raspberry Pi 3, deploy an update:

ostree admin deploy agl:raspberrypi3

• On the Raspberry Pi 3, reboot the system to apply the update:

systemctl reboot

• On the Raspberry Pi 3, verify that nano has been successfully provided with the update.