OSS + ELC EU 2026

In a system with "secure boot", you want to lock down most aspects of the system, in particular the bootloader.

On the other hand, implementing A/B updates requires to keep a writable bootloader environment to implement several aspects of A/B updates: adapting the kernel command line to the active partition, counting boot attempts and implementing recovery after deploying a defective update. Without a careful implementation, this could open the door to altering the sequence of boot commands or to introducing unwanted kernel parameters, therefore breaking the security of the bootloader and the rest of the system.

Both secure boot and A/B updates techniques are well documented, but most often without considering their mutual requirements. In this presentation, I will share solutions I found and used in a recent project. I will also share implementation details with U-Boot and the Yocto Project.