BoF: Multibuild for Zephyr RTOS

The Zephyr RTOS build system currently supports generating a single application image. This build is isolated from other related images, such as bootloaders, secure vs. nonsecure Arm TrustZone images, …

The Zephyr RTOS build system currently supports generating a single application image. This build is isolated from other related images, such as bootloaders, secure vs. nonsecure Arm TrustZone images, multi-core applications communicating via IPC mechanisms, etc.This is a problem because these images can be interdependent in ways that require compatible configurations between images (including Kconfig, device tree chosen nodes, linker script memory layout, etc.). Since the build system is agnostic to other images, this is left to the application developer or system designer to manage. That’s unnecessarily error prone, since the build system could check for common errors itself if only it knew about all the executables in the system.Different Zephyr downstream distributions have solved this problem in different ways, but there’s so far no consensus on how to solve this problem upstream. This BoF is meant to keep the conversation going among anyone who is interested in this topic.