I have been looking at seL4 some more recently, and had a small patch merged today to remove a legacy Python module from a helper script. (I was trying to run the script on a system without that module installed, and it was almost easier to patch it out.) However, the more I think about this code and how it’s used, the more it seems wrong on at least five other levels. ...
Recently I revisited my previous interest in seL4 - a fast, highly assured operating system microkernel for building secure systems. The seL4 Microkit tutorial uses a simple Wordle game example to teach the basics of seL4 Microkit (formerly known as the seL4 Core Platform), which is a framework for creating static embedded systems on top of the seL4 microkernel. Microkit is also at the core of LionsOS, a new project to make seL4 accessible to a wider audience. ...
Several references exist that document how to run seL4 on the Raspberry Pi 3 in 32-bit mode. One annoying paper cut encountered when getting this working is the need for a custom u-boot - either a binary distributed by the authors of seL4, or reverting a particular commit in u-boot. A recent release of seL4 mentioned AArch64 support for RPi3. I’ve got it running, and it appears to avoid the need for a custom u-boot. (N.B. you still need a GPIO serial cable!) ...