Is this what you’re looking for?

The CPRS is one glaring example.

Is you don’t mind, I would be very interested in written formats.

Second buildroot as the way to go. This is what I use to build systems for single application touchscreen HMIs. It’s dead simple too, unless you’re messing with a custom kernel config and/ or using obscure hardware without ready made device tree blobs.

“Bang-Bang”, the simplest feedback controller in control theory.