I would like to see a very simple OS, built for single-usage, allowing a singular application full control of hardware resources (multi-"threaded", but then let's expose "kernel threads" and "processes" via a rather simple/brutal/direct scheduling API.)

I basically want a simple RTOS and HAL/Driver body. I want timers and clocks. I want some block devices and perhaps file-system-primitives etc. I want TCP/IP and a USB stack. I don't want anything nearly as complex as a Unix, nor need it be Posix compliant etc. I would like it to be runnable from uboot, as it's ARM time now, and arm64 support should be a given.

I would think there is a substantial market for a minimalistic ultra-simple braindead-easy alternative to the "embedded linux" (LOL) wave that seems to be proliferating on all "a" class arm processors...

i need determinacy more than thoroughput, but a 64k ram microcontroller with 500mips isn't going to cut it either. there is a serious hole in the OS market for CPU's where *nix is overkill or unsuitable (and no, RTAI nor a realtime patched kernel count. the complexity of the entire codebase is still there)

I've heard about MirageOS from the oCaml people, but I have not been able to find out any info about timing and concurrency etc...

any info on edgy projects highly appreciated, please!