Tilck: A tiny Linux-compatible kernel

Nice! Looks like an interesting mid-point between xv6 (modern reimplementation of Sixth Edition Unix from 1975 e.g. Lion book) and a full Linux kernel. Great to see it runs on the LicheeRV Nano, a $9 RISC-V board with 1.0 GHz 64 bit CPU (C906) with MMU, FPU, 128 bit vector unit (RVV draft 0.7.1) and 256 MB of in-package DDR3. That's comparable to a midlife Pentium III or PowerPC G4. It should be a very easy port to the Milk-V…

A Linux-compatible kernel under a BSD license is intriguing :) Jokes aside, this looks great as an educational project, because you can run real Linux software on this kernel, from Vim to Doom. Things will become really interesting once this gets ported to ARM. There is a serious amount of MCUs with 4 MB of RAM where Tilck should run fine, but even Yocto or OpenWRT won't fit.

Any idea why it does require exactly 4MB of RAM, even if kernel is much, much smaller? It's some kind of default size of memory page or what? I asked the same answer here but for normal Linux kernel: https://news.ycombinator.com/item?id=26979499