Cornell has a 2000 line educational operating system called EGOS (egos-2000 on GitHub) designed by professor Robert van Renesse. It has memory paging, virtual address translation, interrupt handling, process scheduling, system calls, and can run on QEMU or RISC-V.
Previously, 2023, 19 comments: https://news.ycombinator.com/item?id=35982037
There are updates in the last several months, so it looks like the project is still active.
Cornell has a 2000 line educational operating system called EGOS (egos-2000 on GitHub) designed by professor Robert van Renesse. It has memory paging, virtual address translation, interrupt handling, process scheduling, system calls, and can run on QEMU or RISC-V.