Operating systems are the invisible engines behind every computer, smartphone, and smart device, yet many people take them ...

Building a complete operating system in so few lines of code is an impressive feat, and making it comprehensive enough to teach students with goes well beyond that accomplishment as well.

An appendix covers how to write your own operating system for RISC-V in about 1,000 lines of code. Don’t speak Japanese? An English version is available free on the Web and on GitHub.