If you read Japanese, you might have seen the book “Design and Implementation of Microkernels” by [Seiya Nuda]. An appendix covers how to write your own operating system for RISC-V in a… ...

The purpose of a kernel is to manage the deepest levels of an operating system. It handles requests from hardware devices such as keyboards, schedules tasks, and manages files and memory.

Microsoft shared the kernel source code of the Surface Duo on GitHub recently. The code makes it easier for third-party developers to create custom ROMs for the device.