Patchworkos: An Os For X86_64, Built From Scratch In C And Assembly

A modular, non-POSIX operating system for x86_64, built from scratch in C and assembly. Intended to be an educational and experimental project that rigorously follows a Plan9-style "everything is a file" philosophy, featuring a from-scratch ACPI AML parser, EEVDF scheduler and a focus on unique solutions over tried-and-tested ones.

PatchworkOS is a modular non-POSIX operating system for the x86_64 architecture that rigorously follows an "everything is a file" philosophy, in the style of Plan9. Built from scratch in C and assembly, its intended to be an educational and experimental operating system.

In the end this is a project made for fun, but the goal is to make a "real" operating system, one that runs on real hardware and has the performance one would expect from a modern operating system without jumping ahead to user space features, a floppy disk driver and a round-robin scheduler is not enough.

Also, this is not a UNIX clone, its intended to be a (hopefully) interesting experiment in operating system design by attempting to use unique algorithms and designs over tried and tested ones. Sometimes this leads to bad results, and sometimes, with a bit of luck, good ones.

Finally, despite its experimental nature and scale, the project aims to remain approachable and educational, something that can work as a middle ground between fully educational operating systems like xv6 and production operating system like Linux.

Will this project ever reach its goals? Probably not, but thats not the point.

As one of the main goals of PatchworkOS is to be educational, I have tried to document the codebase as much as possible along with providing citations to any sources used. Currently, this is still a work in progress, but as old code is refactored and new code is added, I try to add documentation.

If you are interested in knowing more, then you can check out the Doxygen generated documentation. For an overview check the topics section in the sidebar.

PatchworkOS uses a "modular" kernel design, meaning that instead of having one big kernel binary, the kernel is split into several smaller "modules" that can be loaded and unloaded at runtime. In effect, the kernel can rewrite itself by adding and removing functionality as needed.

This is highly convenient for development but it also has practical advantages, for example, there is no need to load a driver for a device that is not attached to the system, saving memory.

Source: HackerNews