“What I cannot create, I do not understand.” — Richard Feynman

This little book contains a series of projects based on egos-2000. The mission is to help students gain experience and confidence in creating their own operating system or similar computer systems in their future career.

Core projects

There are 6 core projects covering most of the OS concepts for an undergraduate-level OS course (e.g., Cornell CS4411). The projects introduce the architectural support for OS one-by-one, which Cornell students found very helpful. For example, students would implement a preemptive scheduler without any knowledge of privilege levels.

	OS concepts	Architectural support
Hello, World!	code, data, heap, stack	user-level ISA
User-level Threads	thread, yield, context switch
Preemptive Scheduler	interrupt and exception handling	control register, timer
System Call	inter-process communication	privilege level
Virtual Memory	process, virtual address space	page table translation
File System	disk block, inode, file, directory

Advanced projects

There are 3 advanced projects for a master-level course (e.g., Cornell CS5411).

	OS concepts	Architectural support
SD Card Driver	synchronous I/O	bus, memory-mapped I/O
Ethernet and UDP	asynchronous I/O, TCP/IP	platform-level interrupt controller
Multicore and Lock	mutex, boot loader	atomic memory operation

All the projects can run on the QEMU emulator as well as RISC-V boards. Next, let's get our hands dirty and have fun!