PintOS Operating System

An OS kernel ties together scheduling, memory, I/O, and the file system in ways that only become clear when you implement each subsystem and watch them break each other.

Core kernel subsystems for an x86 OS in C: preemptive thread scheduler, demand-paging virtual memory with clock page replacement and lazy stack initialization, a POSIX-like system call interface, and a multi-level indexed inode file system.

A functional kernel handling page faults, process isolation, and extensible file storage up to 8 MB with constant-time inode access patterns.