Unix-like Operating System

Project Overview

This is a Unix-like operating system built from scratch for UIUC's OS coursework. The entire OS includes a custom:

• Kernel: Custom kernel with process management, threading, and memory management
• File System: EXT2-like file system implementation with caching
• Device Drivers: UART, RTC, VirtIO block and network devices
• System Calls: Complete syscall interface for user programs
• User Space: Shell and various Unix utilities (cat, ls, echo, wc, etc.)
• Interrupt Handling: Custom interrupt and exception handling
• Virtual Memory: Memory management and heap allocation

Architecture

• Target Platform: RISC-V architecture running on QEMU
• Language: C and RISC-V assembly
• Build System: Make-based build system with debugging support

Directory Structure

• sys/ - Kernel source code and core OS components
• usr/ - User space programs and shell utilities
• util/ - Build utilities and file system generation tools

Building and Running

Use the provided VS Code tasks:

• Build User & Shell: Compiles user programs and generates file systems
• Shell Program Debug Setup: Builds and launches QEMU in debug mode
• run QEMU (debug): Starts QEMU with debugging enabled

Features

• Multi-threaded kernel
• Virtual file system with device abstraction
• Shell with pipes and I/O redirection support
• ELF binary loading
• Timer-based scheduling
• Games included: Rogue, Trek, Zork

TODO

• Push the TCP/IP and vionet drivers
• Add required syscalls for libc