Operating Systems Projects

A collection of three operating systems projects covering Linux kernel development, thread scheduling, and kernel module programming on RISC-V/Linux environments.

Repository Overview

This repository contains three mini-projects completed as part of an Operating Systems course. Each project focuses on a different systems programming topic:

1. RISC-V Kernel Syscalls
   Built and modified a custom Linux kernel on RISC-V, and implemented two custom system calls: revstr and tempbuf.

2. Linux Thread Scheduling Demo
   Developed a multithreaded scheduling demo to compare Linux scheduling policies such as SCHED_NORMAL and SCHED_FIFO, using CPU affinity, barriers, and priority settings.

3. Kfetch Kernel Module
   Implemented a Linux kernel module that provides a simple kfetch-style interface through a character device, allowing configurable system information output.

Repository Structure

Operating-Systems-Projects/
├── README.md
├── riscv-kernel-syscalls/
│   ├── README.md
│   ├── patches/
│   └── config/
├── linux-thread-scheduling-demo/
│   ├── README.md
│   ├── Makefile
│   └── sched_demo.c
└── kfetch-kernel-module/
    ├── README.md
    ├── Makefile
    └── kfetch_mod.c

Project Details

1. RISC-V Kernel Syscalls

This project focuses on Linux kernel compilation and syscall implementation on a RISC-V environment.

Key topics

• Building a custom Linux kernel for RISC-V
• Booting with QEMU
• Adding custom syscalls to the kernel
• Kernel-space buffer handling and string processing

Implemented syscalls

• revstr: reverses a user-provided string
• tempbuf: stores and retrieves data through a temporary kernel buffer

2. Linux Thread Scheduling Demo

This project demonstrates how Linux thread scheduling policies affect execution order and runtime behavior.

Key topics

• POSIX threads
• SCHED_NORMAL vs SCHED_FIFO
• Thread priorities
• CPU affinity
• Barrier synchronization
• Busy-wait execution for scheduling observation

3. Kfetch Kernel Module

This project implements a custom Linux kernel module with a kfetch-style interface via a character device.

Key topics

• Linux kernel module development
• Character device registration
• Kernel read/write operations
• Bitmask-based output control
• System information reporting from kernel space

Skills Demonstrated

• Linux kernel development
• System call implementation
• Kernel module programming
• POSIX multithreading
• Linux scheduling policies
• RISC-V cross-compilation
• QEMU-based system testing
• Makefile-based build workflows

Notes

• Each subfolder contains its own README with project-specific details and build instructions.
• Reports are intentionally not included; this repository focuses on source code, configuration, and reproducible project structure.
• Both user-space and kernel-space operating systems programming topics are covered in this repository.