Kernel-from-scratch

Table of Contents

• Overview
• Features
• Architecture
• Usage
• Build and Testing
• Demo
• Roadmap
• Contact Me

Overview

I believe in learning by doing, so to sharpen my C programming skills and deepen my understanding of low-level operations, I started this simple kernel-from-scratch project.

This repository documents my hands-on journey into operating system development, beginning from the basics and incrementally building up fundamental kernel features. It’s a practical exploration of topics such as bootloaders, memory management, hardware interaction, and more—all implemented in C (and some Assembly).

This project is not only educational, but also satisfies a deeper, lifelong fascination with computers that has captivated me since childhood.

Kernel-from-scratch was created to:

• Learn Computer Architecture: Gain hands-on experience with how operating systems interact with hardware.
• Practice Low-Level Programming: Develop skills in C programming and Assembly by implementing essential OS components.
• Explore OS Internals: Delve into bootloading, memory management, and driver development as part of an experimental kernel project.

While this is primarily a personal learning journey, the repository is structured and documented to serve as a resource for anyone interested in OS development and low-level programming.

Features

• GRUB Bootloader Integration: Supports booting via the GRUB bootloader.
• VGA Driver: Implements a basic VGA text mode driver for display output.
• Global Descriptor Table (GDT): Sets up memory segmentation crucial for x86 architectures.
• Modular Code Structure: Organized into clear directories for boot components, kernel code, and supporting libraries.
• Build Automation: Uses a Makefile and linker script (linker.ld) to automate the build process.
• Pre-built ISO Image: Provides a GOOS.iso file for quick testing using emulators like QEMU.

Architecture

The repository is organized as follows:

.
├── .vscode/             # VS Code settings for a consistent development environment.
├── GOOS/boot/           # Bootloader components and boot scripts.
├── build/               # Build scripts and intermediary build artifacts.
├── src/                 # Main source code: kernel core, drivers, and libraries.
├── GOOS.iso             # Pre-built ISO image for testing the operating system.
├── Makefile             # Build automation script.
├── boot.bin             # Bootloader binary.
└── linker.ld            # Linker script defining the memory layout.

Detailed Breakdown

• Bootloader: Located in the GOOS/boot/ directory, responsible for initializing hardware and booting the OS using GRUB.
• Kernel Core: Found in src/, it includes system initialization, basic I/O, and memory management routines.
• Drivers and Libraries: Implements essential drivers (e.g., VGA) and utility functions to support core functionality.
• Build System: The Makefile automates compilation and linking, ensuring reproducible builds. The linker script defines memory sections and layout.

Prerequisites

• Unix-like environment (Linux, macOS, or Windows with WSL)
• GNU Make
• GCC (or a compatible C compiler)
• NASM (for assembly code)
• QEMU (or another emulator) for testing the ISO

Cloning the Repository

Clone the repository to your local machine:

git clone https://github.com/AbdulrahmanGODA/Kernel-from-scratch.git
cd Kernel-from-scratch

Building the Kernel

Run the following command to build the project:

make

This will compile the source code and generate the GOOS.iso image.

Usage

Test the operating system using an emulator like QEMU:

qemu-system-x86_64 -cdrom GOOS.iso

The OS should boot, displaying output via the VGA text mode driver.

Build and Testing

• Automated Builds: Consider setting up GitHub Actions or another CI tool for automated building and testing.
• Debugging: Enable debug flags in the Makefile and use GDB with QEMU for step-by-step debugging where necessary.

Demo

https://drive.google.com/drive/folders/1rt9n40fLjpFTAW9mnXefthCm9n4aec7_?usp=drive_link

Roadmap

Future enhancements include:

• Advanced Memory Management: Implementing more sophisticated memory handling techniques.
• Process Scheduling: Adding basic multitasking support.
• File System Integration: Exploring rudimentary file system support.
• Additional Drivers: Expanding hardware support through new driver implementations.
• Enhanced Documentation: Further improving documentation and code comments for clarity.

Contact Me

If you encounter an issue, have a question, or need clarification about this project, feel free to open an issue on this repository.
You can also reach out to me directly via LinkedIn or Email: abdulrahmangoda@hotmail.com.

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Happy Coding and Learning!

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