Overview

Built a custom x86 operating system kernel from scratch as a deep dive into systems programming, CPU architecture, and low-level hardware interaction. The kernel boots directly on bare metal using GRUB and implements fundamental OS concepts.

Key Features

• GRUB Bootloader: Implemented a GRUB-based bootloader that initializes the system and transfers control to the kernel, enabling the OS to boot on any x86-compatible hardware.
• Interrupt Handling (IDT): Designed and implemented the Interrupt Descriptor Table for handling hardware and software interrupts, including keyboard input and timer interrupts.
• Memory Management: Built basic memory management subsystems for kernel-level memory allocation and page management.
• Cooperative Multitasking: Implemented cooperative multitasking with context switching between kernel processes, allowing multiple tasks to share CPU time.
• Hardware Interaction: Low-level hardware interaction using x86 Assembly for direct CPU communication, port I/O, and register manipulation.

Technologies Used

• C++: Kernel logic and higher-level system code
• x86 Assembly: Low-level hardware interaction, boot sequence, and interrupt handlers
• GRUB: Bootloader for system initialization
• Make: Build system for compiling and linking the kernel

Learnings

This project provided hands-on experience with CPU interrupts, context switching, kernel architecture, memory management, and the fundamentals of how operating systems work at the lowest level. Building an OS from scratch gives a perspective on systems that's impossible to get any other way.