karion_os
A bare-metal x86 OS kernel written in Rust. Unix-like shell, block filesystem, text editor, BASIC interpreter, and built-in games. Ported from C — the borrow checker caught data races the original never would.
Architecture
Karion-OS is a Unix-like operating system kernel for x86, written entirely in Rust (originally started in C). It runs on bare metal — no bootloader dependencies, no UEFI shims, no GRUB — just a BIOS boot sector that loads the kernel into memory and jumps to it.
Components
- Bootloader — Minimal 512-byte boot sector in assembly that loads the kernel from disk
- Memory Management — Physical memory manager (bitmap-based), paging with recursive page tables
- Interrupt Handling — GDT, IDT, PIC, and interrupt service routines
- VGA Driver — Text-mode framebuffer with scrolling and colored output
- Keyboard Driver — PS/2 interrupt-driven input with scancode translation
- Shell — Unix-like command interpreter with built-in commands
- Filesystem — Block-based filesystem with directory support
- Text Editor — In-kernel text editor for file editing
- BASIC Interpreter — A simple BASIC interpreter running in kernel mode
- Games — Snake, Pong, and other terminal games
Why Rust?
The original C implementation had three recurring bug classes:
- Buffer overflows in ring buffers and string operations
- Silent memory leaks from the heap allocator
- Data races between interrupt handlers and kernel code
Rust’s ownership model eliminated 2 and 3 at compile time. The C port took roughly a week — the architecture stayed the same, but the safety guarantees shifted from “I hope I got this right” to “the compiler won’t let me get it wrong.”
Building
git clone https://github.com/dev-dami/Karion-OS
cd Karion-OS
makeRequires nasm, a cross-compiled Rust target for i686-unknown-none, and QEMU for testing.
Blog
Read about the C-to-Rust port in I Rewrote My OS Kernel in Rust.