GenOS A Rust operating system from bootloader to desktop

overview

GenOS is an experimental operating system written in Rust without Linux underneath it. The repository owns the path from firmware handoff to the pixels on screen: a UEFI bootloader loads the kernel and initrd, the kernel establishes memory and interrupt infrastructure, and the system opens into a native desktop with applications, input, storage, and process controls.

problem

Production operating systems carry enormous compatibility and integration contracts. That capability makes the full path from input event to rendered frame difficult to understand. GenOS explores the opposite starting point: a small, coherent system where every subsystem earns its complexity and remains traceable by one developer.

approach

I built the system in measurable layers: repo-owned UEFI boot, bounded ELF loading, gap-safe frame allocation, protected page tables, timer-preempted ring-3 processes, a versioned syscall ABI, capability-scoped VFS handles, PS/2 input, backbuffered rendering, and desktop applications backed by real kernel state. Serial diagnostics and long-running QEMU smoke tests make low-level progress reproducible.

outcome

The current developer preview boots into a working framebuffer desktop and runs separately built userspace programs in isolated address spaces. Applications can sleep, wait, fault, exit, read, and perform bounded writes without receiving authority over the whole filesystem. It is deliberately honest about being experimental while already proving a substantial vertical slice of a real OS.

selected details

• Repo-owned x86_64 UEFI loader and Rust no_std kernel
• Timer-preempted ring-3 processes with separate address spaces and fault isolation
• ABI 7 capability-based VFS reads and bounded writes with frame reclamation
• Native desktop, taskbar, shell, Files, Task Manager, input, clock, and window controls