Hello, Tunix

Tunix is a small Unix-like operating system for x86_64, built from scratch: a custom bootloader, a custom kernel, and a userland assembled from ported free software. This site is the new home for development notes and progress reports.

Why build another OS?

Because reading about how an operating system works is not the same as building one. Every subsystem in Tunix — the VFS, the ext2 driver, the scheduler, the TCP stack, the DRM driver — exists because something above it needed it, and each one taught a lesson that no textbook chapter could.

The guiding constraint is simple: stay small enough to read. The kernel is on the order of twenty thousand lines of C. You can sit down with it in an afternoon.

Where things stand

Today Tunix boots from its own bootloader into a kernel with:

• A persistent ext2 root filesystem that Linux can mount too
• The Linux x86_64 syscall ABI, so musl-built binaries just run
• A TCP/IP stack good enough for git clone https://...
• A Wayland desktop: Weston on a native DRM driver, with GL rendering, keyboard and mouse input, and a real terminal emulator

And the userland is not a toy: bash, GNU coreutils, gcc, binutils, make, git, nano, htop, lua, and more, all built against musl. Tunix is self-hosting — it can compile programs for itself, on itself.

What's next

The current focus is the graphics stack: the virtio-gpu driver already does 2D KMS against a real virtual GPU, and the next milestone is the virgl 3D path for actual GPU-accelerated OpenGL.

If any of this sounds interesting, the code is on GitHub — and this blog accepts posts by pull request.