Tunix started in June as a bootloader that printed one line and then hung. Two months later it boots to a graphical login, opens an Xfce session, and lets you compile a C file with GCC inside a terminal that the kernel is drawing itself. I still find that funny.
It is written in C, with assembly only where there is nothing else to reach for, and the whole image is built by a Makefile. No Linux underneath. The boot path, the memory manager, the scheduler, the filesystem layer and the drivers are all in the repo.
Where it is now
The root filesystem is a real ext2 partition on the boot disk, so it survives
reboots and you can mount the image on Linux and poke around. The initramfs
only seeds it on the first boot. There is a proper mount table behind
mount and umount, with tmpfs, bind mounts and a /proc/mounts that reports
what actually happened.
The scheduler runs on every processor the firmware reports, not just the boot CPU. Getting the other cores up and then keeping the scheduler honest across them was the single hardest week of the project.
Userland is GNU. Coreutils, grep, sed, gawk, findutils, tar, gzip, make, Bash,
binutils and GCC are ported, along with nano and Lua. CPython 3.14 is built
shared, so ctypes and C extensions load, and the test script exercises
threads, subprocess, signals, sockets, epoll, mmap and sqlite3 to prove the
syscall layer is not lying.
Networking does both ends of TCP. bind, listen and accept work, connect
works, loopback is real, and the test runs a server and its client on the same
machine over 127.0.0.1. On top of that there is a static curl built against
mbedTLS, which gives curl https:// and git clone https:// from inside the
OS. SSH remotes are not supported yet.
Some other pieces that took longer than expected:
- Intel HD Audio playback behind ALSA's
/dev/snd, with alsa-lib ported on top - dinit as PID 1, with services under
/etc/dinit.danddinitctlto poke them - Real users: per process credentials, permission checks, setuid binaries,
login,su,passwdandsudo - Eight virtual terminals on Ctrl+Alt+F1 through F8, each with its own screen and keyboard state
- LightDM with the GTK greeter, authenticating through Linux PAM
- xbps as the package manager, installing from Tunix's own binary repository
- A virtio-gpu driver, so the display is scanned out where it already lives instead of being copied every frame
Running it
git submodule update --init --recursive
make all
make run
make headless if you would rather not have a QEMU window, make run-gpu for
the virtio-gpu path. The image ships with root / root and tunix / tunix.
What is next
Better hardware coverage, more of the userland ported, and a lot of cleanup in places where I clearly did not know what I was doing yet. The docs folder in the repo goes deeper on mounting, networking, SMP and the display manager.