BoredOS is a from-scratch x86-64 UNIX-like hobby operating system written in C.
It implements preemptive scheduling, demand-paged virtual memory with COW, an ext4/FAT32-capable VFS, Unix domain sockets, a custom init system (YAWN), and hardware drivers spanning AHCI, AC97 audio, and common network cards (e1000, RTL8139/8111, VirtIO). It targets a practical subset of POSIX, enough to run standard userspace tools and dynamic ports via mlibc. The design aims for a clean, modern UNIX rather than decades of accumulated backwards-compatibility bloat.
bpm is our package manager. It installs, removes, and upgrades software from a remote repository index. Packages are .bup files, which are really just tar archives compressed with LZ4, plus a TOML manifest and optional install/remove hook scripts.
There's a community repo, BUR, where anyone can submit packages through a pull request. If you want to add something, the packaging guide walks through the format.
Nova is a custom compositor built for BoredOS, with its own UI toolkit and a win9x-inspired design language.
YAWN (Yet Another Workload Navigator) is our custom init and service management system. It bootstraps userspace, supervises login terminals, handles zombie process reaping, and manages daemons through a BSD-style rc system (/etc/rc.d and /etc/rc.conf). (YAWN also stands for "You Awake? Well, Now what?")
| Port | Notes |
|---|---|
| DOOM (doomgeneric) | What's an operating system without DOOM? |
| TinyGL | A software-rendered subset of OpenGL. |
| TCC | A small, fast C compiler. |
| Lua | Available as a shell tool or embeddable in other programs. |
| mlibc | The managarm C standard library. |
| kilo | A simple text editor. |
| kirc | A simple IRC client. |
| tvi | A vi-like text editor. |
| Subsystem | Details |
|---|---|
| SMP | Multi-core support via LAPIC. Per-CPU state lives in the GS segment. XSAVE/XRSTOR handle FPU context across switches. |
| Scheduler | Preemptive round-robin over a circular process list, with sleep/wake support, per-CPU affinity, and cross-core IPI for AP scheduling. |
| Memory | Physical page allocator (PMM), slab allocator, 4-level MMU with COW, VMA tracking with an RB-tree, demand paging, and a page cache. |
| VFS | Virtual filesystem layer supporting tmpfs, FAT32, ext4, ProcFS, DevFS, and SysFS. |
| IPC | Unix domain sockets, shared memory through /dev/shm, wait queues, and work queues. |
| PTY | Full pseudo-terminal support. |
| Devices | PCI, AHCI (SATA), PS/2, ACPI, I2C, AC97 audio, and RTC. |
| TTYs | 10 virtual terminals, each with its own graphics buffer. |
| ELF | Loads and runs ELF64 binaries with correct segment mapping. |
| Networking | LWIP TCP/IP stack with support for Intel e1000, RTL8139/RTL8111, and VirtIO-net. |
| Guide | Description |
|---|---|
| Documentation Index | Start here if you're new. |
| Architecture Overview | A deeper look at how the kernel is put together. |
| Building and Running | Get a build environment set up. |
| AppDev SDK | Write your own apps for BoredOS. |
| Packaging Guide | Package software for bpm. |
BoredOS is developed and maintained by a small group of contributors in their spare time, independent of any company or organization. Development isn't tied to funding, but if you find the project useful or interesting, a donation is welcome and goes toward continued development.
Distributed under the GNU General Public License v3. See LICENSE for the full text.
Important
Keep all copyright headers intact and include the original attribution in any redistribution or derivative work. Details are in the NOTICE file.
BoredOS grew out of BrewKernel, a project Christiaan started back in 2023. BrewKernel is archived now and will no longer be updated.