GuardBSD
Rust Multi-Microkernel OS • Capability Security • Production-Ready
GuardBSD Documentation
Overview & Quick Start
High-level picture of the Winter Saga release, key components, and how to get started fast.
Overview
GuardBSD is a multi-microkernel operating system in Rust with capability-based security, TCB < 8,000 lines, a full storage stack, and a 100% BSD-licensed bootloader.
Winter Saga — first production-ready release
- GuaBoot: 100% BSD bootloader (BIOS + UEFI), <1 second, ~60 KB
- gsh: zsh-level shell (scripting, job control, tab completion)
- GuardFS + GuardZFS: native FS + ZFS features in 1,543 lines
- 23 partition types, swap, ATA, block cache
- API Reference and Architecture Docs — fully documented
Key Features
| Component | Status | Description |
|---|---|---|
| GuaBoot | Production-Ready | 100% BSD, BIOS/UEFI, ELF64, FreeBSD protocol, ~2,650 LOC |
| gsh Shell | Production-Ready | zsh-level: history, job control, scripts, aliases, functions |
| GuardZFS | Production-Ready | Pools, RAID-Z1/Z2, COW, snapshots, SHA-256, 1,543 LOC |
| GuardFS | Production-Ready | Journaling, snapshots, LZ4, COW, ~3,200 LOC |
| Disk I/O | Production-Ready | ATA, cache (128 blocks), 23 partition types, swap |
| Swap | Production-Ready | Auto-detection, up to 4, swapon/swapoff |
| Three Microkernels | FOSDEM 2026 | µK-Time, µK-Space, µK-IPC — source closed until premiere |
Microkernels are not public — world premiere at FOSDEM 2026.
Quick Start
# Clone
git clone https://github.com/Cartesian-School/guardbsd
cd guardbsd
# Build ISO
make iso
# Run
qemu-system-x86_64 -cdrom build/x86_64/guardbsd-winter-saga.iso -m 2G -smp 4 -serial stdio