Welcome to the GenOS Home Page!

GenOS is a free operating system for x86_64 PCs, written from scratch in Rust. An operating system is the software that starts your machine and lets programs use its hardware. Ours already boots and runs a text shell: you type a command, and it answers.

We are building our own UEFI loader and kernel, the central part of the system. Programs run in Ring 3, with their own memory spaces. For now, the shell uses a serial terminal rather than a graphical desktop.

GenOS is an independent project with its own loader, kernel, shell, storage and network code. It is not a Linux distribution and does not use the Linux kernel. Have a look around, read the notes, or try a build in QEMU.

New here? Start here

Meet GenOS — short answers about the project and its limits.
Try it in QEMU — tools, commands and what to expect.
See what works so far — progress, with the unfinished bits included.
Look up an unfamiliar word — our plain-English glossary.

A word of warning

Experimental / ALPHA software — use at your own risk! GenOS is still under heavy development. This preview is for learning and controlled VM experiments. Do not use it for production, daily use, important data, secrets or hostile workloads.

GenOS at a glance — the current development tree
Architecture	64-bit x86 PCs, UEFI boot, one active kernel CPU
Interface	Text commands through a serial terminal; graphics postponed
VM for testing	QEMU, 512 MiB RAM; exact reference VM settings (not yet fully qualified)
Next goal	R1: verified kernel reference — still open
License	MIT

The kernel can give running programs turns on the CPU. It also has working parts for saving files and talking to a virtual network card. Programs ask for access through capabilities, handles that describe what they may use. These parts still have strict limits and need more testing together. Please read the known limitations and roadmap before trying the system.

A peek at the console

Captured GenOS boot log: storage initializes, serial terminal starts, and NORMAL_SHELL_READY is followed by the genos prompt — Serial console output from a real QEMU boot, rendered as an image. This excerpt ends at the normal shell prompt. View full size or read the full text log. Networking was restricted for this capture; the full log includes a DHCP failure. One boot does not establish release readiness.

For now, this text terminal is where the action is. See Build & Run for the commands and a picture of the loader that starts it.

What's New

Latest news from the development tree. These notes describe work in progress; they are not release announcements. Read the news archive.

[2026-10-21] — Changes in the development tree

We've been busy in the GenOS development tree with console workflows, selectable child quotas, TCP handling, and firmware memory-map checks. We're also reviewing resource ownership and keeping regression evidence, including deadline failures and remaining acceptance gaps. Please remember that GenOS is experimental ALPHA software, not for production work or important data.

[2026-10-20] — Changes in the development tree

We have 176 new commits in the GenOS development tree, with work on TCP reassembly and retransmission timing, CPU mappings, storage handling, and firmware exit paths. We’ve also been tending the test harnesses, retaining validation evidence, and clarifying the work still on our roadmap. As always, please remember that GenOS is experimental ALPHA software, not for production work or important data.

[2026-10-19] — Console, storage and network work; welcome to the home page!

We have added working directories and relative file paths managed by the kernel. The development tree also has offline backup and read-only restore for our GFS2 file system, plus a limited way to launch native utilities. Network work covers TCP replies that confirm only part of a transmission, and limited IPv6 UDP datagrams; integration and broader testing remain unfinished.

Welcome to the GenOS Home Page! We put the website online on 2026-10-19, with generated project status, news and commit history. GenOS is still Experimental / ALPHA.

[2026-10-18] — Reference VM notes: QEMU 11.1.2

We have updated the candidate reference VM — the exact virtual computer setup we aim to test — to QEMU 11.1.2. A follow-up commit records a full test-suite run for this updated v4 setup. We still need someone to reproduce the results independently, along with broader checks before we can call the setup qualified.

[2026-10-14] — From the development tree: console components and shell restart

We have added pieces for passing text between programs, including pipelines that let one program feed another, along with tests for starting and stopping those pieces. We also have code and test fixtures for leaving the guest shell and starting a new session. Connecting these parts into the running system and completing shutdown still need work.

Hacking on GenOS

Want to try it out or see how it works? These pages should help you get started.

Build and run GenOS — what you need and how to boot it in QEMU.
Read the documentation — design notes, current limits and test records.
Frequently Asked Questions (FAQ) — what works, what does not, and how to help.
Get the source — browse the GenOS tree on GitHub.

Send ordinary bug reports to the GitHub issue tracker. For private security reports, please follow SECURITY.md.