TwanOS_

Active

A lightweight separation kernel designed for adaptability, real-time computing, and mixed-criticality workloads. Built from scratch by a 332 member.

What it is_

Twan is intended to serve as foundational infrastructure for building specialized systems — not a complete end-user environment. It is designed to be adapted and extended for specific deployment requirements.

It is currently in early-stage development with support for Intel processors with VT-x, EPTs, and unrestricted guest mode. Twan is not currently ARINC 653 or SKPP compliant out of the box — certification requires formal verification and safety analysis beyond the current scope.

Twanvisor

A hypervisor that leverages hardware-assisted virtualisation to isolate partitions. Guests are paravirtualised and use APIs provided by Twanvisor.

TwanRTOS

The trusted root partition operating system that acts as the system orchestrator. Initializes Twanvisor, controls partition policies, and serves as the central manager for hardware and system resources.

Requirements_

Currently supports Intel processors with:

VT-x

Intel Virtualization Technology for IA-32, Intel 64 and Intel Architecture

EPTs

Extended Page Tables — second-level address translation for guests

Unrestricted Guest

Supports real-mode and big real-mode guest execution

Note: Even if your hardware meets these requirements, it may not work out of the box. The project is in early development.

Adaptability

Designed to be adapted and extended for specific deployment requirements — not a fixed monolithic system.

Real-Time

Built for real-time computing — deterministic execution, predictable timing, suitable for time-critical workloads.

Mixed-Criticality

Supports mixed-criticality systems — isolating high-criticality tasks from lower-criticality ones within the same hardware.

Separation

Enforces strong separation between partitions — hardware-level isolation via virtualisation technology.

Lightweight

Minimal footprint by design — kernel code in C and assembly, focused on doing the separation job and nothing more.

Open Source

Licensed under MIT. Source on GitHub. Contributions welcome — see the repo for current status.

Stack & Dependencies_

C (97.7%)Assembly (1.8%)uACPInanoprintfConcurrency KitGRUBKconfigMIT License

References: Muen, L4re/Fiasco, Composite, cmrx, Nova, Xen, POK, XtratuM, Deos, EURO-MILS MILS Architecture Whitepaper, Separation Kernel Protection Profile.

Development_

Twan is in early development. It is not production-ready. If you want to follow along, track issues, or contribute, the GitHub repository is the right place.