Skip to content

Theseus is a modern OS written from scratch in Rust that explores ๐ข๐ง๐ญ๐ซ๐š๐ฅ๐ข๐ง๐ ๐ฎ๐š๐ฅ ๐๐ž๐ฌ๐ข๐ ๐ง: closing the semantic gap between compiler and hardware by maximally leveraging the power of language safety and affine types. Theseus aims to shift OS responsibilities like resource management into the compiler.



Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time

Theseus OS

Documentation Book Blog Discord
Build Action Clippy Action QEMU tests

Theseus is a new OS written from scratch in Rust to experiment with novel OS structure, better state management, and how to leverage intralingual design principles to shift OS responsibilities like resource management into the compiler.

For more info, check out Theseus's documentation or our published academic papers, which describe Theseus's design and implementation.

Theseus is under active development, and although it is not yet mature, we envision that Theseus will be useful in high-end embedded systems or edge datacenter environments. We are continually working to improve the OS, including its fault recovery abilities for higher system availability without redundancy, as well as easier and more arbitrary live evolution and runtime flexibility.

Quick start

On Linux (Debian-like distros), do the following:

  1. Obtain the Theseus repository (with all submodules):
    git clone --recurse-submodules --depth 1
  2. Install Rust:
    curl -sSf | sh
  3. Install dependencies:
    sudo apt-get install make gcc nasm pkg-config grub-pc-bin mtools xorriso qemu qemu-kvm wget
  4. Build and run (in QEMU):
    cd Theseus
    make run
    To exit QEMU, press Ctrl + A, then X.

See below for more detailed instructions.

Building and Running Theseus

Note: when you first check out the project, be sure to get all the submodule repositories too:

git submodule update --init --recursive

Currently, we support building Theseus on the following platforms:

  • Linux, 64-bit Debian-based distributions like Ubuntu, tested on Ubuntu 16.04, 18.04, 20.04.
    • Arch Linux and Fedora have also been reported to work correctly.
  • Windows, using the Windows Subsystem for Linux (WSL), tested on the Ubuntu version of WSL and WSL2.
  • MacOS, tested on versions High Sierra (v10.13), Catalina (v10.15), and Ventura (v13.5).
  • Docker, atop any host OS that can run a Docker container.

Setting up the build environment

First, install Rust by following the setup instructions here. On Linux, just run:

curl -sSf | sh

Building on Linux or WSL (Windows Subsystem for Linux)

Install the following dependencies using your package manager:

sudo apt-get install make gcc nasm pkg-config grub-pc-bin mtools xorriso qemu qemu-kvm wget
  • Or:
    # Arch Linux
    sudo pacman -S make gcc nasm pkg-config grub mtools xorriso qemu wget
    # Fedora
    sudo dnf install make gcc nasm pkg-config grub2 mtools xorriso qemu wget

If you're on WSL, also do the following steps:

  • Install an X Server for Windows; we suggest using Xming or VcXsvr.

    • You'll likely need to invoke those X servers with the -ac argument (or use the GUI to disable access control).
  • Setup an X display as follows:

    • on original WSL (version 1), run:
      export DISPLAY=:0
    • on WSL2 (version 2), run:
      export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2}'):0

    You'll need to do this each time you open up a new WSL terminal, so it's best to add it to the end of your .bashrc or .profile file in your $HOME directory.

  • If you get an error like Could not initialize SDL (No available video device) ... or any type of GTK or video device error, then make sure that your X Server is running and that you have set the DISPLAY environment variable above.

  • NOTE: WSL and WSL2 do not currently support using KVM.

Building on MacOS

  • Install HomeBrew, then run the MacOS build setup script:

    sh ./scripts/

    If things go wrong, remove the following build directories and try to run the script again.

    rm -rf /tmp/theseus_tools_src
  • NOTE: on MacOS, you need to run gmake instead of make for build commands (or you can simply create a shell alias).

    • This is because HomeBrew installs its binaries in a way that doesn't conflict with built-in versions of system utilities.
  • (This is typically not necessary): if you're building Theseus on older Apple Silicon (M1 chips), you may need to use bash with x86 emulation:

    arch -x86_64 bash   # or another shell of your choice

    and possibly adjust your system PATH if both x86 and ARM homebrew binaries are installed:

    export PATH=/usr/local/Homebrew/bin:$PATH

Building using Docker

Note: building and running Theseus within a Docker container may be slower than on a native host OS.

  1. Ensure docker scripts are executable:

    chmod +x docker/*.sh
  2. (Skip if docker is already installed.) Install Docker Engine. We provide a convenience script for this on Ubuntu:

    • After docker installs, enable your user account to run docker without root privileges:
      sudo groupadd docker; sudo usermod -aG docker $USER
      Then, log out and log back in (or restart your computer) for the user/group changes to take effect.
  3. Build the docker image:


    This does not build Theseus, but rather only creates a docker image that contains all the necessary dependencies to build and run Theseus.

  4. Run the new docker image locally as a container:


    Now you can run make run or other Theseus-specific build/run commands from within the docker container's shell.

Notes on Docker usage:

  • The docker-based workflow should only require you to re-run the script multiple times when re-building or running Theseus after modifying its code. You shouldn't need to re-run multiple times, though it won't hurt.
  • KVM doesn't currently work in docker. To run Theseus in QEMU using KVM, you can build Theseus within docker, exit the container (via Ctrl + D), and then run make orun host=yes` on your host machine.

Building and Running

Build the default Theseus OS image and run it in QEMU:

make run

Or, build a full Theseus OS image with all features and crates enabled:

make full   ## or `make all`

Run make help to see other make targets and the various command-line options.

Using the Limine bootloader instead of GRUB

To use Limine instead of GRUB, clone pre-built limine and pass bootloader=limine to make:

git clone limine-prebuilt
git -C limine-prebuilt reset --hard 3f6a330
make run bootloader=limine

Feel free to try newer versions, however they may not work.

Targeting ARMv8 (aarch64)

Support for Theseus on aarch64 is an ongoing effort, but most of the core subsystems are complete.

To build and run Theseus on aarch64, first install the required dependencies:

  • On Debian-like Linux (Ubuntu, etc):
    sudo apt-get install qemu-system-arm gcc-aarch64-linux-gnu
  • On Arch Linux:
    sudo pacman -S aarch64-linux-gnu-gcc qemu-system-aarch64
  • On macOS, the mac_os_build_setup script should have already installed this for you, but if not:
    brew install aarch64-elf-gcc aarch64-elf-binutils

Then, build Theseus and run it in QEMU:

make ARCH=aarch64 run

Doing a "full" build of all Theseus crates isn't yet supported on aarch64, as our aarch64 support in Theseus doesn't yet cover all crates in the entire repo.

Using QEMU

QEMU allows us to run Theseus quickly and easily in its own virtual machine. To release your keyboard and mouse focus from the QEMU window, press Ctrl + Alt + G, or Ctrl + Alt on some systems, or just Cmd + Tab out to another app on macOS. To exit QEMU, in the terminal window that you originally ran make run, press Ctrl + A then X, or you can also click the GUI โ“ง button on the title bar if running QEMU in graphical mode.

To investigate the hardware/machine state of the running QEMU VM, you can switch to the QEMU console by pressing Ctrl + Alt + 2. Switch back to the main window with Ctrl + Alt + 1. On Mac, manually select VGA or compact_monitor0 under View from the QEMU menu bar.

To access/expose a PCI device in QEMU using PCI passthrough via VFIO, see these instructions.

Linux does not support the ICMP protocol (for ping) for guest OSes in QEMU by default, so to allow ping to work on Theseus, you may need to run the following in your Linux host machine:

sudo sh -c "echo \"0 2147483647\" > /proc/sys/net/ipv4/ping_group_range"

KVM Support

While not strictly required, KVM will speed up the execution of QEMU. To install KVM, run the following command:

sudo apt-get install kvm

To enable KVM support, add host=yes to your make command, e.g.,

make run host=yes

Note that KVM acceleration is only supported on native Linux hosts.


Theseus includes two forms of documentation:

  1. The source-level documentation, generated from code and inline comments (via rustdoc).
    • Intended for Theseus developers and contributors, or those who want low-level details.
  2. The book-style documentation, written in Markdown.
    • Useful for high-level descriptions of design concepts and key components.

To build the documentation yourself, set up your local build environment and then run the following:

make view-doc   ## for the source-level docs
make view-book  ## for the Theseus book


Booting on Real Hardware

We have tested Theseus on a variety of real machines, including Intel NUC devices, various Thinkpad laptops, and Supermicro servers. Currently, we have only tested booting Theseus via USB or PXE using a traditional BIOS bootloader rather than UEFI, but UEFI is fully supported so it should work.

To boot over USB, simply run make usb drive=sdc, in which sdc is the device node for the USB disk itself (not a partition like sdc2) to which you want to write the OS image. On WSL or other host environments where /dev device nodes don't exist, you can simply run make iso and burn the .iso file in the build/ directory to a USB, e.g., using Rufus on Windows.

To boot Theseus over PXE (network boot), see this set of separate instructions.

Debugging Theseus on QEMU

GDB has built-in support for QEMU, but it doesn't play nicely with OSes that run in 64-bit long mode. In order to get it working properly with our OS in Rust, we need to patch it and build it locally. The hard part has already been done for us (details here), so we can just quickly set it up with the following commands.

  1. Install the following packages:

    sudo apt-get install texinfo flex bison python-dev ncurses-dev
  2. From the base Theseus directory, run this script to download and build GDB from an existing patched repo:

    curl -sf | sh

    After that, you should have a rust-os-gdb directory that contains the gdb executables and scripts.

  3. Run Theseus in QEMU using make run (or make run_pause to pause QEMU until we attach GDB).

  4. In another terminal window, run the following to start GDB and attach it to the running QEMU instance:

    make gdb 

    QEMU will be paused until we move the debugger forward, with standard GDB commands like n to step through the next instruction or c to continue execution. Any standard GDB commands will now work.

Connecting GDB to aarch64 Theseus on QEMU

We don't yet have a patched version of GDB for aarch64 targets, but we can use the existing gdb-multiarch package to

  1. Install the required package:

    sudo apt-get install gdb-multiarch
  2. Build Theseus for aarch64 and run it in QEMU:

    make ARCH=aarch64 run ## or use `run_pause`
  3. In another terminal window, run the following to start GDB and attach it to the running QEMU instance:

    gdb-multiarch -ex "target remote :1234"
  4. Within GDB, symbols aren't yet supported, but you can view assembly code with layout asm and set breakpoints on virtual addresses.

IDE Setup

Our personal preference is to use VS Code, which has excellent cross-platform support for Rust. Other options are available here.

For VS Code, recommended plugins are:

  • rust-analyzer, by matklad
  • Better TOML, by bungcip
  • x86 and x86_64 Assembly, by 13xforever


We would like to express our thanks to the OS Dev wiki and its community and to Philipp Oppermann's blog_os for serving as excellent starting points for Theseus. The early days of Theseus's development progress are indebted to these resources.


Theseus's source code is licensed under the MIT License. See the LICENSE-MIT file for more.


We adhere to similar development and code style guidelines as the core Rust language project. See more here.

PRs and issues are welcome from anyone; because Theseus is an experimental OS, certain features may be deprioritized or excluded from the main branch. Don't hesitate to ask or mention something though! ๐Ÿ˜„


Theseus is a modern OS written from scratch in Rust that explores ๐ข๐ง๐ญ๐ซ๐š๐ฅ๐ข๐ง๐ ๐ฎ๐š๐ฅ ๐๐ž๐ฌ๐ข๐ ๐ง: closing the semantic gap between compiler and hardware by maximally leveraging the power of language safety and affine types. Theseus aims to shift OS responsibilities like resource management into the compiler.







Sponsor this project