Building Managarm

This guide shows how to build a managarm distribution from source utilising the bootstrap-managarm patches and build scripts.

Building a managarm distribution from source

Build environment

To make sure that all build environments work properly, it is recommended to setup a build environment with our lightweight containerized build runtime cbuildrt (see below for instructions). It is also possible to build with Docker (see here), or by installing the dependencies manually (see here), but these methods are no longer recommended.

Make sure that you have at least 20 - 30 GiB of free disk space.


  1. Create a directory which will be used for storing the source and build directories. Here we use ~/managarm, but it can be any directory.
    mkdir ~/managarm && cd ~/managarm
  2. Install the xbstrap build system via pip3:
    pip3 install xbstrap
  3. The git, subversion and mercurial tools are required on the host (whether you build in a container or not). Install these via your package manager.
  4. Clone this repository into a src directory and create a build directory:
    git clone src
    mkdir build

Creating a cbuildrt environment

  1. Download and install the latest cbuildrt release by running:

    xbstrap prereqs cbuildrt xbps

    Note: If you choose to build cbuildrt from source, make sure to place the resulting binary either in $PATH or in ~/.xbstrap/bin.

  2. Download and unpack the latest Managarm rootfs somewhere:

    curl -o managarm-rootfs.tar.gz
    tar xvf managarm-rootfs.tar.gz
  3. Inside the build directory, create a file named bootstrap-site.yml with the following contents (replace the container.rootfs key as appropriate):

      format: xbps
      runtime: cbuildrt
      rootfs:  /path/to/your/rootfs
      uid: 1000
      gid: 1000
      src_mount: /var/lib/managarm-buildenv/src
      build_mount: /var/lib/managarm-buildenv/build
      allow_containerless: true

    Note: you must keep the src_mount and build_mount values as shown above if you want to be able to use pre-built tools from our build server. These paths refer to locations on the container, not on your host machine. Also note that these paths cannot be changed after starting the build; doing so will likely result in a broken directory tree.


  1. Initialize the build directory with

    cd build
    xbstrap init ../src
  2. There are several meta-packages available which control what software is built, this means that the build can be started using one of the following commands:

    If you want the full managarm experience with a selection of terminal and gui software available to try out use

    xbstrap install weston-desktop

    If you want to boot into kmscon and have some functional commands to play around with use

    xbstrap install base

    If you want some development tools in addition to the functionality of base use

    xbstrap install base-devel

    If you only want to build the bare minimum to boot into kmscon use

    xbstrap install --all

    Note that this command can take multiple hours, depending on your machine.

Creating Images

Note: if using a Docker container the following command are meant to be ran outside the Docker container, in the build directory on the host. Adding to the aforementioned commands, one would exit from the container once the build finishes, enter the build directory, and proceed as follows.

After managarm's packages have been built, building a HDD image of the system is straightforward. The script can be used to create an empty HDD image.

Download the script and mark it executable:

wget ''
chmod +x

This repository contains an script to mount the image and copy the system onto it.

This script can use 3 different methods to copy files onto the image:

  1. Using libguestfs (the default method). We recommend this when root access is not possible or desirable. However, it is much slower than method 2 and requires some setup on the host (see below).
  2. Using a classic loopback and mount (requires root privileges). We recommend this when root access is acceptable because it is the fastest method and most guaranteed to work.
  3. Via Docker container (only works with the Docker build method). This is handy in case the user is in the docker group since it does not require additional root authentication. We discourage this because it uses docker run --privileged (which is not safer than giving root access) and currently has some bugs.

Going with method 1 will require libguestfs to be installed on the host. After installing libguestfs it might be necessary to run the following:

sudo install -d /usr/lib/guestfs
sudo update-libguestfs-appliance

If you're using xbstrap to invoke the script, selecting the desired method can be done by adding the following to the bootstrap-site.yml file:

    mount-using: 'loopback' # or guestfs/docker

When invoking the script directly, selecting the method can be done with the --mount-using argument.

For all methods, the and make-image invocations shown below require the following programs to be installed: rsync, losetup, sfdisk, mkfs.ext2, mkfs.vfat. Refer to image_create for more details on this.

Hence, running the following commands in the build directory should produce a working image and launch it using QEMU:

# Create a HDD image file called 'image'.
# Check "./ -h" for more options.
./ -o image -s 4GiB -t ext2 -p gpt -l limine -be

# Copy the system onto it.
xbstrap run make-image

# Launch the image using QEMU.
xbstrap run qemu

# Or as a one-liner:
xbstrap run make-image qemu

# Alternatively, you can call the necessary scripts manually:
# Check their help messages for more information.
../src/scripts/ qemu