Host Dependencies

This page describes how to set up your host machine to build and run seL4 and its supported projects. To compile and use seL4 you can either:

  • Recommended: Use Docker to isolate the dependencies from your machine. Detailed instructions for using Docker for building seL4, Camkes, and L4v can be found here.
  • Install the following dependencies on your local OS

The following instructions describe how to set up the required dependencies on your local OS. This page assumes you are building in a Linux OS. We however encourage site contributions for building in alternative OSes (e.g. macOS).

Get Google’s Repo tool

The primary way of obtaining and managing seL4 project source is through the use of Google’s repo tool. To get repo, follow the instructions described in the section “Installing Repo” here.

See the RepoCheatsheet page for a quick explanation of how we use Repo.

seL4 Build Dependencies

To build seL4-based projects, ensure you have installed the dependencies described in the Base Build Dependencies and Python Dependencies sections below.

Base Build Dependencies

To establish a usable development environment it is important to install your distributions basic build packages.

Ubuntu

These instructions are intended for Ubuntu LTS versions 20.04 and 22.04.

As dependencies and packages may be frequently changed, deprecated or updated these instructions may become out of date. If you discover any missing dependencies and packages we welcome new contributions to the page.

Base dependencies

The basic build package on Ubuntu is the build-essential package. To install run:

sudo apt-get update
sudo apt-get install build-essential

Additional base dependencies for building seL4 projects on Ubuntu include installing:

sudo apt-get install cmake ccache ninja-build cmake-curses-gui
sudo apt-get install libxml2-utils ncurses-dev
sudo apt-get install curl git doxygen device-tree-compiler
sudo apt-get install u-boot-tools
sudo apt-get install python3-dev python3-pip python-is-python3
sudo apt-get install protobuf-compiler python3-protobuf

Simulating with QEMU

In order to run seL4 projects on a simulator you will need QEMU:

sudo apt-get install qemu-system-arm qemu-system-x86 qemu-system-misc

Cross-compiling for ARM targets

To build for ARM targets you will need a cross compiler:

sudo apt-get install gcc-arm-linux-gnueabi g++-arm-linux-gnueabi
sudo apt-get install gcc-aarch64-linux-gnu g++-aarch64-linux-gnu

(you can install the hardware floating point versions as well if you wish)

sudo apt-get install gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf

Cross-compiling for RISC-V targets

To build for RISC-V targets you will need a cross compiler:

  1. It is recommended to build the toolchain from source.

     git clone https://github.com/riscv/riscv-gnu-toolchain.git
 cd riscv-gnu-toolchain
 git submodule update --init --recursive
 export RISCV=/opt/riscv
 ./configure --prefix="${RISCV}" --enable-multilib
 make linux

    After it is built, add the $RISCV/bin folder to your PATH. The built toolchain works for both 32-bit and 64-bit.

  2. Alternatively, any pre-built toolchain with multilib enabled should work.

Builidng the seL4 manual

If you would like to build the seL4 manual, you will need the following LaTeX pacakges:

sudo apt-get install texlive texlive-latex-extra texlive-fonts-extra

Debian

For Debian Stretch or later

The dependencies listed in our docker files repository will work for a Debian installation. You can refer to this repository for an up-to-date list of base build dependencies. Specifically refer to the dependencies listed in the:

The version of cmake in Debian stretch is too old to build seL4 projects (buster and later are OK). If you are on stretch, install cmake from stretch-backports:

Add the stretch-backports repository like this (substitute a local mirror for ftp.debian.org if you like)

sudo sh -c "echo 'deb http://ftp.debian.org/debian stretch-backports main' > /etc/apt/sources.list.d/backports.list"

Then install cmake with

sudo apt-get update
sudo apt-get -t stretch-backports install cmake

Python Dependencies

Regardless of your Linux distribution, python dependencies are required to build seL4, the manual and its proofs. To install you can run:

pip3 install --user setuptools
pip3 install --user sel4-deps

(Some distributions use pip for python3, others use pip3. Use the Python 3 version for your distribution)

CAmkES Build Dependencies

To build a CAmkES based project on seL4, additional dependencies need to be installed on your host machine. Projects using CAmkES (the seL4 component system) need Haskell and some extra Python libraries in addition to the standard build tools. The following instructions cover the CAmkES build dependencies for Ubuntu/Debian. Please ensure you have installed the dependencies listed in sections seL4 Build Dependencies and Get Google’s Repo tool prior to building a CAmkES project.

Python Dependencies

The Python dependencies required by the CAmkES build toolchain can be installed via pip:

pip3 install --user camkes-deps

Haskell Dependencies

The CAmkES build toolchain additionally requires Haskell. You can install the Haskell stack on your distribution by running:

curl -sSL https://get.haskellstack.org/ | sh

If you prefer not to bypass your distribution’s package manager, you can do

sudo apt-get install haskell-stack

Build Dependencies

Ubuntu

These instructions are intended for Ubuntu LTS versions 20.04 and 22.04.

Install the following packages:

sudo apt-get install clang gdb
sudo apt-get install libssl-dev libclang-dev libcunit1-dev libsqlite3-dev
sudo apt-get install qemu-kvm

Debian

For Debian Stretch or later

The dependencies listed in our docker files repository will work for a Debian installation. You can refer to this repository for an up-to-date list of base build dependencies. Specifically refer to the dependencies listed in the:

Proof and Isabelle Dependencies

Proof Dependencies

Linux Packages - Debian

On Buster or Bullseye, to run all proofs against the ARMv7-A architecture you will need to install the following packages:

sudo apt-get install \
    python3 python3-pip python3-dev \
    gcc-arm-none-eabi build-essential libxml2-utils ccache \
    ncurses-dev librsvg2-bin device-tree-compiler cmake \
    ninja-build curl zlib1g-dev texlive-fonts-recommended \
    texlive-latex-extra texlive-metapost texlive-bibtex-extra \
    rsync

There is no package for the MLton compiler on Buster or Bullseye, so you will need to install it from the MLton website.

The Haskell Stack package is unavailable on Bullseye and out-of-date on Buster, so you will need to install it from the Haskell Stack website.

Continue with the python setup step below.

Linux Packages - Ubuntu

These instructions are intended for Ubuntu LTS versions 20.04, and 22.04.

To run all proofs against the ARMv7-A architecture you will need to install the following packages:

sudo apt-get install \
    python3 python3-pip python3-dev \
    gcc-arm-none-eabi build-essential libxml2-utils ccache \
    ncurses-dev librsvg2-bin device-tree-compiler cmake \
    ninja-build curl zlib1g-dev texlive-fonts-recommended \
    texlive-latex-extra texlive-metapost texlive-bibtex-extra \
    mlton-compiler haskell-stack repo

Continue with the python setup step below.

macOS packages

The proofs work well on Intel and Apple Silicon Macs.

These instructions use Homebrew, which can be installed from their website. To install the main dependencies and cross compilers, use the following steps:

brew install git libxml2 ncurses librsvg dtc cmake ninja texlive rsync python ccache \
     zstd haskell-stack mlton arm-none-eabi-gcc repo

brew install --cask gcc-arm-embedded

brew tap messense/macos-cross-toolchains
brew install x86_64-unknown-linux-gnu aarch64-unknown-linux-gnu

brew tap riscv/riscv
brew install riscv-tools

The instructions in the sections below apply for both Linux and macOS.

Python

The build system for the seL4 kernel requires several python packages:

pip3 install --user --upgrade pip
pip3 install --user sel4-deps

Haskell Stack

After installing haskell-stack (already included in the packages above on Mac and Ubuntu), make sure you’ve adjusted your PATH to include $HOME/.local/bin, that you’re running an up-to-date version, and that you have installed cabal:

stack upgrade --binary-only
which stack # should be $HOME/.local/bin/stack
stack install cabal-install

Checking out the repository collection

The seL4 repositories use the Google repo tool for configuration control and managing sets of repositories. For verification, this means in particular managing the correct combinations of the proofs, the kernel sources, and the Isabelle/HOL theorem prover.

The verification-manifest repository records which versions of these are known to work well together.

To check out a consistent set of repositories, run the following steps:

mkdir verification
cd verification
repo init -u https://git@github.com/seL4/verification-manifest.git
repo sync

If you are developing proofs, intending to contribute, and have ssh set up for GitHub, use

repo init -m devel.xml -u ssh://git@github.com/seL4/verification-manifest.git

instead for the init line. The -m devel.xml gives you the master branch of the l4v repository instead of the last known-good version. To set up git for ssh make sure to use the ssh:// protocol explicitly as above instead of just git@github.com, because the short form seems to confuse repo.

If you are looking to use the proofs for a specific release version of seL4, use the -m option to select the corresponding manifest file in the verification-manifest repository.

Isabelle Setup

After the repository is set up using repo with the verification-manifest repository, you should have following directory structure, where l4v is the repository you are currently looking at:

verification/
    HOL4/
    graph-refine/
    isabelle/
    l4v/
    seL4/

To set up Isabelle for use in l4v/, assuming you have no previous installation of Isabelle, run the following commands in the directory verification/l4v/:

mkdir -p ~/.isabelle/etc
cp -i misc/etc/settings ~/.isabelle/etc/settings
./isabelle/bin/isabelle components -a
./isabelle/bin/isabelle jedit -bf
./isabelle/bin/isabelle build -bv HOL

These commands perform the following steps:

  • create an Isabelle user settings directory.
  • install L4.verified Isabelle settings. These settings initialise the Isabelle installation to use the standard Isabelle contrib tools from the Munich Isabelle repository and set up paths such that multiple Isabelle repository installations can be used side by side without interfering with each other.
  • download contrib components from the Isabelle repository. This includes Scala, a Java JDK, PolyML, and multiple external provers. You should download these, even if you have these tools previously installed elsewhere to make sure you have the right versions. Depending on your internet connection, this may take some time.
  • compile and build the Isabelle PIDE jEdit interface.
  • build basic Isabelle images to ensure that the installation works. This may take a few minutes.

Alternatively, it is possible to use the official Isabelle2022 release bundle for your platform from the Isabelle website. In this case, the installation steps above can be skipped, and you would replace the directory verification/isabelle/ with a symbolic link to the Isabelle home directory of the release version. Note that this is not recommended for development, since Google repo will overwrite this link when you synchronise repositories and Isabelle upgrades will have to be performed manually as development progresses.

You are now set up to process proofs, for instance by following the instructions at the bottom of the main README page.

The sections below contain a few tools and tips for proof development on seL4.

PIDE Tools

The following tools and tips can make writing proofs easier and more efficient when using the Isabelle PIDE jEdit interface.

WhiteSpace plugin

The WhiteSpace plugin can highlight normally invisible whitespace characters such as tabs and spaces, and can remove trailing whitespace on save. To install and configure the WhiteSpace plug-in for jEdit, follow the instructions below.

  1. Go to Plugins -> Plugin manager -> Install.
  2. Search for WhiteSpace and install the plugin.
  3. Go to Plugins -> Plugin Options -> WhiteSpace -> On save actions.
  4. Check “Remove trailing whitespace” and click Apply.

Key bindings for Navigator

The Isabelle PIDE provides “Back” and “Forward” actions that allow you to easily navigate to previous positions in your edit history. Follow the steps below to bind a key to the “Back” function. We recommend [ctrl]+[`].

  1. Go to Utilities -> Global Options -> jEdit -> Shortcuts.
  2. Select Action Set -> Plugin: Navigator.
  3. Set a shortcut for Back.

Go-to-error macro

Run the following commands in the directory verification/l4v/:

mkdir -p ~/.isabelle/jedit/macros
cp misc/jedit/macros/goto-error.bsh ~/.isabelle/jedit/macros/.

You can add keybindings for this macro in the usual way, by going to Utilities -> Global Options -> jEdit -> Shortcuts.

Additionally, our fork of Isabelle/jEdit has an updated indenter which is more proof-context aware than the ‘original’ indenter. Pressing ctrl+i while some apply-script text is selected should auto-indent the script while respecting subgoal depth and maintaining the relative indentation of multi-line apply statements.