Introduction

Introduction

Proton is a tool for use with the Steam client which allows games which are exclusive to Windows to run on the Linux operating system. It uses Wine to facilitate this.

Most users will prefer to use Proton provided by the Steam client itself. The source code is provided to enable advanced users the ability to alter Proton. For example, some users may wish to use a different version of Wine with a particular title.

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Getting Started with Proton from Steam Play

• As the new Steam Play is still in Beta, it is recommended that you opt into the Steam Client Beta for the latest features and fixes.
• Proton requires graphics drivers that are more recent than what is typically packaged in most distributions; please read the list of requirements and quickstart for Ubuntu 18.04 users
• Install and play games! Please refer to this post for more information.

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Obtaining Proton from source

NOTE: If you are not comfortable in a command line terminal, or if you find any of the information presented in here strange and uncomfortable, then this is probably not for you. The instructions are likely to be incomplete and require some knowledge and skill on your part, and there is no warranty or guarantee that anyone will help you with this process.

We strongly recommend that most users use the production build of Proton.

The most current source for Proton is here: https://github.com/ValveSoftware/Proton

Which you can clone to your system with this command:

   git clone https://github.com/ValveSoftware/Proton.git proton

After cloning the Proton git repository, the next step will be to obtain the various submodules that go into building Proton:

    cd proton
    git submodule update --init

If you wish to change any subcomponent, now is the time to do so. For example, if you wish make changes to Wine, you would apply those changes to the wine/ directory.

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Building

The following instructions describe how we create the build environment for the production builds of Proton. For reproducibility and security reasons, we build inside of a Debian 9 virtual machine. However, you should be able to follow these instructions on other distributions as well.

The Steam Runtime provides a clean and consistent set of libraries. Software distributed through Steam should depend only on libraries available through the runtime, and so we build in that environment for production Proton builds. However, if you are simply making a build for yourself, you can skip the Docker and Steam Runtime setup steps below, as they take a very long time to set up. At configure-time, pass the --no-steam-runtime flag instead of the Docker flags shown here.

The build system uses Docker containers. It requires your user to be able to usefully run Docker containers, which generally means your user needs to be in the "docker" group, which can have security implications.

Starting from a stock Debian 9 installation, you will need to install the gpgv2, gnupg2, g++, and g++-6-multilib packages from the Debian repos. You will also need to install meson version 0.43 or later, which can be acquired from backports. Next, install Docker-CE from the official Docker repositories. Finally, since we will need to be able to run Wine during the build process, install the winehq-devel package from the official WineHQ repositories. This will pull in all of the dependencies required to run wine. You can then (and we do) uninstall the winehq-devel package in order to ensure that a system Wine installation does not interfere with your build process.

Next we set up the Steam runtime build environments. Here we use the wip-docker branch to get access to the Docker images.

    cd ~
    git clone https://github.com/ValveSoftware/steam-runtime.git
    cd steam-runtime
    git checkout -b wip-docker origin/wip-docker

The steps below will build the Docker images. Each step will take a significant amount of time. Note the path to a file in the proton directory. See the previous section for instructions on cloning Proton.

    cd ~
    #set up the 64-bit Docker image for building Proton
    ./steam-runtime/setup_docker.sh --beta amd64 --extra-bootstrap=./proton/steamrt-bootstrap.sh steam-proton-dev
    #set up the 32-bit Docker image for building Proton
    ./steam-runtime/setup_docker.sh --beta i386 --extra-bootstrap=./proton/steamrt-bootstrap.sh steam-proton-dev32

With the build system set up, we can configure Proton and kick off the build. If you are not building in the runtime, pass --no-steam-runtime to configure.sh instead.

    mkdir proton/mybuild/
    cd proton/mybuild
    ../configure.sh --steam-runtime64=docker:steam-proton-dev --steam-runtime32=docker:steam-proton-dev32
    make -j6 all dist

Tip: If you are building without the Steam runtime as shown here, you should first run make obj-wine64/Makefile obj-wine32/Makefile and check the files obj-wine64/config.log and obj-wine32/config.log for missing packages. Search for won't be supported. A couple of missing packages are normal: opencv, gstreamer, vkd3d, oss, and libavcodec. More than that may indicate a problem. One easy way to install the dependencies required to build Wine is to use apt-get's build-dep feature.

The mybuild/dist folder now contains a build of Proton which you can install manually or with make install to install into your user's Steam installation. See the next section for more details.

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Deploying

Steam ships with several versions of Proton, which games will use by default or that you can select in Steam Settings's SteamPlay page. Steam also supports running games with local builds of Proton, which you can install on your machine.

To install a local build of Proton into Steam, make a new directory in ~/.steam/steam/compatibilitytools.d/ with a tool name of your choosing and place the contents of dist into that folder. The make install target will perform this task for you, installing the Proton build into the Steam folder for the current user. You will have to restart the Steam client for it to pick up on a new tool.

A correct local tool installation should look like this:

    compatibilitytools.d/my_proton/
    ├── compatibilitytool.vdf
    ├── filelock.py
    ├── LICENSE
    ├── proton
    ├── proton_dist.tar.gz
    ├── toolmanifest.vdf
    ├── user_settings.sample.py
    └── version

Each component of this software is used under the terms of their licenses. See the LICENSE files here, as well as the LICENSE, COPYING, etc files in each submodule and directory for details. If you distribute a built version of Proton to other users, you must adhere to the terms of these licenses.

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Runtime Config Options

Proton can be tuned at runtime to help certain games run. The Steam client sets some options for known games using the STEAM_COMPAT_CONFIG variable. You can override these options using the environment variables described below. The best way to set these environment overrides for all games is by renaming user_settings.sample.py to user_settings.py and modifying it appropriately. If you want to change the runtime configuration for a specific game, you can use the Set Launch Options setting in the game's Properties dialog in the Steam client. You can launch the game as you would with "PROTON_VARIABLE=1 %command%" (source).

To enable an option, set the variable to a non-0 value. To disable an option, set the variable to 0. To use Steam's default configuration, do not specify the variable at all.

All of the below are runtime options. They do not effect permanent changes to the Wine prefix. Removing the option will revert to the previous behavior.

Compat config string	Environment Variable	Description
	PROTON_LOG	Convenience method for dumping a useful debug log to $HOME/steam-$APPID.log. For more thorough logging, use user_settings.py.
	PROTON_DUMP_DEBUG_COMMANDS	When running a game, Proton will write some useful debug scripts for that game into $PROTON_DEBUG_DIR/proton_$USER/.
	PROTON_DEBUG_DIR	Root directory for the Proton debug scripts, /tmp by default.
wined3d11	PROTON_USE_WINED3D11	Use OpenGL-based wined3d instead of Vulkan-based DXVK for d3d11.
nod3d11	PROTON_NO_D3D11	Disable d3d11.dll, for games which can fall back to and run better with d3d9.
noesync	PROTON_NO_ESYNC	Do not use eventfd-based in-process synchronization primitives.