A binary compatible runtime environment for Steam applications on Linux.
This release of the steam-runtime SDK marks a change to a chroot environment used for building apps. A chroot environment is a standalone Linux environment rooted somewhere in your file system.
http://en.wikipedia.org/wiki/Chroot
All processes that run within the root run relative to that rooted environment. It is possible to install a differently versioned distribution within a root, than the native distribution. For example, it is possible to install an Ubuntu 12.04 chroot environment on an Ubuntu 14.04 system. Tools and utilities for building apps can be installed in the root using standard package management tools, since from the tool's perspective it is running in a native Linux environment. This makes it well suited for an SDK environment.
The Steam-runtime SDK relies on an APT repository that Valve has created that holds the packages contained within the steam-runtime. A single package, steamrt-dev, lists all the steam-runtime development packages (i.e. packages that contain headers and files required to build software with those libraries, and whose names end in -dev) as dependencies. Conceptually, a base chroot environment is created in the traditional way using debootstrap, steamrt-dev is then installed into this, and then a set of commonly used compilers and build tools are installed. It is expected that after this script sets the environment up, developers may want to install other packages / tools they may need into the chroot environment. If any of these packages contain runtime dependencies, then you will have to make sure to satisfy these yourself, as only the runtime dependencies of the steamrt-dev packages are included in the steam-runtime.
All the software that makes up the Steam Runtime is available in both source and binary form in the Steam Runtime repository http://repo.steampowered.com/steamrt
Included in this repository are scripts for building local copies of the Steam Runtime for testing and scripts for building Linux chroot environments suitable for building applications.
Steam ships with a copy of the Steam Runtime and all Steam Applications are launched within the runtime environment. For some scenarios, you may want to test an application with a different build of the runtime.
Current and past versions of the Steam Runtime are available from
http://repo.steampowered.com/steamrt-images-scout/snapshots/.
Beta builds, newer than the one included with Steam, are sometimes
available from the same location. The versioned directory names correspond
to the version.txt found in official Steam Runtime builds, typically
ubuntu12_32/steam-runtime/version.txt in a Steam installation.
The file steam-runtime.tar.xz in each directory contains the Steam
Runtime. It unpacks into a directory named steam-runtime/.
Each directory also contains various other archive and metadata files,
and a sources/ subdirectory with source code for all the packages that
went into this Steam Runtime release.
For advanced use, you can use the build-runtime.py script to build your own runtime. To get a Steam Runtime in a directory, run a command like:
./build-runtime.py --output=$(pwd)/runtime
The resulting directory is similar to the ubuntu12_32/steam-runtime
directory in a Steam installation.
To get a Steam Runtime in a compressed tar archive for easy transfer to other systems, similar to the official runtime deployed with the Steam client, use a command like:
./build-runtime.py --archive=$(pwd)/steam-runtime.tar.xz
To output a tarball and metadata files with automatically-generated
names in a directory, specify the name of an existing directory, or a
directory to be created with a / suffix:
./build-runtime.py --archive=$(pwd)/archives/
or to force a particular basename to be used for the tar archive and all
associated metadata files, end with .*, which will usually need to be
quoted to protect it from shell interpretation:
./build-runtime.py --archive="$(pwd)/archives/steam-runtime.*"
The archive will unpack into a directory named steam-runtime.
The --archive and --output options can be combined, but at least one
is required.
Run ./build-runtime.py --help for more options.
Once the runtime is downloaded (and unpacked into a directory, if you used an archive), you can use the run.sh script to launch any program within that runtime environment.
To launch Steam itself (and any Steam applications) within your runtime, set the STEAM_RUNTIME environment variable to point to your runtime directory;
~/.local/share/Steam$ STEAM_RUNTIME=~/rttest ./steam.sh
Running Steam on ubuntu 14.04 64-bit
STEAM_RUNTIME has been set by the user to: /home/username/rttest
To prevent libraries from development and build machines 'leaking' into your applications, you should build within a Steam Runtime chroot environment or container.
To obtain one, first find an appropriate directory in
http://repo.steampowered.com/steamrt-images-scout/snapshots/.
The versioned directory names correspond to the
version.txt found in official Steam Runtime builds, typically
ubuntu12_32/steam-runtime/version.txt in a Steam installation: you
should usually choose a build environment whose version matches the
Steam Runtime bundled with the current Steam release, or a slightly
older version.
To build 64-bit software, download the files named
com.valvesoftware.SteamRuntime.Sdk-amd64,i386-scout-sysroot.tar.gz and
com.valvesoftware.SteamRuntime.Sdk-amd64,i386-scout-sysroot.Dockerfile. To
build legacy 32-bit software, instead download
com.valvesoftware.SteamRuntime.Sdk-i386-scout-sysroot.tar.gz and
com.valvesoftware.SteamRuntime.Sdk-i386-scout-sysroot.Dockerfile.
Each directory also contains various other archive and metadata files,
and a sources/ subdirectory with source code for all the packages that
went into this Steam Runtime release.
The recommended way to build for the Steam Runtime is in a Docker
container. Put the -sysroot.tar.gz and -sysroot.Dockerfile files
in an otherwise empty directory, cd into that directory, and import
them into Docker with a command like:
sudo docker build \
-f com.valvesoftware.SteamRuntime.Sdk-amd64,i386-scout-sysroot.Dockerfile \
-t steamrt_scout_amd64:latest \
.
or for a 32-bit environment,
sudo docker build \
-f com.valvesoftware.SteamRuntime.Sdk-i386-scout-sysroot.Dockerfile \
-t steamrt_scout_i386:latest \
.
Both containers can co-exist side by side. 32 bit steam-runtime libraries
are installed into the i386 root, and 64 bit steam-runtime libraries
are installed into the amd64 root. You can keep old versions of the
container around by tagging them with a version instead of latest,
for example steamrt_scout_amd64:0.20190913.0.
For historical reasons, it is also possible to run setup_docker.sh.
This will download an Ubuntu 12.04 container and convert it into a Steam
Runtime environment. The result does not match the official sysroot
tarball and is not guaranteed to match any specific/identifiable version
of the Steam Runtime, so this approach is not recommended.
Alternatively, you can use Debian's schroot tool (this is likely to work
best on Debian or Ubuntu machines). setup_chroot.sh will create a
Steam Runtime chroot on your machine. This chroot environment contains
the same development libraries and tools as the Docker container. You will
need the 'schroot' tool installed, as well as root access through sudo.
For a 64-bit environment, use a command like:
./setup_chroot.sh --amd64 \
--tarball ~/Downloads/com.valvesoftware.SteamRuntime.Sdk-amd64,i386-scout-sysroot.tar.gz
or for a 32-bit environment,
./setup_chroot.sh --i386 \
--tarball ~/Downloads/com.valvesoftware.SteamRuntime.Sdk-i386-scout-sysroot.tar.gz
Both roots can co-exist side by side. 32 bit steam-runtime libraries are installed into the i386 root, and 64 bit steam-runtime libraries are installed into the amd64 root.
Once setup-chroot.sh completes, you can use the schroot command to execute any build operations within the Steam Runtime environment.
~/src/mygame$ schroot --chroot steamrt_scout_i386 -- make -f mygame.mak
The root should be set up so that the path containing the build tree is the same inside as outside the root. If this path is not within the current user's home directory tree, it should be added to /etc/schroot/default/fstab
Then the next time the root is entered, this path will be available inside the root.
The setup script can be re-run to re-create the schroot environment.
For historical reasons, it is possible to run setup_chroot.sh without
using the --tarball option. This will download a minimal Ubuntu 12.04
environment and convert it into a Steam Runtime environment. The result
is not guaranteed to match the official sysroot tarballs, and whether
it succeeds is heavily dependent on the operating system on which you
are running the tool, so this approach is no longer recommended.
By default, a build environment is created that contains:
- gcc-4.6
- gcc-4.8 (default)
- gcc-5
- clang-3.4
- clang-3.6
- clang-3.8
Switching default compilers can be done by entering the chroot environment:
~$ schroot --chroot steamrt_scout_i386
(steamrt_scout_i386):~$ # for gcc-4.6
(steamrt_scout_i386):~$ update-alternatives --auto gcc
(steamrt_scout_i386):~$ update-alternatives --auto g++
(steamrt_scout_i386):~$ update-alternatives --auto cpp-bin
(steamrt_scout_i386):~$ # for gcc-4.8
(steamrt_scout_i386):~$ update-alternatives --set gcc /usr/bin/gcc-4.8
(steamrt_scout_i386):~$ update-alternatives --set g++ /usr/bin/g++-4.8
(steamrt_scout_i386):~$ update-alternatives --set cpp-bin /usr/bin/cpp-4.8
(steamrt_scout_i386):~$ # for clang-3.4
(steamrt_scout_i386):~$ update-alternatives --set gcc /usr/bin/clang-3.4
(steamrt_scout_i386):~$ update-alternatives --set g++ /usr/bin/clang++-3.4
(steamrt_scout_i386):~$ update-alternatives --set cpp-bin /usr/bin/cpp-4.8
(steamrt_scout_i386):~$ # for clang-3.6
(steamrt_scout_i386):~$ update-alternatives --set gcc /usr/bin/clang-3.6
(steamrt_scout_i386):~$ update-alternatives --set g++ /usr/bin/clang++-3.6
(steamrt_scout_i386):~$ update-alternatives --set cpp-bin /usr/bin/cpp-4.8