Valve released SteamOS Beta a few days ago as an early first-look public release. Based on Debian 7, the new operating system comes with a session called SteamOS which is a modified Big Picture mode that uses a custom SteamOS Compositor (based on xcompmgr) optimized for Steam and gaming, and some other tweaks.
If you want to run the official SteamOS session along with the custom SteamOS compositor in Ubuntu, you can easily do so by installing two packages. Once you install these packages, you'll be able to directly log in to the SteamOS session from the LightDM login screen.
This session is useful because it doesn't load a complete desktop environment so more resources are available for both Steam and games. However, since SteamOS is in its early development stages, so is this session, so expect to find bugs!
Here are some observations from my testing (please read!):
- this session loads Steam in Big Picture mode and from my experience and from what I've read, Big Picture is pretty buggy on Linux so before using this, I suggest trying the Big Picture Mode from the Steam Linux client and see if it works on your hardware/drivers, if games run properly and so on;
- the SteamOS session doesn't work if multiple monitors are plugged in. That means that even if a monitor is connected but disabled, the SteamOS session won't work and you'll get a black screen! To avoid this, make sure you boot with only one monitor connected or restart LightDM / logout after disconnecting a monitor.
- to get a "Return to desktop" power menu option in the SteamOS session, in the Steam Big Picture interface settings select Interface > Enable access to the Linux desktop. In my test, selecting "Return to desktop" didn't work with Ubuntu 14.04 and 13.10 but it worked on 12.10 (and it also didn't work with SteamOS running in VirtualBox when logging in to the SteamOS session). So if it doesn't work for you, exit the session either by selecting "Shutdown" or "Restart" from the Steam Big Picture power menu or restart LightDM (press Ctrl + Alt + F1, login and type: "sudo service lightdm restart", then press Ctrl + Alt + F7 to return to the login screen).
Tip: if you only want to run the "SteamOS" mode without having a session for it in the login screen, without the SteamOS compositor and so on, you can simply run the Steam client using the following command: "steam -steamos -tenfoot" and you'll get the SteamOS interface running on your desktop (for this to work, make sure your Steam for Linux client is up to date).
Install SteamOS session in Ubuntu
1. Firstly, install the Steam Linux client if you haven't already (you can install it via Ubuntu Software Center or by downloading the deb from its website). Also, make sure your Steam Linux client is up to date: Steam > Check for Steam Client Updates
2. To be able to use the SteamOS session in Ubuntu, you need two packages:
- SteamOS Compositor (includes the Compositor obviously and the actual session);
- SteamOS Modeswitch Inhibitor (even though the SteamOS Compositor deb doesn't depend on this package, it is used in the session file so I suggest you install it.
Using the links above, download and install SteamOS Compositor and SteamOS Modeswitch Inhibitor for your architecture. Then, log out and select "SteamOS" from the login screen:
Removing the SteamOS session
If you want to revert the changes, simply remove the two installed packages:
And when you log out, the SteamOS session shouldn't be displayed any more.
sudo apt-get remove steamos-compositor steamos-modeswitch-inhibitor