Add ‘Steam Deck Mode’ to existing Nobara installation

Some users may prefer to keep their current desktop installation and instead just add the ‘Steam Deck Mode’ aka ‘Game Mode’ session to their current setup.

To do this, install the following packages:

sudo dnf install gamescope gamescope-session-plus gamescope-session-steam gamescope-htpc-common

For additional support for things like gyro and tdp, optionally also install

sudo dnf install ryzenadj sdgyrodsu

These should be enough to work on both gnome and kde.

For a full KDE conversion, also install:

sudo dnf install kde-steamdeck kde-steamdeck-additions

At this point you can log out, then:

On SDDM/KDE: At the login screen choose ‘Steam Deck Mode’ from the session drop down menu.

On GDM/GNOME: At the login screen click the gear icon and choose ‘Steam Deck Mode’

Lastly, if you want the system to boot directly into ‘Steam Deck Mode’ aka ‘Game Mode’:

For SDDM

open /etc/sddm.conf and edit the following:

By default Nobara installs with auto-login enabled. If you declined this, you need to add this section:

[Autologin]
User=username
Session=gamescope-session-steam.desktop

If you already have the auto-login section, just change:

Session=plasma.desktop

to

Session=gamescope-session-steam.desktop

Then reboot.

For GDM:

open /etc/gdm/custom.conf and edit the following:

By default Nobara installs with auto-login enabled. If you declined this, you need to add this section:

[daemon]
AutomaticLogin=username
AutomaticLoginEnable=True

Next, you need to change the default session used by GDM. To do this, open as root /var/lib/AccountsService/users/username (replace username with your username), and change:

Session=gnome
XSession=gnome

to:

Session=gamescope-session-steam
XSession=gamescope-session-steam

Then reboot.