For best results, launch with Gamescope, so apps can launch inside of Steam. You may want to tweak the command line options depending of your setup.
| Name | Description |
|---|---|
| -e | Enable Steam integration |
| --backend | Select the backend (usually drm, wayland, sdl or headless) |
| --expose-wayland | Important for launching native Wayland clients |
| -f | Fullscreen |
| -g | Grab the keyboard |
| -W, -H | Window width and height |
| --help | Check out the rest of the options |
[Desktop Entry] Name=Steam Big Picture Mode Comment=Start Steam in Big Picture Mode Exec=/usr/bin/gamescope -e --expose-wayland --backend wayland --prefer-vk-device --disable-layers -- env WLR_RENDERER_ALLOW_SOFTWARE=1 steam -tenfoot -steamdeck Type=Application
You can use drm or wayland for the backend option. Then you can configure SDDM to autostart Steam:
[Autologin] User=yuki Session=steam-big-picture
Works better if the above doesn't work. Also, lets you easily access the desktop without having to quit Steam. Start a desktop session (such as KDE), create an icon with this desktop file, add it to ~/.local/share/applications/, and link it in ~/.config/autostart/:
[Desktop Entry] Name=Steam Big Picture Mode Comment=Start Steam in Big Picture Mode Exec=/usr/bin/env WLR_RENDERER_ALLOW_SOFTWARE=1 gamescope -e -W 1920 -H 1080 -f -g --expose-wayland --backend sdl -- /usr/bin/steam -tenfoot -steamdeck Type=Application Icon=steam
You can use sdl or wayland for the backend option. Don't forget SDDM's autologin:
[Autologin] User=yuki Session=plasma