Linux and the Steam Deck

The Linux build is the same game as the Windows one: a 32-bit x86 executable (ctr_native_ap in ctr-decrypted-vX.Y.Z-linux-x86.tar.gz, built in Debian 12 by .github/workflows/build.yml). It links only libc, libm and ld-linux.so.2 and needs glibc 2.38 or older (tools/ci/package-client.py refuses anything newer and records both in the archive's BUILD.json). SDL3 is linked in and loads X11 or Wayland, OpenGL, PulseAudio/ALSA/PipeWire and udev at run time, so the system needs their 32-bit libraries. SteamOS has them, since the Steam client is 32-bit.

To install on a Deck, follow SETUP.md: extract in Desktop Mode, add the disc image, Add to Steam, play in Gaming Mode.

What the game does on a Deck

• Detection. NativeConfig_IsSteamDeck (platform/native_config.c): the SteamDeck=1 variable Steam sets, or, for a launch outside Steam, a Valve board named Jupiter (LCD) or Galileo (OLED) in /sys/class/dmi/id.
• First launch. With no config.ini, a Deck starts fullscreen at 16:10 (NativeConfig_ApplyFirstLaunchDefaults); elsewhere it starts windowed 4:3. The Archipelago setup screen starts from these values. tools/test-graphics-options.c checks both.
• Fullscreen. Gaming Mode's gamescope never reports the window as fullscreen, so the setting is requested once, not every frame (NativeConfig_FullscreenNeedsReapply), and the cursor is hidden whenever the setting is on (Platform_UpdateCursorVisibility).
• Controller. Steam Input gives the game a virtual Xbox-style pad, which SDL maps like any other. Outside Steam, SDL's Steam Deck driver reads the built-in controls.
• Text. A connection field starts SDL text input with its area set, and SDL opens Steam's floating keyboard over it when SteamDeck=1. The pad can confirm or cancel the edit (NativeText_Resolve). The log's *Text input: lines say whether a screen keyboard was available.
• Audio. SDL tries PulseAudio, then ALSA, then PipeWire (NativeAudio_SelectDriverHint); SDL_AUDIO_DRIVER overrides it.

Testing on a Deck

CI has no Deck, so check a release by hand in Gaming Mode:

1. A first launch fills the screen at 16:10 with no cursor or black bars; Options shows Fullscreen on and Aspect Ratio 16:10.
2. The built-in controls drive the menus and a race, including L1/R1 and the triggers; the Controls menu lists the pad.
3. On the Connection screen, every field brings up the Steam keyboard, and Enter or X saves it.
4. Sound plays, a race runs smoothly at 60 FPS, and suspend and resume mid-race carries on.
5. Quitting from the menu returns to Steam; when a newer release exists, the updater installs it and restarts.

Report a problem in an issue with the support bundle (support-bundle.sh next to the game), which holds ctr-ap.log.