Linux handheld foundation

You can build the initial Linux host from source. It runs Game Boy, Game Boy Color and Game Boy Advance games with your own ROMs and saves. Its companion uses the existing portable core for supported retail English Gen 3 games. Other games have emulation only in this foundation.

Follow linux/README.md in the source repository for dependencies, native and TrimUI builds, controls, save paths and test commands. Use a separate data folder while testing. Existing emulator saves are never imported automatically.

The game and the companion both fit your screen at a sharp whole number scale, so text stays about the same size on a 640x480, 720x720 or 1280x720 handheld.

Press Y while you play to open the quick menu over the game: open the PC from wherever you stand, fly to a town you have been to, use the keep-away spray from your bag, get on or off your bike, turn wild encounters off or back on, save or load a state, fast forward or open the companion. Pick a tile with the D-pad and press A; B closes it. Flying needs a Pokémon in your party that knows the move and the badge the game asks for, just like in the game's own menu.

The HUD shows your party, a small map around you, the steps left on the spray and your balls over the overworld, out of the way of the game's own text. Turn it or any of its parts off in the companion's SETTINGS > HUD. In SETTINGS > TAB BAR you pick which tabs sit on the bar; the rest open from MORE.

Press the companion button to pause the game and open its companion. Use the D-pad to focus an option, A to choose it and B to go back. The shoulder buttons change tabs. Your game menu has cancel-first save, load and quit confirmations.

To see more of the map, set ASPECT in the companion's SETTINGS to EXPAND: the overworld reaches the edges of your screen at the same sharp scale as the game, for the games EXPAND knows on Android. ZOOM OUT shows even more of it, one scale smaller. Battles and menus stay as the game draws them, and with AUTO ZOOM IN on, so do text boxes.

On firmwares that run PortMaster (ROCKNIX, Knulli, muOS and others), the PortMaster build goes in your ports folder like any other port, with your games in its roms folder. Controllers can be plugged in while you play.

This early version does not include the Polished Crystal companion, the longer summaries or firmware power handling. Earlier builds ran on the Brick and Smart Pro, but this separated foundation still needs fresh device testing. Other Linux handhelds are not verified.