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Flatpak

Flatpak icon Flatpak logo

Overview

Flatpak is a portable Linux packaging format that lets you install modern applications in a sandboxed environment. REG-Linux exposes Flatpak apps through the flatpak system, which groups under the ports/pc category and shares the flatpak artwork set where available.

This system currently targets x86_64 hosts because most Flatpak packages are distributed for that architecture.

Quick reference

  • ROM folder: /userdata/roms/flatpak (stores shortcuts)
  • Saves folder: /userdata/saves/flatpak (where Flatpak runtimes and data live)
  • Accepted formats: .flatpak
  • Common tools: flatpak-config, flatpak-update, REG-Linux-flatpak-update

Installing Flatpaks

Step 1: add a repository

Flatpak uses remotes such as Flathub. On REG-Linux v31 you must add the repo manually via SSH or the system terminal:

flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

REG-Linux v32+ ships with Flathub already configured.

Step 2: install via flatpak-config

Open flatpak-config from Applications ([F1] → Applications) to search and install packages graphically.

Step 3: register the shortcut

After installing a Flatpak, run REG-Linux-flatpak-update over SSH or from the menu to add the application shortcut to the Ports category (/userdata/roms/flatpak).

Alternative: install via command line

From SSH, add the repo (if needed), then install a package by ID:

flatpak install com.valvesoftware.Steam

This downloads runtimes to /userdata/saves/flatpak and registers the shortcut in /userdata/roms/flatpak after you run REG-Linux-flatpak-update.

Managing Flatpaks

  • Update packages: run flatpak update or click Upgrade in flatpak-config.
  • Uninstall: use flatpak uninstall <app> or the UI, then delete the .flatpak shortcut from /userdata/roms/flatpak.
  • Clean unused runtimes: flatpak uninstall --unused removes orphaned dependencies.

Notes & limitations

  • Flatpaks may not yet support NAS save directories; use internal storage if you experience install failures.
  • Some apps rely on a keyboard/mouse; controllers often require pad-to-key mappings or Steam’s input layer.
  • Due to sandboxing, some games might need --no-sandbox or extra permissions; add those flags to the .sh script in Ports if necessary.

Controls

Flatpaks typically use keyboard/mouse input. Map your controller using Pad2Key in RetroArch or rely on the virtual keyboard overlay if the app lacks controller support.

Troubleshooting

  • App not launching: refresh game lists, ensure the Flatpak shortcut exists in /userdata/roms/flatpak, and try running with --no-sandbox.
  • Slow performance: make sure your GPU drivers are up to date (`dosent relevant?).
  • Controller issues: configure input in the app, use Steam/Proton helper packages, or check PCGamingWiki for solution tips.
  • Need to remove entire Flatpak environment: delete /userdata/saves/flatpak and /userdata/roms/flatpak.