Emulators Flake for NixOS

Overview

This Nix flake provides a collection of emulators for running games and applications from various platforms on NixOS, without polluting your system-wide configuration. It leverages Nix Flakes for isolated, reproducible environments, making it ideal for retro gaming enthusiasts and developers testing across platforms. Supported emulators include:

• PPSSPP: PlayStation Portable (PSP)
• PCSX2: PlayStation 2 (PS2)
• RPCS3: PlayStation 3 (PS3)
• Xenia Canary: Xbox 360
• Android Emulator: Android (Pixel 7 AVD with Play Store)
• Dolphin: Nintendo GameCube and Wii
• DOSBox: MS-DOS

Whether you’re reliving classics like Midnight Club or testing Android apps, this flake keeps everything neatly contained.

Prerequisites

• NixOS: Any recent version (e.g., 23.11 or 24.05) with Flakes enabled.
• Hardware:
  • Minimum: Intel i5/Ryzen 5, 8GB RAM, GPU with OpenGL/Vulkan (e.g., GTX 1050).
  • Recommended: Ryzen 7, 16GB+ RAM, RTX 3060 for PS3/Xbox 360/Android.
• KVM: Required for Android and Dolphin hardware acceleration (see Setup).
• ROMs: Legally dumped game files (e.g., .iso, .exe) from your own media.

Installation

1. Enable Flakes (if not already):

   • Edit /etc/nixos/configuration.nix or ~/.config/nix/nix.conf:

     experimental-features = nix-command flakes

   • Rebuild: sudo nixos-rebuild switch.

2. Clone the Flake:

   git clone <repo_url>
   cd <project_name>

3. Lock Dependencies:

   • Cache inputs and verify hashes:

     nix flake lock

4. Optional: Build All Apps:

   • Test the build process:

     for app in ppsspp pcsx2 rpcs3 xenia android dolphin dosbox; do nix build .#$app; done

Setup

General Setup

• Place ROMs in a directory (e.g., ~/roms/) for easy access.
• Connect a gamepad (Xbox/PS) via USB/Bluetooth

Emulator-Specific Setup

• PPSSPP: No extra setup; load ROMs via GUI.
• PCSX2:
  • Dump your PS2 BIOS (e.g., scph10000.bin) and place it in ~/.config/PCSX2/bios/.
• RPCS3:
  • Download PS3 firmware (.PUP) from playstation.com.
  • Install it via RPCS3 GUI (File > Install Firmware).
• Xenia: No BIOS needed; ensure Wine works (test with nix-shell -p wineWowPackages.stable --run "wine --version").
• Android Emulator:
  • Enable KVM in your NixOS config:

    boot.kernelModules = [ "kvm-amd" ]; # or "kvm-intel"
    users.users.<your-user>.extraGroups = [ "kvm" ];

    Rebuild: sudo nixos-rebuild switch.
  • AVD (pixel_7) auto-creates on first run.
• Dolphin: Enable KVM (as above) for best performance; no BIOS required.
• DOSBox: Optional config file at ~/.dosbox/dosbox.conf.

Usage

Run emulators with nix run .#<app-name> from the <project_name> directory. Examples:

• PPSSPP: nix run .#ppsspp, then File > Load to select a .iso.
• PCSX2: nix run .#pcsx2, configure BIOS, load .iso via GUI.
• RPCS3: nix run .#rpcs3, install firmware, add games via GUI.
• Xenia: nix run .#xenia /path/to/game.iso (follow Xenia docs).
• Android: nix run .#android (first run creates AVD; use adb for apps).
• Dolphin: nix run .#dolphin, load .iso or .wbfs via GUI.
• DOSBox: nix run .#dosbox -c "mount c /path/to/game" -c "c:" -c "game.exe".

For all emulators in one shell:

nix shell .#ppsspp .#pcsx2 .#rpcs3 .#xenia .#android .#dolphin .#dosbox

Configuration

Adjust settings via each emulator’s GUI or CLI:

• PPSSPP: Graphics/controls in Settings.
• PCSX2: Config > Video (Vulkan recommended), Config > Controllers.
• RPCS3: Config > GPU (Vulkan), Config > Pads.
• Xenia: Edit xenia.config.toml in game directory (see Xenia wiki).
• Android: Pass flags (e.g., nix run .#android -- -no-audio).
• Dolphin: Options > Graphics Settings (Vulkan/OpenGL).
• DOSBox: Edit ~/.dosbox/dosbox.conf or pass CLI flags.

Refer to official docs for details:

• PPSSPP
• PCSX2
• RPCS3
• Xenia
• Android
• Dolphin
• DOSBox

How to Run

From <project_name>/:

• Single emulator: nix run .#<app-name> (e.g., nix run .#dolphin).
• With arguments: Append flags (e.g., nix run .#dosbox /path/to/game.exe).
• Verify: If an emulator fails, check FAQ or run nix flake check.

How to Make Changes

1. Edit flake.nix:

   • Add emulators: Copy an apps entry (e.g., snes9x = { type = "app"; program = "${pkgs.snes9x}/bin/snes9x"; };).
   • Update Xenia SHA256: Re-run nix-prefetch-url --unpack <url> if the release changes.
   • Adjust Android version: Modify platformVersions (e.g., ["30"]).

2. Test Changes:

   • nix flake lock to update dependencies.
   • nix run .#<app-name> to test.

3. Commit:

   • git add flake.nix && git commit -m "Added SNES9x emulator".

FAQ

Common Errors/Issues

• "Hash mismatch" on Xenia:
  • Cause: New Xenia release updated the ZIP.
  • Fix: Re-run nix-prefetch-url --unpack https://github.com/xenia-canary/xenia-canary/releases/latest/download/xenia_canary.zip, update sha256 in flake.nix, then nix flake lock.
• "Failed to create AVD" on Android:
  • Cause: KVM not enabled or SDK issue.
  • Fix: Verify KVM (lsmod | grep kvm), check ~/.android/avd/pixel_7.avd/ logs, ensure android-sdk builds (nix build .#android).
• "PCSX2 won’t start":
  • Cause: Missing BIOS.
  • Fix: Place BIOS in ~/.config/PCSX2/bios/.
• "RPCS3 black screen":
  • Cause: No firmware.
  • Fix: Install .PUP via File > Install Firmware.

Common Questions

• Can I use a stable Nixpkgs version?:
  • Yes, change nixpkgs.url to "github:NixOS/nixpkgs/nixos-23.11" for stability.
• How do I add a new emulator?:
  • Add to apps (e.g., citra = { type = "app"; program = "${pkgs.citra}/bin/citra-qt"; };), then nix flake lock.
• Why Android Play Store?:
  • Included for app testing; switch to "google_apis" in systemImageTypes for a lighter image.
• Performance slow?:
  • Check GPU drivers (nvidia-driver or Mesa), enable KVM, upscale conservatively (e.g., 720p for PS3).

Contributing

Contributions welcome! Fork the repo, make changes, and submit a PR. See “How to Make Changes” for guidance.

License

MIT License - see LICENSE file.

Acknowledgments

• NixOS community for Flakes and emulator packages.
• Emulator developers: PPSSPP, PCSX2, RPCS3, Xenia, Android, Dolphin, DOSBox teams.