New x86_64 host for a 4th-gen Core i7 (Haswell) with a GTX 1070 8 GB, wired to a television and driven with a Bluetooth controller. Session: greetd gets an initial_session, so the machine autologins into the gamescope Steam session at boot with no greeter and no keyboard. Quitting Steam falls back to greetd's default_session (ReGreet), where the ordinary Sway session is available for keyboard-and-mouse work. Graphics: the GTX 1070 is Pascal, so it needs driver branch 580 (nvidiaPackages.legacy_580) like the Mac Pro's Quadro P400 -- the nixpkgs default (production, 595.x) dropped Pascal support. Games: RetroArch built through retroarch-bare.wrapper with 17 cores covering NES through PS2, GameCube and Wii; Clone Hero; and Steam with Proton-GE and protontricks. RetroArch's menu toggle is bound to L3+R3, without which there is no way to exit a running core on a machine with no keyboard. Proton prerequisites beyond what programs.steam already arranges: the esync file-descriptor hard limit is raised from systemd's default 524288 to 1048576 (soft limit untouched), and Proton-GE is wired in via extraCompatPackages. vm.max_map_count already defaults high enough in nixpkgs and needs no override. Content lives in a shared /srv/games tree created by systemd.tmpfiles, laid out one directory per system under roms/ using the libretro/ES-DE naming convention, plus bios/, saves/, states/, a Steam library folder and Clone Hero's songs. RetroArch is pointed at it declaratively. hardware-configuration.nix is a placeholder, not a hardware scan: the machine is not installed yet. It assumes partition labels `nixos` and `BOOT` and must be replaced with nixos-generate-config output. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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Console — living-room games machine
Flake host: lyrathorpe-console. Desktop (portable = false, imports
../../modules/desktop.nix). Files: configuration.nix, nvidia.nix,
gaming.nix, hardware-configuration.nix.
A 4th-generation Core i7 (Haswell) on a UEFI board with an NVIDIA GeForce GTX 1070 8 GB, wired to a television. It boots straight into Steam Big Picture and is driven from the sofa with a Bluetooth controller; keyboard and mouse are supported but secondary.
Not installed yet
hardware-configuration.nix in this host directory is a placeholder, not a
hardware scan. It exists so the flake evaluates in CI and assumes the install
labels its partitions nixos (root, ext4) and BOOT (ESP, vfat). Replace the
whole file with the output of nixos-generate-config run on the machine and
commit that. If the labels do not match, the boot fails on a missing device
rather than touching the wrong disk.
Partition the disk GPT with an ESP (vfat, 512 MB is comfortable). Nothing else in the host config depends on the disk layout.
Bootloader
Ordinary PC UEFI firmware, so systemd-boot with
canTouchEfiVariables = true — unlike the Mac Pro, this board is trusted with
efibootmgr NVRAM writes.
boot.loader.timeout = 0: the boot menu is unreadable from a sofa and unusable
without a keyboard, so the default entry boots immediately. Hold space at
power-on to get the menu back and pick an older generation.
configurationLimit = 10 stops the ESP filling up.
Graphics — GTX 1070
Everything driver-related is in nvidia.nix.
The GTX 1070 is Pascal (GP104), so it is under the same driver constraint as the
Mac Pro's Quadro P400:
- Driver branch 580 (
nvidiaPackages.legacy_580), not the nixpkgs default (production, currently 595.x). 580 is the last branch supporting Maxwell/Pascal/Volta, maintained as an LTS branch until Aug 2028; a newer branch does not drive this card at all. modesetting.enable = true— mandatory for Wayland. Withoutnvidia-drm.modeset=1neither gamescope nor wlroots gets a usable GBM device, and both the Steam session and Sway fail to start.open = false— the open kernel modules require Turing or later.- Sway runs with
--unsupported-gpu; wlroots refuses the proprietary driver otherwise. gamescope and cage/ReGreet need no such flag. hardware.graphics.enable32Bitpulls in the lib32 NVIDIA userspace that 32-bit Steam titles and Proton's 32-bit prefixes link against.
The driver is unfree, so it is not in the binary cache: the kernel module is
compiled on the machine. On a Haswell i7 that is a few minutes, not the Mac
Pro's ordeal, but it recurs on every kernel bump. The package names are
allowlisted in unfreePackages in flake.nix.
Verify after a rebuild:
nvidia-smi
lsmod | grep nvidia # nvidia, nvidia_modeset, nvidia_drm
Session model — autologin into Steam
gaming.nix
sets programs.steam.gamescopeSession.enable, which registers a steam.desktop
Wayland session (gamescope wrapping Steam in tenfoot mode) and installs a
steam-gamescope launcher. greetd — already present on every Sway host for
ReGreet, see ../../modules/sway.nix
— gets an initial_session pointing at that launcher:
boot
└─ greetd initial_session (autologin as lyrathorpe)
└─ gamescope --steam -- steam -tenfoot -pipewire-dmabuf
├─ Steam library / Proton titles
├─ [non-Steam] RetroArch
└─ [non-Steam] Clone Hero
quit Steam → greetd default_session → ReGreet → pick Sway (keyboard + mouse)
So there is no greeter at boot and no keyboard needed. Quitting Steam drops back
to ReGreet, where the ordinary Sway session is available for everything else.
services.greetd.restart defaults to false once initial_session is set,
which is what stops a logout looping straight back into autologin.
Two details worth knowing:
- The launcher is referenced as
/run/current-system/sw/bin/steam-gamescope. The steam module builds that script privately and only adds it toenvironment.systemPackages, so there is no package attribute to point at. programs.gamescope.capSysNice = trueinstalls gamescope as a setcap wrapper in/run/wrappers/bininstead of the system profile. That path precedes the system profile onPATH, sosteam-gamescopestill resolves it.
The greeter is Dvorak, like every other host here (modules/sway.nix forces
XKB_DEFAULT_VARIANT=dvorak on cage). Only relevant if someone else has to type
a password.
Adding RetroArch and Clone Hero to Big Picture
Both are installed system-wide but are not Steam titles. Add each once, from a Sway session, via Steam's Games → Add a Non-Steam Game; they then appear in Big Picture and inherit Steam Input, so the controller works in them without further configuration.
Emulation — RetroArch
gaming.nix builds RetroArch through pkgs.retroarch-bare.wrapper, which wires
up the packaged assets, core info and joypad autoconfig profiles. Cores:
| System | Core |
|---|---|
| NES | nestopia |
| SNES | snes9x |
| Game Boy / Color | gambatte |
| Game Boy Advance | mgba |
| Nintendo 64 | mupen64plus |
| Nintendo DS | melonds |
| GameCube / Wii | dolphin |
| Master System / Game Gear / Mega Drive | genesis-plus-gx |
| 32X / Mega CD | picodrive |
| Saturn | beetle-saturn |
| Dreamcast / NAOMI | flycast |
| PlayStation | beetle-psx-hw |
| PlayStation 2 | pcsx2 (LRPS2) |
| PSP | ppsspp |
| Arcade | fbneo, mame2003-plus |
| DOS | dosbox-pure |
A handful of settings are applied on every launch via --appendconfig, so they
are fixed policy rather than saved preferences — changing them in the UI will
not stick. Everything else stays user-editable as normal.
menu_driver = ozone— the controller-navigable menu.video_fullscreen = true.input_menu_toggle_gamepad_combo = 2— L3+R3 opens the RetroArch menu from inside a running core. Without a pad combo there is no way to exit a game without a keyboard. No retro system emulated here has L3/R3 on its own controller, so the binding cannot collide with a game.system_directory,savefile_directory,savestate_directory,playlist_directory,screenshot_directory,thumbnails_directoryandrgui_browser_directory— all pointed at the shared library described below, rather than scattered through~/.config/retroarch.
An unrecognised key in an appended config is ignored silently, so those key names are worth keeping in step with upstream if RetroArch is ever bumped across a major version.
BIOS files and expectations
Several cores need BIOS or firmware images that are not redistributable and are
therefore not packaged. Drop them in /srv/games/bios, which is RetroArch's
system directory on this host:
- PlayStation 2 (
pcsx2) — a PS2 BIOS dump. The core will not boot anything without one. - Saturn (
beetle-saturn) — region BIOS images. - Dreamcast (
flycast) —dc_boot.bin/dc_flash.binfor most titles. - Nintendo DS (
melonds) — optional, but DSi mode and some titles want the real BIOS/firmware.
Be honest about the two heaviest cores. dolphin and pcsx2 are libretro ports
of emulators whose upstream effort goes into their standalone builds; the
cores lag on compatibility and are the first place to look when a GameCube, Wii
or PS2 title misbehaves. If a game does not cooperate, add the standalone
emulators to environment.systemPackages in gaming.nix:
pkgs.dolphin-emu # GameCube / Wii
pkgs.pcsx2 # PlayStation 2
Both are controller-driven and can be added to Big Picture the same way as RetroArch. The hardware is not the limit here — a GTX 1070 and a Haswell i7 run PS2 and Wii comfortably.
Five cores (snes9x, genesis-plus-gx, picodrive, fbneo,
mame2003-plus) carry upstream licences with non-commercial or
no-redistribution-for-profit clauses, so their derivation names are in
unfreePackages in flake.nix. Nothing else in the core set needs it.
Games library layout
Content lives under /srv/games, deliberately outside any home directory: it is
bulky, it is the thing most likely to move to its own disk, and it is shared
between Steam, RetroArch and Clone Hero rather than owned by one of them.
Mounting a second drive at /srv/games is the only change that move needs.
gaming.nix creates the tree with systemd.tmpfiles.rules at every boot:
/srv/games/
├── roms/ # RetroArch content browser opens here
│ ├── nes/ snes/ gb/ gbc/ gba/ n64/ nds/ gc/ wii/
│ ├── mastersystem/ gamegear/ megadrive/ sega32x/ segacd/
│ ├── saturn/ dreamcast/
│ ├── psx/ ps2/ psp/
│ └── arcade/ dos/
├── bios/ # RetroArch system dir: BIOS and firmware
├── saves/ # in-game saves
├── states/ # save states
├── playlists/
├── screenshots/
├── thumbnails/
├── steam/ # second Steam library folder
└── clonehero/
├── songs/
└── backgrounds/
Directory names under roms/ follow the libretro/ES-DE convention, so a scraper
or a second frontend recognises them without anything being renamed.
Everything is lyrathorpe:users mode 2775. The setgid bit matters: the
owning group is carried onto anything created inside, so a second account — or
an rsync from another machine — does not leave behind files the TV user cannot
write. The rules create directories if missing and otherwise leave them alone;
nothing here removes or rewrites content.
RetroArch is pointed at these paths declaratively. The other two have to be told once, in their own UIs:
- Steam — Settings → Storage → the
+control → add/srv/games/steamas a library folder. Games installed there survive a reinstall of the OS. - Clone Hero — set the song library path to
/srv/games/clonehero/songsfrom its settings screen. Clone Hero keeps its own config in~/.clonehero.
Steam and Proton
programs.steam.enable already arranges most of what Proton needs, and it is
worth recording so it is not re-litigated:
hardware.graphicswithenable32Bit— the 32-bit GL/Vulkan userspace Proton's 32-bit prefixes link against.- Steam's udev rules (
hardware.steam-hardware.enable) — controller and hidraw access, which is also what letsdualsensectltalk to a DualSense. - 32-bit PipeWire ALSA (
services.pipewire.alsa.support32Bit), derived fromalsa.enable, whichgaming.nixturns on for the older native titles that talk to ALSA directly rather than through the Pulse shim. - Wine's fonts — Liberation, DejaVu, FreeFont and the Noto set arrive with
fonts.enableDefaultPackagesplusmodules/common-nixos.nix. Liberation is metric-compatible with the Microsoft core fonts, so text lays out correctly without shipping unfreecorefonts. vm.max_map_countis 1048576 in the nixpkgs default sysctls, above what DX12 and Unreal titles need. No override required — this is the one people usually copy from Arch wiki posts and it is already handled.
What is not covered by default, and is set explicitly in gaming.nix:
systemd.settings.Manager.DefaultLimitNOFILE = "1024:1048576". esync opens one eventfd per Wine synchronisation object and runs out against systemd's default 524288 hard limit in the heaviest titles. Only the hard limit is raised; the soft limit stays at 1024, because lifting that breaksselect()-based programs elsewhere on the system.extraCompatPackages = [ pkgs.proton-ge-bin ]. The module puts itssteamcompattooloutput onSTEAM_EXTRA_COMPAT_TOOLS_PATHS, which is what makes GE-Proton appear in the client's compatibility list.protontricks.enable— winetricks against a Proton prefix, the standard repair when a title needs a runtime (dotnet, vcrun, Media Foundation) Proton does not ship.programs.gamemode.enable— applies the performance CPU governor around games that request it.
One thing is not declarative: Steam Play must be switched on in the client, once, per account — Settings → Compatibility → Enable Steam Play for all other titles. Nix cannot set this; it lives in Steam's own config.
Verify the Proton side after installing:
vulkaninfo --summary # 64-bit ICD
nvidia-smi # driver up
ulimit -Hn # expect 1048576
# in a game's launch options, to confirm esync/fsync are active:
# PROTON_LOG=1 %command% → ~/steam-<appid>.log
Controllers
- Xbox One / Series over Bluetooth —
hardware.xpadneo.enable. The out-of-tree driver; the in-kernelxpadhandles these badly over Bluetooth (wrong button mapping, no rumble). The module enables bluez itself. - Xbox 360, wired — in-kernel
xpad, autoloaded by udev on plug-in. Nothing to configure. The kernel is built withCONFIG_JOYSTICK_XPAD=m,CONFIG_JOYSTICK_XPAD_FF=y(rumble) andCONFIG_JOYSTICK_XPAD_LEDS=y. The 360 wireless PC receiver uses the same driver and works the same way. - DualSense / DualShock 4 — in-kernel
hid-playstation, over both USB and Bluetooth. No driver config.dualsensectlis installed for LED, battery and microphone control; it works because Steam's udev rules grant hidraw access. - Clone Hero guitars — plain USB HID gamepads, handled in-kernel. Nothing to configure.
hardware.bluetooth.powerOnBoot is set so the adapter is up before the Steam
session starts and a pad can reconnect unattended.
settings.General.Experimental = true is what enables battery level reporting
for Bluetooth gamepads — it is still behind bluez's experimental flag.
Pair a new controller from Big Picture (Settings → Controller), or from a
Sway session with bluetoothctl. If a pad connects but no input arrives, check
journalctl -b -u bluetooth and confirm hid_xpadneo is loaded
(lsmod | grep xpadneo).
The Xbox One / Series USB wireless dongle is deliberately not configured. It
needs hardware.xone.enable, which blacklists xpad — that would break the
wired 360 pads — as well as mt76x2u, and pulls in proprietary dongle firmware.
Not worth the side effects unless that dongle is actually in use, and if it ever
is, the 360 pads have to be re-tested.
Untested claims
This host has not been built or booted yet. Two things are worth watching on first boot:
- gamescope on the proprietary NVIDIA driver.
gaming.nixsetsGBM_BACKEND=nvidia-drmand__GLX_VENDOR_LIBRARY_NAME=nvidiafor the session, which is the standard fix, but the combination has a history of needing tweaks. If the session dies at startup, switch the greeter back to interactive by commenting outservices.greetd.settings.initial_session, log into Sway, and readjournalctl --user -b. - Television resolution and refresh. gamescope takes the output's native
mode by default. Add
gamescopeSession.args = [ "-W" "3840" "-H" "2160" "-r" "60" ]if a specific mode is wanted.
There is no HDMI-CEC configuration here, so the TV remote will not drive the box; that needs a Pulse-Eight adapter or a working CEC bridge on the board. Nothing boots to a splash screen either — Plymouth was left out deliberately, as early KMS with the proprietary driver makes it unreliable.
Networking
Wired NetworkManager from ../../modules/desktop.nix; modules/ssh.nix adds
key-only sshd, which is the practical way to administer a machine with no
keyboard attached. The firewall is default-deny (modules/workstation.nix);
Steam Remote Play and local network game transfers open their own ports through
programs.steam.