# Hardware support

How Nomarchy enables CPUs, GPUs, laptops, firmware, and peripherals — and
what to do when your machine is not in the happy path.

> **Queue:** [`agent/BACKLOG.md`](../agent/BACKLOG.md) (PROPOSED › Hardware
> product). Product framing: [`VISION.md`](VISION.md) § A. Design history:
> [`ROADMAP.md`](ROADMAP.md). Docs map: [`README.md`](README.md).
> Migration: [`MIGRATION.md`](MIGRATION.md).

## 1. Architecture (three layers)

Nomarchy does **not** reimplement [nixos-hardware](https://github.com/NixOS/nixos-hardware).
It stacks:

```
┌─────────────────────────────────────────────────────────────────────┐
│  A. Always-on desktop floor                                         │
│     modules/nixos/default.nix + power.nix + audio/BT                │
│     redistributable firmware · fwupd · NM · PipeWire · PPD · ddcci  │
└───────────────────────────────┬─────────────────────────────────────┘
                                │
┌───────────────────────────────▼─────────────────────────────────────┐
│  B. nixos-hardware profiles  (via mkFlake hardwareProfile)          │
│     common-cpu-* · common-gpu-* · common-pc(-laptop|-ssd) · model   │
│     microcode · GPU media · fstrim · vendor/model quirks            │
└───────────────────────────────┬─────────────────────────────────────┘
                                │
┌───────────────────────────────▼─────────────────────────────────────┐
│  C. nomarchy.hardware.*  (modules/nixos/hardware.nix)               │
│     gap above commons: GuC · amd-pstate · VA-API env · fprintd ·    │
│     IR-webcam hide · ROCm/NPU/latestKernel · I2C/DDC/CI             │
└─────────────────────────────────────────────────────────────────────┘
```

| Layer | Who turns it on | Where it lives |
|-------|-----------------|----------------|
| **A** | Distro defaults (`mkDefault`) | Any machine importing `nomarchy.nixosModules.nomarchy` |
| **B** | Installer DMI/`lspci` → `hardwareProfile = [ … ]` | Downstream `flake.nix` (`mkFlake`) |
| **C** | Installer probes → `system.nix`, or hand-edit | Downstream `system.nix` |

`hardware-configuration.nix` (from `nixos-generate-config`) still owns
initrd modules, filesystems, and the usual generate-config flags. The
installer writes a real one; the template ships a placeholder you must
replace.

Unknown `hardwareProfile` names **fail at eval** with Levenshtein
suggestions (`lib.nix`) — never silently ignored.

## 2. What works without thinking about it

These ship on every Nomarchy system unless you override them:

| Capability | Default | Notes |
|------------|---------|--------|
| Wi‑Fi / BT firmware blobs | `hardware.enableRedistributableFirmware` | iwlwifi, ath, rtw, brcm, SOF, … |
| NetworkManager | on | Wi‑Fi UI: System › Network |
| PipeWire + WirePlumber | on | |
| Bluetooth + blueman | on | System › Bluetooth |
| power-profiles-daemon | on | Menu + Waybar; TLP via `nomarchy.system.power.backend = "tlp"` |
| External monitor brightness | `nomarchy.hardware.i2c.ddcci` **on** | DDC/CI → backlight devices |
| Firmware updates (LVFS) | `services.fwupd.enable` | **Never auto-flashes** — see §4 |
| SMART / UPower / pcscd (FIDO) | on | |
| earlyoom | on | Process-level OOM, not cgroup kill of the whole session |

**Not** default-on (need detect or uncomment): fprintd, GuC/HuC,
amd-pstate, ROCm, NPU, thermald, charge limit, snapper (installer enables
snapper), `latestKernel`.

## 3. Install path (best experience)

`nomarchy-install` sources `pkgs/nomarchy-install/hardware-db.sh` and:

1. Probes CPU vendor, GPUs (`lspci`), battery, SSD, fingerprint USB VIDs,
   RGB+IR webcam names, NPU PCI class.
2. Looks up DMI `sys_vendor` × `product_name` in a ~60-entry model table
   (Framework, Dell XPS/Latitude, ThinkPad, Surface, ASUS ROG, Apple T2,
   System76).
3. Emits `MODULE …` lines → `hardwareProfile` list in `flake.nix`.
4. Emits `NOMARCHY hardware.*=…` → active + commented blocks in
   `system.nix`.
5. Asks you to confirm profiles (or pick manually from the full
   nixos-hardware attr list baked into the ISO). Override with
   `NOMARCHY_HW=auto|none|"mod1 mod2"`.

**Live ISO** is intentionally *generic* (no model profile): broad GPU
modules as *available*, redistributable firmware on, no baked
`nomarchy.hardware.*`. Tuning happens at install time.

Out of scope for the installer today: aarch64 (Pi, Snapdragon X), Steam
Deck (Jovian), Apple Silicon (T2 Intel Macs only in the DB).

## 4. Firmware updates (deep dive)

### What we ship

```nix
# modules/nixos/default.nix
services.fwupd.enable = lib.mkDefault true;
```

fwupd talks to the [LVFS](https://fwupd.org/): UEFI capsule (BIOS), some
SSDs, docks, Thunderbolt controllers, peripherals. It **only refreshes
metadata** on its own. Applying an update is always an explicit user
action.

### What you do today (CLI)

```sh
# After first boot (and occasionally later):
fwupdmgr refresh          # optional; daemon often has metadata
fwupdmgr get-devices      # what LVFS can see
fwupdmgr get-updates      # pending
fwupdmgr update           # apply (may need reboot / battery / AC)
```

Disable on VMs/headless: `services.fwupd.enable = false;` in `system.nix`.

### Why this is under-discovered

| Present | Missing |
|---------|---------|
| Daemon + package | Menu entry / Control Center |
| README one-liner | First-boot / MOTD hint |
| | Doctor check (“updates available”) |
| | Waybar / updates panel integration |

**Product direction (queued):** System › Firmware (or a Doctor section)
that runs refresh → list → confirm → `fwupdmgr update`, plus a short
post-install note when `fwupd` is enabled. Never auto-flash; pillar 1
(rock-stable) forbids silent BIOS writes.

### Thunderbolt

Firmware for TB devices may appear via LVFS. There is **no** first-class
`services.hardware.bolt` / security-level UI in Nomarchy — use plain
NixOS options if you need bolt.

### Microcode / kernel firmware

- **CPU microcode:** from nixos-hardware `common-cpu-*` and
  `nixos-generate-config` once redistributable firmware is on — not a
  separate `nomarchy.*` toggle.
- **GPU GuC/HuC (Intel i915):** `nomarchy.hardware.intel.guc` →
  `i915.enable_guc=3`. Installer turns this **off** when the bound driver
  is `xe` (GuC is default there; the param is ignored).
- **`hardware.enableAllFirmware`:** not set. Oddball non-redistributable
  Wi‑Fi still needs a manual NixOS fix (or a broader policy decision).

## 5. Fingerprint (deep dive)

### Detect → enable

Installer scans USB vendor IDs common to libfprint (Goodix, Synaptics,
Elan, …) via `lsusb` or `/sys/bus/usb/.../idVendor`. On hit:

```nix
nomarchy.hardware.fingerprint.enable = true;  # services.fprintd
# nomarchy.hardware.fingerprint.pam = true;   # login + sudo (opt-in)
```

### Enroll (CLI today)

```sh
fprintd-enroll            # as your user
fprintd-list "$USER"
# then, if you want login/sudo:
# uncomment fingerprint.pam in system.nix → sys-rebuild
```

PAM stays opt-in on purpose: password-only remains the cautious default
until a finger is enrolled.

### Gaps

- No System menu “Fingerprint” row (enroll / list / delete).
- No “use for login” toggle that writes state + rebuild note.
- Doctor does not check reader presence or enroll status.

**Product direction (queued):** when `fprintd` is active, a self-gated
menu module for enroll/list; optional PAM toggle via state + rebuild
hint (same pattern as Bluetooth in Control Center).

## 6. NVIDIA (deep dive)

### What happens at install

```
lspci → NVIDIA  ⇒  MODULE common-gpu-nvidia
```

That is the **entire** Nomarchy surface. Unfree packages are allowed
(`allowUnfree = true` in the module and in `mkFlake`), so the proprietary
path from nixos-hardware can evaluate.

There is **no** `nomarchy.hardware.nvidia.*` for:

- hybrid / PRIME (Intel+NVIDIA, AMD+NVIDIA)
- open vs closed kernel module
- power management / udev / suspend quirks
- CUDA / container toolkit packages

### What a hybrid laptop user must do today

1. Confirm `common-gpu-nvidia` (and often `common-gpu-intel` or
   `common-gpu-amd`) are in `hardwareProfile`.
2. Read the relevant nixos-hardware module and [NixOS NVIDIA wiki](https://wiki.nixos.org/wiki/Nvidia).
3. Add plain NixOS options in `system.nix`, for example (illustrative —
   hardware-specific):

```nix
# Example only — verify against your generation and nixos-hardware module.
# hardware.nvidia.prime = { ... };
# hardware.nvidia.powerManagement.enable = true;
# hardware.nvidia.open = false;  # or true for open modules on newer cards
```

4. Rebuild the system. Home Manager does not own the driver.

### Live ISO note

The ISO lists `nouveau` among *available* initrd modules and does **not**
force-load every GPU driver (avoids multi-driver panics). Proprietary
NVIDIA on the live session is not the product focus; installed systems
use the profile.

**Product direction (queued):** when detection selects
`common-gpu-nvidia`, emit a **commented** `system.nix` block with PRIME /
power / open-module pointers (same pattern as ROCm / NPU comments), not
a full second NVIDIA stack unless a maintainer commits to testing.

## 7. Day-2: “my laptop is mostly fine, make it fully fine”

| Goal | How | Rebuild? |
|------|-----|----------|
| Power profile (perf/balanced/saver) | System menu / Waybar | No (PPD D-Bus) |
| Charge limit 80% | Menu / `settings.power.batteryChargeLimit` | System (sysfs apply is separate backlog) |
| Thermald (Intel) | Installer on for Intel laptops; else `power.thermal.enable` | System |
| Fingerprint enroll | `fprintd-enroll` | No |
| Fingerprint login | `fingerprint.pam = true` | System |
| ROCm / Intel compute | Uncomment opt-ins in `system.nix` | System (large) |
| NPU driver | Uncomment `npu` (+ often `latestKernel`) | System; userspace BYO |
| Newer kernel for brand-new silicon | `nomarchy.hardware.latestKernel = true` | System |
| Hide IR “dark camera” | Installer or `camera.hideIrSensor` | System |
| Firmware | `fwupdmgr update` | Reboot if capsule requires |
| Model quirks missing | Set better `hardwareProfile` (see §8) | System |
| OpenRGB / printing / Steam | `nomarchy.services.*` | System |

Theme switches never touch drivers (Home Manager only).

## 8. Unsupported or unlisted machines

### Still good floor

Even with **no** DMI hit you usually get:

- `common-cpu-{intel,amd}`
- `common-gpu-{intel,amd,nvidia}` as applicable
- `common-pc` or `common-pc-laptop` + optional `common-pc-ssd`
- `nomarchy.hardware.intel` or `.amd` when vendor matches
- Layer A (firmware, audio, BT, PPD, fwupd)

You **lose** model-specific EC/suspend/keyboard/audio quirks that only
exist in a named nixos-hardware module.

### Pick a profile after install

1. List candidates:

   ```sh
   nix eval github:NixOS/nixos-hardware#nixosModules \
     --apply builtins.attrNames
   # or: the ISO ships hardware-modules.txt for the same list
   ```

2. Set in your flake (installer already uses a list):

   ```nix
   hardwareProfile = [
     "common-cpu-amd"
     "common-gpu-amd"
     "common-pc-laptop"
     "common-pc-ssd"
     "lenovo-thinkpad-t14-amd-gen3"  # if it matches
   ];
   ```

3. `sudo nixos-rebuild switch --flake ~/.nomarchy#default`

### Template / migration (no installer)

See [MIGRATION.md](MIGRATION.md): reuse `hardware-configuration.nix`, set
`hardwareProfile`, uncomment `nomarchy.hardware` / power in `system.nix`.
There is **no** post-install re-probe helper yet (queued as
`nomarchy-detect-hw`).

### Re-detect sketch (future)

The installer’s `nomarchy_detect_hw` is already a pure probe (stdout
lines only). Exposing it as a package on PATH that prints suggested
`hardwareProfile` + `system.nix` snippets would close the template gap
without reinstalling.

## 9. Adding your model to the distro

For contributors (and power users who will PR):

1. On the machine:

   ```sh
   cat /sys/class/dmi/id/sys_vendor
   cat /sys/class/dmi/id/product_name
   ```

2. Find a matching attr in
   [nixos-hardware](https://github.com/NixOS/nixos-hardware) (or add one
   upstream first).

3. Append to `pkgs/nomarchy-install/hardware-db.sh` in `HARDWARE_DB`:

   ```bash
   "VendorRegex|Product regex|nixos-hardware-module-name"
   ```

   First match wins — put specific lines above broad fallbacks.

4. Verify the name exists in the **pinned** nixos-hardware input
   (`mkFlake` will throw if not). A CI check that every DB name ∈
   `nixosModules` is queued so lock bumps cannot silently break installs.

5. Optional: note on-hardware QA steps in `agent/HARDWARE-QUEUE.md`.

## 10. Doctor and hardware health (current vs target)

**Today** (`nomarchy-doctor`): failed units, disk space, theme-state
validity/git, generation age, snapper timer. **No** Wi‑Fi, GPU, fwupd,
or fingerprint checks.

**Target checks** (queued, all read-only, each failure prints one fix
command — same doctor contract):

| Check | Pass condition | Suggested fix line |
|-------|----------------|--------------------|
| NetworkManager | device connected or wifi radio on | open System › Network |
| Audio sink | default sink exists | System › Audio |
| GPU accel | `glxinfo`/`vainfo` smoke (if installed) | check `hardwareProfile` / drivers |
| Fingerprint | if USB VID matched / fprintd unit | `fprintd-enroll` or enable option |
| fwupd | daemon active; optional “updates pending” warn | `fwupdmgr get-updates` |
| Battery threshold | if laptop + limit set, sysfs writable | power docs |

## 11. Option quick reference

Full tables: [README § options](../README.md). Hardware-shaped surface:

| Option | Role |
|--------|------|
| `mkFlake.hardwareProfile` | nixos-hardware name or list |
| `nomarchy.hardware.intel.enable` / `.guc` / `.computeRuntime` | Intel gap layer |
| `nomarchy.hardware.amd.enable` / `.pstate` / `.vaapi` / `.rocm.*` | AMD gap layer |
| `nomarchy.hardware.fingerprint.enable` / `.pam` | fprintd + PAM |
| `nomarchy.hardware.npu.enable` | in-kernel NPU only |
| `nomarchy.hardware.latestKernel` | `linuxPackages_latest` |
| `nomarchy.hardware.camera.hideIrSensor` / `.irMatch` | dual-sensor webcams |
| `nomarchy.hardware.i2c.enable` / `.ddcci` | I2C + external backlight |
| `nomarchy.system.power.*` | PPD/TLP, laptop, thermald, charge limit |
| `nomarchy.system.bluetooth.enable` | BT stack |
| `services.fwupd.enable` | LVFS (native NixOS, default on) |

## 12. Ease summary

| Situation | Effort |
|-----------|--------|
| Known model in DB (Framework, many ThinkPads, …) | Low — install and go |
| Unknown modern Intel/AMD laptop | Low–medium — commons cover a lot |
| Firmware updates | Medium — CLI only until product work lands |
| Fingerprint for login | Medium — enroll CLI + PAM uncomment |
| Hybrid NVIDIA | High — plain NixOS/wiki territory |
| ROCm / NPU userspace | High — opt-in + expert |
| Contribute a new DMI line | Medium for someone who can PR |

## 13. Related files

| Path | Role |
|------|------|
| `modules/nixos/hardware.nix` | `nomarchy.hardware.*` |
| `modules/nixos/power.nix` | PPD/TLP, charge limit, thermald |
| `modules/nixos/default.nix` | firmware, fwupd, ddcci default |
| `pkgs/nomarchy-install/hardware-db.sh` | DMI DB + probes |
| `pkgs/nomarchy-install/nomarchy-install.sh` | writes flake + system.nix |
| `lib.nix` | `hardwareProfile` resolution |
| `templates/downstream/system.nix` | commented opt-ins |
| `agent/HARDWARE-QUEUE.md` | on-machine V3 checks |