The module is intended to complement the NVIDIA support already provided by Nixpkgs. It does not replace the existing NixOS NVIDIA module; it only adds automatic driver selection based on the detected PCI device IDs.

What it does #

When imported, the module:

Reads the NVIDIA devices from the nix-facter hardware report.
Extracts the PCI vendor and device IDs.
Matches the device ID against known NVIDIA GPU families.
Selects the corresponding driver package from hardware.nvidia.package.
Enables the required NVIDIA configuration.

No additional enable option is required.

For example:

{
  imports = [
    inputs.asgard.nixosModules.facter
  ];
}

If an NVIDIA GPU is present in the facter report, the appropriate driver is selected automatically.

Supported driver families #

The module currently maps GPUs to the following driver branches:

Driver	GPU families
`stable`	Pascal and newer
`legacy_470`	Maxwell and late Kepler
`legacy_390`	Fermi and Kepler
`legacy_340`	Tesla

Unknown device IDs default to stable.

The device matching is based on the PCI device ID rather than the GPU name. This avoids relying on marketing names and keeps the detection independent of lspci output or other runtime tools.

How it integrates with NixOS #

The module uses the existing NixOS NVIDIA package set:

config.boot.kernelPackages.nvidiaPackages

The selected package is then assigned through:

hardware.nvidia.package

using lib.mkDefault, so it can still be overridden by the host configuration when necessary.

For example:

{
  hardware.nvidia.package =
    lib.mkForce config.boot.kernelPackages.nvidiaPackages.stable;
}

This is intentional. The module provides a default based on hardware detection, but does not prevent a machine from explicitly choosing a different driver.

Facter dependency #

The module expects the nix-facter report to be available through:

config.hardware.facter.report

and reads NVIDIA PCI devices from:

config.hardware.facter.report.hardware.pci

A device is considered an NVIDIA display controller when:

the PCI vendor is 0x10de
the PCI class starts with 0x03

This covers both VGA-compatible controllers and 3D controllers.

Why this exists #

Nixpkgs already provides the NVIDIA driver packages and the hardware.nvidia module. The missing piece is knowing which legacy branch is appropriate for a given GPU.

This module keeps that logic in one place and makes it possible for a generic NixOS hardware configuration to automatically select a compatible NVIDIA driver.

The intended workflow is:

nixos-facter
      │
      ▼
hardware.facter.report
      │
      ▼
NVIDIA PCI device ID
      │
      ▼
driver family
      │
      ▼
nvidiaPackages.<family>
      │
      ▼
hardware.nvidia

Overrides #

Automatic detection is only a default.

If the selected driver is not appropriate for a particular system, the normal NixOS NVIDIA configuration can still be used to override it.

The module can also be disabled explicitly through:

{
  hardware.facter.detected.graphics.nvidia.enable = false;
}

This leaves NVIDIA configuration entirely to the host.

Scope #

This module intentionally does not:

detect or configure non-NVIDIA GPUs
configure NVIDIA hardware beyond the existing NixOS module
select kernels
configure firmware
modify Xorg or Wayland beyond the required NVIDIA settings
provide a custom NVIDIA driver package
replace nixpkgs' NVIDIA support

It is just the detection and selection layer on top of what NixOS already provides.

Status #

Early development.

The supported PCI ID ranges are maintained against NVIDIA's legacy driver support information. New GPU generations should naturally fall back to stable until a specific legacy branch needs to be added.