nixpkgs/nixos/modules/hardware/device-tree.nix
Kai Wohlfahrt dd0a951279 nixos/hardware.deviceTree: new module
Add support for custom device-tree files, and applying overlays to them.
This is useful for supporting non-discoverable hardware, such as sensors
attached to GPIO pins on a Raspberry Pi.
2019-08-07 13:51:22 +01:00

57 lines
1.7 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.hardware.deviceTree;
in {
options = {
hardware.deviceTree = {
enable = mkOption {
default = pkgs.stdenv.hostPlatform.platform.kernelDTB or false;
type = types.bool;
description = ''
Build device tree files. These are used to describe the
non-discoverable hardware of a system.
'';
};
base = mkOption {
default = "${config.boot.kernelPackages.kernel}/dtbs";
defaultText = "\${config.boot.kernelPackages.kernel}/dtbs";
example = literalExample "pkgs.deviceTree.raspberryPiDtbs";
type = types.nullOr types.path;
description = ''
The package containing the base device-tree (.dtb) to boot. Contains
device trees bundled with the Linux kernel by default.
'';
};
overlays = mkOption {
default = [];
example = literalExample
"[\"\${pkgs.deviceTree.raspberryPiOverlays}/w1-gpio.dtbo\"]";
type = types.listOf types.path;
description = ''
A path containing device tree overlays (.dtbo) to be applied to all
base device-trees.
'';
};
package = mkOption {
default = null;
type = types.nullOr types.path;
description = ''
A path containing device tree overlays (.dtbo) to be applied to all
base device-trees. Overrides `base` and `overlays`.
'';
};
};
};
config = mkIf (cfg.enable) {
hardware.deviceTree.package = if (cfg.overlays != [])
then pkgs.deviceTree.applyOverlays cfg.base cfg.overlays else cfg.base;
};
}