diff options
Diffstat (limited to 'nixos/modules/hardware/device-tree.nix')
-rw-r--r-- | nixos/modules/hardware/device-tree.nix | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/nixos/modules/hardware/device-tree.nix b/nixos/modules/hardware/device-tree.nix new file mode 100644 index 00000000000..be67116ad50 --- /dev/null +++ b/nixos/modules/hardware/device-tree.nix @@ -0,0 +1,205 @@ +{ config, lib, pkgs, ... }: + +with lib; + +let + cfg = config.hardware.deviceTree; + + overlayType = types.submodule { + options = { + name = mkOption { + type = types.str; + description = '' + Name of this overlay + ''; + }; + + dtsFile = mkOption { + type = types.nullOr types.path; + description = '' + Path to .dts overlay file, overlay is applied to + each .dtb file matching "compatible" of the overlay. + ''; + default = null; + example = literalExpression "./dts/overlays.dts"; + }; + + dtsText = mkOption { + type = types.nullOr types.str; + default = null; + description = '' + Literal DTS contents, overlay is applied to + each .dtb file matching "compatible" of the overlay. + ''; + example = '' + /dts-v1/; + /plugin/; + / { + compatible = "raspberrypi"; + fragment@0 { + target-path = "/soc"; + __overlay__ { + pps { + compatible = "pps-gpio"; + status = "okay"; + }; + }; + }; + }; + ''; + }; + + dtboFile = mkOption { + type = types.nullOr types.path; + default = null; + description = '' + Path to .dtbo compiled overlay file. + ''; + }; + }; + }; + + # this requires kernel package + dtbsWithSymbols = pkgs.stdenv.mkDerivation { + name = "dtbs-with-symbols"; + inherit (cfg.kernelPackage) src nativeBuildInputs depsBuildBuild; + patches = map (patch: patch.patch) cfg.kernelPackage.kernelPatches; + buildPhase = '' + patchShebangs scripts/* + substituteInPlace scripts/Makefile.lib \ + --replace 'DTC_FLAGS += $(DTC_FLAGS_$(basetarget))' 'DTC_FLAGS += $(DTC_FLAGS_$(basetarget)) -@' + make ${pkgs.stdenv.hostPlatform.linux-kernel.baseConfig} ARCH="${pkgs.stdenv.hostPlatform.linuxArch}" + make dtbs ARCH="${pkgs.stdenv.hostPlatform.linuxArch}" + ''; + installPhase = '' + make dtbs_install INSTALL_DTBS_PATH=$out/dtbs ARCH="${pkgs.stdenv.hostPlatform.linuxArch}" + ''; + }; + + filterDTBs = src: if isNull cfg.filter + then "${src}/dtbs" + else + pkgs.runCommand "dtbs-filtered" {} '' + mkdir -p $out + cd ${src}/dtbs + find . -type f -name '${cfg.filter}' -print0 \ + | xargs -0 cp -v --no-preserve=mode --target-directory $out --parents + ''; + + # Compile single Device Tree overlay source + # file (.dts) into its compiled variant (.dtbo) + compileDTS = name: f: pkgs.callPackage({ dtc }: pkgs.stdenv.mkDerivation { + name = "${name}-dtbo"; + + nativeBuildInputs = [ dtc ]; + + buildCommand = '' + dtc -I dts ${f} -O dtb -@ -o $out + ''; + }) {}; + + # Fill in `dtboFile` for each overlay if not set already. + # Existence of one of these is guarded by assertion below + withDTBOs = xs: flip map xs (o: o // { dtboFile = + if isNull o.dtboFile then + if !isNull o.dtsFile then compileDTS o.name o.dtsFile + else compileDTS o.name (pkgs.writeText "dts" o.dtsText) + else o.dtboFile; } ); + +in +{ + imports = [ + (mkRemovedOptionModule [ "hardware" "deviceTree" "base" ] "Use hardware.deviceTree.kernelPackage instead") + ]; + + options = { + hardware.deviceTree = { + enable = mkOption { + default = pkgs.stdenv.hostPlatform.linux-kernel.DTB or false; + type = types.bool; + description = '' + Build device tree files. These are used to describe the + non-discoverable hardware of a system. + ''; + }; + + kernelPackage = mkOption { + default = config.boot.kernelPackages.kernel; + defaultText = literalExpression "config.boot.kernelPackages.kernel"; + example = literalExpression "pkgs.linux_latest"; + type = types.path; + description = '' + Kernel package containing the base device-tree (.dtb) to boot. Uses + device trees bundled with the Linux kernel by default. + ''; + }; + + name = mkOption { + default = null; + example = "some-dtb.dtb"; + type = types.nullOr types.str; + description = '' + The name of an explicit dtb to be loaded, relative to the dtb base. + Useful in extlinux scenarios if the bootloader doesn't pick the + right .dtb file from FDTDIR. + ''; + }; + + filter = mkOption { + type = types.nullOr types.str; + default = null; + example = "*rpi*.dtb"; + description = '' + Only include .dtb files matching glob expression. + ''; + }; + + overlays = mkOption { + default = []; + example = literalExpression '' + [ + { name = "pps"; dtsFile = ./dts/pps.dts; } + { name = "spi"; + dtsText = "..."; + } + { name = "precompiled"; dtboFile = ./dtbos/example.dtbo; } + ] + ''; + type = types.listOf (types.coercedTo types.path (path: { + name = baseNameOf path; + dtboFile = path; + }) overlayType); + description = '' + List of overlays to apply to base device-tree (.dtb) files. + ''; + }; + + package = mkOption { + default = null; + type = types.nullOr types.path; + internal = true; + description = '' + A path containing the result of applying `overlays` to `kernelPackage`. + ''; + }; + }; + }; + + config = mkIf (cfg.enable) { + + assertions = let + invalidOverlay = o: isNull o.dtsFile && isNull o.dtsText && isNull o.dtboFile; + in lib.singleton { + assertion = lib.all (o: !invalidOverlay o) cfg.overlays; + message = '' + deviceTree overlay needs one of dtsFile, dtsText or dtboFile set. + Offending overlay(s): + ${toString (map (o: o.name) (builtins.filter invalidOverlay cfg.overlays))} + ''; + }; + + hardware.deviceTree.package = if (cfg.overlays != []) + then pkgs.deviceTree.applyOverlays (filterDTBs dtbsWithSymbols) (withDTBOs cfg.overlays) + else (filterDTBs cfg.kernelPackage); + }; +} |