nixos/initrd: add extraFirmwarePaths option (#391166)

nixos/modules/system/boot/stage-1.nix

@@ -19,6 +19,7 @@ let
     kernel = config.system.modulesTree;
     firmware = config.hardware.firmware;
     allowMissing = false;
+    inherit (config.boot.initrd) extraFirmwarePaths;
   };
 
 
@@ -484,6 +485,14 @@ in
       '';
     };
 
+    boot.initrd.extraFirmwarePaths = mkOption {
+      default = [ ];
+      type = types.listOf types.str;
+      description = ''
+        Other firmware files (relative to `"''${config.hardware.firmware}/lib/firmware"`) to include in the final initrd we are building.
+      '';
+    };
+
     boot.initrd.checkJournalingFS = mkOption {
       default = true;
       type = types.bool;

nixos/modules/system/boot/systemd/initrd.nix

@@ -105,6 +105,7 @@ let
     kernel = config.system.modulesTree;
     firmware = config.hardware.firmware;
     allowMissing = false;
+    inherit (config.boot.initrd) extraFirmwarePaths;
   };
 
   initrdBinEnv = pkgs.buildEnv {

pkgs/build-support/kernel/modules-closure.nix

@@ -11,6 +11,7 @@
   rootModules,
   kmod,
   allowMissing ? false,
+  extraFirmwarePaths ? [ ],
 }:
 
 stdenvNoCC.mkDerivation {
@@ -25,6 +26,7 @@ stdenvNoCC.mkDerivation {
     firmware
     rootModules
     allowMissing
+    extraFirmwarePaths
     ;
   allowedReferences = [ "out" ];
 }

pkgs/build-support/kernel/modules-closure.sh

@@ -87,6 +87,15 @@ for module in $(< ~-/closure); do
     done || :
 done
 
+for path in $extraFirmwarePaths; do
+    mkdir -p $(dirname $out/lib/firmware/$path)
+    for name in "$path" "$path.xz" "$path.zst" ""; do
+        if cp -v --parents --no-preserve=mode lib/firmware/$name "$out" 2>/dev/null; then
+            break
+        fi
+    done
+done
+
 if test -e lib/firmware/edid ; then
     echo "lib/firmware/edid found, copying."
     mkdir -p "$out/lib/firmware"

pkgs/top-level/all-packages.nix

@@ -709,9 +709,9 @@ with pkgs;
 
   compressFirmwareZstd = callPackage ../build-support/kernel/compress-firmware.nix { type = "zstd"; };
 
-  makeModulesClosure = { kernel, firmware, rootModules, allowMissing ? false }:
+  makeModulesClosure = { kernel, firmware, rootModules, allowMissing ? false, extraFirmwarePaths ? [ ] }:
     callPackage ../build-support/kernel/modules-closure.nix {
-      inherit kernel firmware rootModules allowMissing;
+      inherit kernel firmware rootModules allowMissing extraFirmwarePaths;
     };
 
   mkBinaryCache = callPackage ../build-support/binary-cache { };