optionally build nvramtool, put it and the .layout files in the initramfs

src/platform/kgpe/default.nix

@@ -18,6 +18,13 @@ in
         '';
       });
 
+    userspace = prev.userspace.overrideAttrs (a: {
+      postInstall = (a.postInstall or "") + ''
+        cp ${final.coreboot.src}/mainboard/asus/kgpe-d16/cmos.layout $out/etc/
+        cp ${final.coreboot.src}/mainboard/asus/kgpe-d16/cmos.default $out/etc/
+      '';
+    });
+
     coreboot = let
       # does include spectre mitigations (performance hit)
       #linux-firmware = final.nixpkgsOnBuildForBuild.linux-firmware;

src/userspace/default.nix

@@ -15,11 +15,14 @@
 , withLvm ? false
 , withCryptsetup ? false
 , withKexec ? false
+, withNvramTool ? false # nixpkgsOnBuildForHost.stdenv.hostPlatform.isx86
 }:
 
 let
   inherit (nixpkgsOnBuildForHost.pkgsStatic) stdenv busybox signify lvm2 cryptsetup kexec-tools findutils cpio;
-
+  nvramtool = nixpkgsOnBuildForHost.pkgsStatic.nvramtool.overrideAttrs(a: {
+    NIX_CFLAGS_COMPILE = "-D__GLIBC__";
+  });
 in stdenv.mkDerivation {
   name = "ownerboot-initramfs-userspace";
   dontUnpack = true;
@@ -48,6 +51,8 @@ in stdenv.mkDerivation {
     cp ${cryptsetup}/bin/cryptsetup $out/bin/
   '' + lib.optionalString withKexec ''
     cp ${kexec-tools}/bin/kexec $out/bin/
+  '' + lib.optionalString withNvramTool ''
+    cp ${nvramtool}/bin/nvramtool $out/bin/
   '' + ''
     runHook postInstall
   '';