Init

nixos/plymouth/default.nix

@@ -0,0 +1,36 @@
+{ pkgs, ... }:
+let
+  mikuTheme = pkgs.stdenv.mkDerivation {
+    name = "plymouth-theme-miku";
+    src = ./miku;
+    installPhase = ''
+      mkdir -p $out/share/plymouth/themes/miku/frames
+      cp miku.plymouth $out/share/plymouth/themes/miku/
+      cp miku.script $out/share/plymouth/themes/miku/
+      cp images/frames/*.png $out/share/plymouth/themes/miku/frames/
+    '';
+  };
+in
+{
+  boot = {
+    plymouth = {
+      enable = true;
+      theme = "miku";
+      themePackages = [
+        mikuTheme
+      ];
+    };
+
+    # Enable "Silent boot"
+    consoleLogLevel = 3;
+    initrd.verbose = false;
+    kernelParams = [
+      "quiet"
+      "splash"
+      "boot.shell_on_fail"
+      "udev.log_priority=3"
+      "rd.systemd.show_status=auto"
+    ];
+    loader.timeout = 0;
+  };
+}

nixos/plymouth/miku/miku.plymouth

@@ -0,0 +1,8 @@
+[Plymouth Theme]
+Name=Miku
+Description=Hatsune Miku Dancing
+ModuleName=Script
+
+[script]
+ImageDir=/usr/share/plymouth/themes/miku 
+ScriptFile=/usr/share/plymouth/themes/miku/miku.script

nixos/plymouth/miku/miku.script

@@ -0,0 +1,30 @@
+# Screen dimensions
+screen_width = Window.GetWidth();
+screen_height = Window.GetHeight();
+
+# Load frames
+frame_count = 53;
+frames = [];
+for (i = 0; i < frame_count; i++) {
+    num = String(i);
+    if (i < 10) num = "000" + num;
+    else if (i < 100) num = "00" + num;
+	else num = "0" + num;
+    frames[i] = Image("frames/frame_" + num + ".png");
+}
+
+# Position centered
+x = (screen_width - 498) / 2;
+y = (screen_height - 498) / 2;
+
+# Animation state
+current_frame = 0;
+
+fun refresh_callback() {
+    sprite = Sprite(frames[current_frame]);
+    sprite.SetX(x);
+    sprite.SetY(y);
+    current_frame = (current_frame + 1) % frame_count;
+}
+
+Plymouth.SetRefreshFunction(refresh_callback);