added robust iso

iso/iso_plymouth-theme.nix

@@ -0,0 +1,44 @@
+{ pkgs, lib }:
+
+pkgs.stdenv.mkDerivation {
+  pname = "sovran-plymouth-theme";
+  version = "1.0";
+
+  src = ./.;
+
+  installPhase = ''
+    mkdir -p $out/share/plymouth/themes/sovran
+    cp ${./assets/splash-logo.png} $out/share/plymouth/themes/sovran/logo.png
+
+    cat > $out/share/plymouth/themes/sovran/sovran.plymouth <<'EOF'
+[Plymouth Theme]
+Name=Sovran Systems
+Description=Sovran Systems Splash
+ModuleName=script
+
+[script]
+ImageDir=/share/plymouth/themes/sovran
+ScriptFile=/share/plymouth/themes/sovran/sovran.script
+EOF
+
+    cat > $out/share/plymouth/themes/sovran/sovran.script <<'EOF'
+# Background color: #CFFFD7 (RGB 207,255,215)
+bg_r = 207/255.0
+bg_g = 255/255.0
+bg_b = 215/255.0
+
+Window.SetBackgroundTopColor (bg_r, bg_g, bg_b);
+Window.SetBackgroundBottomColor (bg_r, bg_g, bg_b);
+
+logo = Image("logo.png");
+logo_sprite = Sprite(logo);
+logo_sprite.SetX((Window.GetWidth() - logo.GetWidth()) / 2);
+logo_sprite.SetY((Window.GetHeight() - logo.GetHeight()) / 2);
+
+spinner = Sprite();
+spinner.SetImage(Spinner());
+spinner.SetX((Window.GetWidth() - spinner.GetImage().GetWidth()) / 2);
+spinner.SetY((Window.GetHeight() + logo.GetHeight()) / 2 + 20);
+EOF
+  '';
+}