diff --git a/common/g45/hw-gfx-gma-gmch-hdmi.ads b/common/g45/hw-gfx-gma-gmch-hdmi.ads
new file mode 100644
index 0000000..3905f0c
--- /dev/null
+++ b/common/g45/hw-gfx-gma-gmch-hdmi.ads
@@ -0,0 +1,26 @@
+--
+-- Copyright (C) 2016 secunet Security Networks AG
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 2 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+
+package HW.GFX.GMA.GMCH.HDMI
+is
+
+   procedure On (Port_Cfg : in Port_Config;
+                 Pipe     : in Pipe_Index)
+   with
+      Pre => Port_Cfg.Port in GMCH_HDMI_Port;
+
+   procedure Off (Port : GMCH_HDMI_Port);
+   procedure All_Off;
+
+end HW.GFX.GMA.GMCH.HDMI;