diff --git a/common/hw-gfx-gma-config_helpers.ads b/common/hw-gfx-gma-config_helpers.ads
new file mode 100644
index 0000000..b56e1b1
--- /dev/null
+++ b/common/hw-gfx-gma-config_helpers.ads
@@ -0,0 +1,45 @@
+--
+-- Copyright (C) 2015-2016 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.
+--
+
+with HW;
+
+private package HW.GFX.GMA.Config_Helpers
+is
+
+   function To_PCH_Port (Port : Active_Port_Type) return PCH_Port;
+
+   function To_Display_Type (Port : Active_Port_Type) return Display_Type;
+
+   procedure Fill_Port_Config
+     (Port_Cfg :    out Port_Config;
+      Pipe     : in     Pipe_Index;
+      Port     : in     Port_Type;
+      Mode     : in     Mode_Type;
+      Success  :    out Boolean);
+
+   ----------------------------------------------------------------------------
+
+   use type HW.Pos32;
+   function Validate_Config
+     (Framebuffer : Framebuffer_Type;
+      Port_Cfg    : Port_Config;
+      Pipe        : Pipe_Index)
+      return Boolean
+   with
+      Post =>
+        (if Validate_Config'Result then
+            Framebuffer.Width <= Pos32 (Port_Cfg.Mode.H_Visible) and
+            Framebuffer.Height <= Pos32 (Port_Cfg.Mode.V_Visible));
+
+end HW.GFX.GMA.Config_Helpers;