diff --git a/common/g45/hw-gfx-gma-gmch.ads b/common/g45/hw-gfx-gma-gmch.ads
new file mode 100644
index 0000000..0e7832c
--- /dev/null
+++ b/common/g45/hw-gfx-gma-gmch.ads
@@ -0,0 +1,13 @@
+with HW.GFX.GMA.Config;
+
+private package HW.GFX.GMA.GMCH is
+
+   GMCH_PORT_PIPE_SELECT_SHIFT : constant := 30;
+   GMCH_PORT_PIPE_SELECT_MASK  : constant := 1 * 2 ** 30;
+   type GMCH_PORT_PIPE_SELECT_Array is array (Pipe_Index) of Word32;
+   GMCH_PORT_PIPE_SELECT       : constant GMCH_PORT_PIPE_SELECT_Array :=
+     (Primary   => 0 * 2 ** GMCH_PORT_PIPE_SELECT_SHIFT,
+      Secondary => 1 * 2 ** GMCH_PORT_PIPE_SELECT_SHIFT,
+      Tertiary  => 0);
+
+end HW.GFX.GMA.GMCH;