1 files changed, 57 insertions, 1 deletions
diff --git a/src/mainboard/lenovo/x201/acpi/platform.asl b/src/mainboard/lenovo/x201/acpi/platform.asl
index 1a3279d383..b03f45f8f0 100644
--- a/src/mainboard/lenovo/x201/acpi/platform.asl
+++ b/src/mainboard/lenovo/x201/acpi/platform.asl
@@ -42,6 +42,62 @@ Scope(\_SB)
 
 		/* TRAP(71) */ /* TODO */
 
-		\GOS()
+		/* Determine the Operating System and save the value in OSYS.
+		 * We have to do this in order to be able to work around
+		 * certain windows bugs.
+		 *
+		 *    OSYS value | Operating System
+		 *    -----------+------------------
+		 *       2000    | Windows 2000
+		 *       2001    | Windows XP(+SP1)
+		 *       2002    | Windows XP SP2
+		 *       2006    | Windows Vista
+		 *       ????    | Windows 7
+		 */
+
+		/* Let's assume we're running at least Windows 2000 */
+		Store (2000, OSYS)
+
+		If (CondRefOf(_OSI)) {
+			If (_OSI("Windows 2001")) {
+				Store (2001, OSYS)
+			}
+
+			If (_OSI("Windows 2001 SP1")) {
+				Store (2001, OSYS)
+			}
+
+			If (_OSI("Windows 2001 SP2")) {
+				Store (2002, OSYS)
+			}
+
+			If (_OSI("Windows 2001.1")) {
+				Store (2001, OSYS)
+			}
+
+			If (_OSI("Windows 2001.1 SP1")) {
+				Store (2001, OSYS)
+			}
+
+			If (_OSI("Windows 2006")) {
+				Store (2006, OSYS)
+			}
+
+			If (_OSI("Windows 2006.1")) {
+				Store (2006, OSYS)
+			}
+
+			If (_OSI("Windows 2006 SP1")) {
+				Store (2006, OSYS)
+			}
+
+			If (_OSI("Windows 2009")) {
+				Store (2009, OSYS)
+			}
+
+			If (_OSI("Windows 2012")) {
+				Store (2012, OSYS)
+			}
+		}
 	}
 }