1 files changed, 29 insertions, 0 deletions
diff --git a/mp/src/public/tier0/IOCTLCodes.h b/mp/src/public/tier0/IOCTLCodes.h
new file mode 100644
index 00000000..52dfe560
--- /dev/null
+++ b/mp/src/public/tier0/IOCTLCodes.h
@@ -0,0 +1,29 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//
+//=============================================================================//
+#ifndef IOCTLCODES_H
+#define IOCTLCODES_H
+#pragma once
+
+// Define the IOCTL codes we will use.  The IOCTL code contains a command
+// identifier, plus other information about the device, the type of access
+// with which the file must have been opened, and the type of buffering.
+
+// Device type           -- in the "User Defined" range."
+#define DEVICE_FILE_TYPE 40000
+
+
+// The IOCTL function codes from 0x800 to 0xFFF are for customer use.
+
+#define IOCTL_WRITE_MSR \
+    CTL_CODE( DEVICE_FILE_TYPE, 0x900, METHOD_BUFFERED, FILE_READ_ACCESS )
+
+#define IOCTL_READ_MSR \
+    CTL_CODE( DEVICE_FILE_TYPE, 0x901, METHOD_BUFFERED, FILE_READ_ACCESS )
+
+
+#endif IOCTLCODES_H