--- /dev/null
+;------------------------------------------------------------------------------\r
+;\r
+; Copyright (c) 2006, Intel Corporation\r
+; All rights reserved. This program and the accompanying materials\r
+; are licensed and made available under the terms and conditions of the BSD License\r
+; which accompanies this distribution. The full text of the license may be found at\r
+; http://opensource.org/licenses/bsd-license.php\r
+;\r
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
+;\r
+; Module Name:\r
+;\r
+; WriteMsr64.Asm\r
+;\r
+; Abstract:\r
+;\r
+; AsmWriteMsr64 function\r
+;\r
+; Notes:\r
+;\r
+;------------------------------------------------------------------------------\r
+\r
+ .code\r
+\r
+;------------------------------------------------------------------------------\r
+; UINT64\r
+; EFIAPI\r
+; AsmWriteMsr64 (\r
+; IN UINT32 Index,\r
+; IN UINT64 Value\r
+; );\r
+;------------------------------------------------------------------------------\r
+AsmWriteMsr64 PROC\r
+ mov rax, rdx ; meanwhile, rax <- return value\r
+ shr rdx, 20h ; edx:eax contains the value to write\r
+ wrmsr\r
+ ret\r
+AsmWriteMsr64 ENDP\r
+\r
+ END\r