MdePkg/BaseLib: Support IA32 processors without CLFLUSH

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / WriteMsr64.c

diff --git a/MdePkg/Library/BaseLib/Ia32/WriteMsr64.c b/MdePkg/Library/BaseLib/Ia32/WriteMsr64.c
index 06cf910c48fbf80d3e141bd652a16e47de9aa33b..2f22f49fbda0f729ed8d78c2480473864f1433db 100644 (file)
--- a/MdePkg/Library/BaseLib/Ia32/WriteMsr64.c
+++ b/MdePkg/Library/BaseLib/Ia32/WriteMsr64.c
@@ -1,22 +1,37 @@
 /** @file\r
   AsmWriteMsr64 function\r
 \r
-  Copyright (c) 2006 - 2007, Intel Corporation<BR>\r
-  All rights reserved. This program and the accompanying materials\r
+  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>\r
+  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
+  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
 **/\r
 \r
-//\r
-// Include common header file for this module.\r
-//\r
 \r
 \r
+\r
+/**\r
+  Writes a 64-bit value to a Machine Specific Register(MSR), and returns the\r
+  value.\r
+\r
+  Writes the 64-bit value specified by Value to the MSR specified by Index. The\r
+  64-bit value written to the MSR is returned. No parameter checking is\r
+  performed on Index or Value, and some of these may cause CPU exceptions. The\r
+  caller must either guarantee that Index and Value are valid, or the caller\r
+  must establish proper exception handlers. This function is only available on\r
+  IA-32 and x64.\r
+\r
+  @param  Index The 32-bit MSR index to write.\r
+  @param  Value The 64-bit value to write to the MSR.\r
+\r
+  @return Value\r
+\r
+**/\r
 UINT64\r
 EFIAPI\r
 AsmWriteMsr64 (\r