Save segment registers on stack in case the thunk code assembly calls CF9 soft reset...

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

diff --git a/MdePkg/Library/BaseLib/Ia32/Mwait.c b/MdePkg/Library/BaseLib/Ia32/Mwait.c
index b6ad777939791c92fb7af018021ba14f53c9b120..8e6993725efdc74856cf92f23ad685a2225a01f4 100644 (file)
--- a/MdePkg/Library/BaseLib/Ia32/Mwait.c
+++ b/MdePkg/Library/BaseLib/Ia32/Mwait.c
@@ -1,7 +1,7 @@
 /** @file\r
   AsmMwait function\r
 \r
-  Copyright (c) 2006, Intel Corporation<BR>\r
+  Copyright (c) 2006 - 2008, Intel Corporation<BR>\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
@@ -12,8 +12,20 @@
 \r
 **/\r
 \r
-#if _MSC_EXTENSIONS\r
+/**\r
+  Executes an MWAIT instruction.\r
 \r
+  Executes an MWAIT instruction with the register state specified by Eax and\r
+  Ecx. Returns Eax. This function is only available on IA-32 and x64.\r
+\r
+  @param  RegisterEax The value to load into EAX or RAX before executing the MONITOR\r
+                      instruction.\r
+  @param  RegisterEcx The value to load into ECX or RCX before executing the MONITOR\r
+                      instruction.\r
+\r
+  @return RegisterEax\r
+\r
+**/\r
 UINTN\r
 EFIAPI\r
 AsmMwait (\r
@@ -30,4 +42,3 @@ AsmMwait (
   }\r
 }\r
 \r
-#endif\r