2 files changed, 8 insertions, 2 deletions
diff --git a/UefiCpuPkg/CpuDxe/Ia32/CpuAsm.S b/UefiCpuPkg/CpuDxe/Ia32/CpuAsm.S
index d3e1dee..38f46ab 100644
--- a/UefiCpuPkg/CpuDxe/Ia32/CpuAsm.S
+++ b/UefiCpuPkg/CpuDxe/Ia32/CpuAsm.S
@@ -1,6 +1,6 @@
 #------------------------------------------------------------------------------
 #*
-#*   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
+#*   Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
 #*   This program and the accompanying materials
 #*   are licensed and made available under the terms and conditions of the BSD License
 #*   which accompanies this distribution.  The full text of the license may be found at
@@ -274,6 +274,9 @@ ErrorCodeAndVectorOnStack:
     movl    %esp, %edi
     .byte      0x0f, 0x0ae, 0x07 #fxsave [edi]
 
+#; UEFI calling convention for IA32 requires that Direction flag in EFLAGs is clear
+    cld
+
 #; UINT32  ExceptionData;
     pushl   8(%ebp)
 
diff --git a/UefiCpuPkg/CpuDxe/X64/CpuAsm.S b/UefiCpuPkg/CpuDxe/X64/CpuAsm.S
index 8f19132..f1481d8 100644
--- a/UefiCpuPkg/CpuDxe/X64/CpuAsm.S
+++ b/UefiCpuPkg/CpuDxe/X64/CpuAsm.S
@@ -2,7 +2,7 @@
 
 #------------------------------------------------------------------------------
 #*
-#*   Copyright (c) 2008 - 2010, Intel Corporation. All rights reserved.<BR>
+#*   Copyright (c) 2008 - 2011, Intel Corporation. All rights reserved.<BR>
 #*   This program and the accompanying materials
 #*   are licensed and made available under the terms and conditions of the BSD License
 #*   which accompanies this distribution.  The full text of the license may be found at
@@ -234,6 +234,9 @@ CommonInterruptEntry_al_0000:
     movq    %rsp, %rdi
     .byte 0x0f, 0x0ae, 0x07 #fxsave [rdi]
 
+#; UEFI calling convention for x64 requires that Direction flag in EFLAGs is clear
+    cld
+
 #; UINT32  ExceptionData;
     pushq   16(%rbp)