Fix the issue that the high 16-bit of EAX may contain invalid data, which cause bad stack pointer, the change will ensure the high 16-bit of EAX is cleared.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11047 6f19259b-4bc3-4df7-8a09-765794883524

4 files changed, 8 insertions, 8 deletions

diff --git a/MdePkg/Library/BaseLib/Ia32/Thunk16.S b/MdePkg/Library/BaseLib/Ia32/Thunk16.S
index 75d857501a..44aea1a5ef 100644
--- a/MdePkg/Library/BaseLib/Ia32/Thunk16.S
+++ b/MdePkg/Library/BaseLib/Ia32/Thunk16.S
@@ -1,6 +1,6 @@
 #------------------------------------------------------------------------------

 #

-# Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>

+# Copyright (c) 2006 - 2010, 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

@@ -55,7 +55,7 @@ ASM_PFX(ThunkAttr): .space  4
     orb     $2, %al

     outb    %al, $0x92                  # deactivate A20M#

 2:

-    movl    %ss, %eax

+    movw    %ss, %ax

     .byte   0x67, 0x66, 0x8d, 0x6c, 0x24, 0x34, 0x66

     mov     %ebp, 0xffffffd8(%esi)

     mov     0xfffffff8(%esi), %ebx

diff --git a/MdePkg/Library/BaseLib/Ia32/Thunk16.asm b/MdePkg/Library/BaseLib/Ia32/Thunk16.asm
index a7560a247f..31f9254ad5 100644
--- a/MdePkg/Library/BaseLib/Ia32/Thunk16.asm
+++ b/MdePkg/Library/BaseLib/Ia32/Thunk16.asm
@@ -3,7 +3,7 @@
 

 ;------------------------------------------------------------------------------

 ;

-; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>

+; Copyright (c) 2006 - 2010, 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

@@ -109,7 +109,7 @@ _ThunkAttr  DD      ?
     or      al, 2

     out     92h, al                     ; deactivate A20M#

 @2:

-    mov     eax, ss

+    mov     ax, ss

     DB      67h

     lea     bp, [esp + sizeof (IA32_REGS)]

     ;

diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.S b/MdePkg/Library/BaseLib/X64/Thunk16.S
index fa9b3d6035..049ec86355 100644
--- a/MdePkg/Library/BaseLib/X64/Thunk16.S
+++ b/MdePkg/Library/BaseLib/X64/Thunk16.S
@@ -1,6 +1,6 @@
 #------------------------------------------------------------------------------

 #

-# Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>

+# Copyright (c) 2006 - 2010, 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

@@ -104,7 +104,7 @@ L_1:
     orb     $2,%al

     outb    %al, $0x92                   # deactivate A20M#

 L_2: 

-    movl    %ss,%eax

+    movw    %ss,%ax

     lea     IA32_REGS_SIZE(%esp), %bp

     #

     # rsi in the following 2 instructions is indeed bp in 16-bit code

diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.asm b/MdePkg/Library/BaseLib/X64/Thunk16.asm
index 459966a43f..829df1c2a0 100644
--- a/MdePkg/Library/BaseLib/X64/Thunk16.asm
+++ b/MdePkg/Library/BaseLib/X64/Thunk16.asm
@@ -3,7 +3,7 @@
 

 ;------------------------------------------------------------------------------

 ;

-; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>

+; Copyright (c) 2006 - 2010, 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

@@ -105,7 +105,7 @@ _ThunkAttr  DD      ?
     or      al, 2

     out     92h, al                     ; deactivate A20M#

 @2:

-    mov     eax, ss

+    mov     ax, ss

     lea     bp, [esp + sizeof (IA32_REGS)]

     ;

     ; rsi in the following 2 instructions is indeed bp in 16-bit code