Current Thunk16.asm implementation clears reserved bits, which does not follow IA32 SDM. Now the fix is to only clear PAE and PSE bit of CR4 for real mode.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@14037 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 0555cf1bfd..8356c5a1c7 100644
--- a/MdePkg/Library/BaseLib/Ia32/Thunk16.S
+++ b/MdePkg/Library/BaseLib/Ia32/Thunk16.S
@@ -1,6 +1,6 @@
 #------------------------------------------------------------------------------

 #

-# Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>

+# Copyright (c) 2006 - 2013, 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

@@ -175,7 +175,7 @@ ASM_PFX(InternalAsmThunk16):
     andl    $0x7ffffffe, %eax           # clear PE, PG bits

     movl    %cr4, %ebp

     mov     %ebp, 0xfffffff1(%edx)

-    andl    $0x300, %ebp                # clear all but PCE and OSFXSR bits

+    andl    $0xffffffcf, %ebp           # clear PAE, PSE bits

     pushl   $0x10

     pop     %ecx                        # ecx <- selector for data segments

     lgdtl   0x20(%edx)

diff --git a/MdePkg/Library/BaseLib/Ia32/Thunk16.asm b/MdePkg/Library/BaseLib/Ia32/Thunk16.asm
index 6df0a4a46a..3e84aedf3d 100644
--- a/MdePkg/Library/BaseLib/Ia32/Thunk16.asm
+++ b/MdePkg/Library/BaseLib/Ia32/Thunk16.asm
@@ -3,7 +3,7 @@
 

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

 ;

-; Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>

+; Copyright (c) 2006 - 2013, 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

@@ -237,7 +237,7 @@ InternalAsmThunk16  PROC    USES    ebp ebx esi edi ds  es  fs  gs
     and     eax, 7ffffffeh              ; clear PE, PG bits

     mov     ebp, cr4

     mov     [edx + (SavedCr4 - SavedCr0)], ebp

-    and     ebp, 300h                   ; clear all but PCE and OSFXSR bits

+    and     ebp, NOT 30h                ; clear PAE, PSE bits

     push    10h

     pop     ecx                         ; ecx <- selector for data segments

     lgdt    fword ptr [edx + (_16Gdtr - SavedCr0)]

diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.S b/MdePkg/Library/BaseLib/X64/Thunk16.S
index d037a71043..a521aff31b 100644
--- a/MdePkg/Library/BaseLib/X64/Thunk16.S
+++ b/MdePkg/Library/BaseLib/X64/Thunk16.S
@@ -1,6 +1,6 @@
 #------------------------------------------------------------------------------

 #

-# Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>

+# Copyright (c) 2006 - 2013, 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

@@ -295,7 +295,7 @@ ASM_PFX(InternalAsmThunk16):
     andl    $0x7ffffffe,%eax            # clear PE, PG bits

     movq    %cr4, %rbp

     movl    %ebp, (%rcx)                # save CR4 in SavedCr4

-    andl    $0x300,%ebp                 # clear all but PCE and OSFXSR bits

+    andl    $0xffffffcf,%ebp            # clear PAE, PSE bits

     movl    %r8d, %esi                  # esi <- 16-bit stack segment

     .byte      0x6a, DATA32

     popq    %rdx

diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.asm b/MdePkg/Library/BaseLib/X64/Thunk16.asm
index 8b208fdb58..01051341f6 100644
--- a/MdePkg/Library/BaseLib/X64/Thunk16.asm
+++ b/MdePkg/Library/BaseLib/X64/Thunk16.asm
@@ -3,7 +3,7 @@
 

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

 ;

-; Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>

+; Copyright (c) 2006 - 2013, 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

@@ -282,7 +282,7 @@ InternalAsmThunk16  PROC    USES    rbp rbx rsi rdi
     and     eax, 7ffffffeh              ; clear PE, PG bits

     mov     rbp, cr4

     mov     [rcx], ebp                  ; save CR4 in SavedCr4

-    and     ebp, 300h                   ; clear all but PCE and OSFXSR bits

+    and     ebp, NOT 30h                ; clear PAE, PSE bits

     mov     esi, r8d                    ; esi <- 16-bit stack segment

     DB      6ah, DATA32                 ; push DATA32

     pop     rdx                         ; rdx <- 32-bit data segment selector