Fix the bug that EntryPoint of DisablePaging64() is corrupted.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7250 6f19259b-4bc3-4df7-8a09-765794883524

2 files changed, 7 insertions, 3 deletions

diff --git a/MdePkg/Library/BaseLib/X64/DisablePaging64.S b/MdePkg/Library/BaseLib/X64/DisablePaging64.S
index a55059e3be..8c71d2d49e 100644
--- a/MdePkg/Library/BaseLib/X64/DisablePaging64.S
+++ b/MdePkg/Library/BaseLib/X64/DisablePaging64.S
@@ -51,6 +51,8 @@ L1:
     mov    %cr0,%rax

     btr    $0x1f,%eax

     mov    %rax,%cr0                      # disable paging

+

+    mov    %rdx,%rbx                      # save EntryPoint to rbx, for rdmsr will overwrite rdx

     mov    $0xc0000080,%ecx

     rdmsr  

     and    $0xfe,%ah                      # clear LME

@@ -60,6 +62,6 @@ L1:
     mov    %rax,%cr4

     push   %rdi                           # push Context2

     push   %rsi                           # push Context1

-    callq  *%rdx                          # transfer control to EntryPoint

+    callq  *%rbx                          # transfer control to EntryPoint

     jmp    .                              # no one should get here

 

diff --git a/MdePkg/Library/BaseLib/X64/DisablePaging64.asm b/MdePkg/Library/BaseLib/X64/DisablePaging64.asm
index 518137ddc9..29bf558e6c 100644
--- a/MdePkg/Library/BaseLib/X64/DisablePaging64.asm
+++ b/MdePkg/Library/BaseLib/X64/DisablePaging64.asm
@@ -1,6 +1,6 @@
 ;------------------------------------------------------------------------------

 ;

-; Copyright (c) 2006, Intel Corporation

+; Copyright (c) 2006 - 2008, Intel Corporation

 ; All rights reserved. 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

@@ -49,6 +49,8 @@ InternalX86DisablePaging64    PROC
     mov     rax, cr0

     btr     eax, 31

     mov     cr0, rax                    ; disable paging

+

+    mov     rbx, rdx                    ; save EntryPoint to rbx, for rdmsr will overwrite rdx

     mov     ecx, 0c0000080h

     rdmsr

     and     ah, NOT 1                   ; clear LME

@@ -58,7 +60,7 @@ InternalX86DisablePaging64    PROC
     mov     cr4, rax

     push    rdi                         ; push Context2

     push    rsi                         ; push Context1

-    call    rdx                         ; transfer control to EntryPoint

+    call    rbx                         ; transfer control to EntryPoint

     hlt                                 ; no one should get here

 InternalX86DisablePaging64    ENDP