From: li-elvin <li-elvin@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Tue, 18 Oct 2011 02:42:34 +0000 (+0000)
Subject: Use a local variable and assign 0 to it, then use it as legacy interrupt table base... 
X-Git-Tag: edk2-stable201903~14057
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=515327a3e3f39f201da09a4916e8c820a104c3c4

Use a local variable and assign 0 to it, then use it as legacy interrupt table base address.

Signed-off-by: li-elvin
Reviewed-by: mdkinney, ydong10

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12544 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/EdkCompatibilityPkg/Foundation/Library/Thunk16/X86Thunk.c b/EdkCompatibilityPkg/Foundation/Library/Thunk16/X86Thunk.c
index ed24663b48..7f562cf484 100644
--- a/EdkCompatibilityPkg/Foundation/Library/Thunk16/X86Thunk.c
+++ b/EdkCompatibilityPkg/Foundation/Library/Thunk16/X86Thunk.c
@@ -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        
@@ -381,8 +381,15 @@ Returns:
 
 --*/
 {
-  RegisterSet->E.EIP = (UINT16)((UINT32 *)NULL)[IntNumber];
-  RegisterSet->E.CS  = (UINT16)(((UINT32 *)NULL)[IntNumber] >> 16);
+  UINT32  *VectorBase;
+  
+  //
+  // The base address of legacy interrupt vector table is 0.
+  // We use this base address to get the legacy interrupt handler.
+  //
+  VectorBase = 0;
+  RegisterSet->E.EIP = (UINT16)(VectorBase)[IntNumber];
+  RegisterSet->E.CS  = (UINT16)((VectorBase)[IntNumber] >> 16);
 
   return AsmThunk16 (ThunkContext, RegisterSet, Flags | THUNK_INTERRUPT);
 }