1 /** @file
2   AsmDisableCache function
3 
4   Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
5   This program and the accompanying materials
6   are licensed and made available under the terms and conditions of the BSD License
7   which accompanies this distribution.  The full text of the license may be found at
8   http://opensource.org/licenses/bsd-license.php.
9 
10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12 
13 **/
14 
15 /**
16   Set CD bit and clear NW bit of CR0 followed by a WBINVD.
17 
18   Disables the caches by setting the CD bit of CR0 to 1, clearing the NW bit of CR0 to 0,
19   and executing a WBINVD instruction.  This function is only available on IA-32 and x64.
20 
21 **/
22 VOID
23 EFIAPI
AsmDisableCache(VOID)24 AsmDisableCache (
25   VOID
26   )
27 {
28   _asm {
29     mov     eax, cr0
30     bts     eax, 30
31     btr     eax, 29
32     mov     cr0, eax
33     wbinvd
34   }
35 }
36 
37