MdePkg/Library/BaseLib/Ia32/DisableCache.c

   1 /** @file
   2   AsmDisableCache function
   3
   4   Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 /**
  10   Set CD bit and clear NW bit of CR0 followed by a WBINVD.
  11
  12   Disables the caches by setting the CD bit of CR0 to 1, clearing the NW bit of CR0 to 0,
  13   and executing a WBINVD instruction.  This function is only available on IA-32 and x64.
  14
  15 **/
  16 VOID
  17 EFIAPI
  18 AsmDisableCache (
  19   VOID
  20   )
  21 {
  22   _asm {
  23     mov     eax, cr0
  24     bts     eax, 30
  25     btr     eax, 29
  26     mov     cr0, eax
  27     wbinvd
  28   }
  29 }
  30