MdePkg/Library/BaseLib/Ia32/EnableCache.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
   4 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6 ; Module Name:
   7 ;
   8 ;   EnableCache.Asm
   9 ;
  10 ; Abstract:
  11 ;
  12 ;  Flush all caches with a WBINVD instruction, clear the CD bit of CR0 to 0, and clear
  13 ;  the NW bit of CR0 to 0
  14 ;
  15 ; Notes:
  16 ;
  17 ;------------------------------------------------------------------------------
  18
  19     SECTION .text
  20
  21 ;------------------------------------------------------------------------------
  22 ; VOID
  23 ; EFIAPI
  24 ; AsmEnableCache (
  25 ;   VOID
  26 ;   );
  27 ;------------------------------------------------------------------------------
  28 global ASM_PFX(AsmEnableCache)
  29 ASM_PFX(AsmEnableCache):
  30     wbinvd
  31     mov     eax, cr0
  32     btr     eax, 29
  33     btr     eax, 30
  34     mov     cr0, eax
  35     ret
  36