MdePkg/Library/BaseLib/Ia32/ReadDr5.c

   1 /** @file
   2   AsmReadDr5 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
  17
  18 /**
  19   Reads the current value of Debug Register 5 (DR5).
  20
  21   Reads and returns the current value of DR5. This function is only available
  22   on IA-32 and x64. This returns a 32-bit value on IA-32 and a 64-bit value on
  23   x64.
  24
  25   @return The value of Debug Register 5 (DR5).
  26
  27 **/
  28 UINTN
  29 EFIAPI
  30 AsmReadDr5 (
  31   VOID
  32   )
  33 {
  34   __asm {
  35     _emit  0x0f
  36     _emit  0x21
  37     _emit  0xe8
  38   }
  39 }
  40