MdePkg/Library/BaseLib/Ia32/WriteDr0.c

   1 /** @file
   2   AsmWriteDr0 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   Writes a value to Debug Register 0 (DR0).
  17
  18   Writes and returns a new value to DR0. This function is only available on
  19   IA-32 and x64. This writes a 32-bit value on IA-32 and a 64-bit value on x64.
  20
  21   @param  Value The value to write to Dr0.
  22
  23   @return The value written to Debug Register 0 (DR0).
  24
  25 **/
  26 UINTN
  27 EFIAPI
  28 AsmWriteDr0 (
  29   IN UINTN Value
  30   )
  31 {
  32   _asm {
  33     mov     eax, Value
  34     mov     dr0, eax
  35   }
  36 }
  37