MdePkg/Library/BaseLib/X64/ReadDr4.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
   4 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6 ; Module Name:
   7 ;
   8 ;   ReadDr4.Asm
   9 ;
  10 ; Abstract:
  11 ;
  12 ;   AsmReadDr4 function
  13 ;
  14 ; Notes:
  15 ;
  16 ;------------------------------------------------------------------------------
  17
  18     DEFAULT REL
  19     SECTION .text
  20
  21 ;------------------------------------------------------------------------------
  22 ; UINTN
  23 ; EFIAPI
  24 ; AsmReadDr4 (
  25 ;   VOID
  26 ;   );
  27 ;------------------------------------------------------------------------------
  28 global ASM_PFX(AsmReadDr4)
  29 ASM_PFX(AsmReadDr4):
  30     ;
  31     ; There's no obvious reason to access this register, since it's aliased to
  32     ; DR7 when DE=0 or an exception generated when DE=1
  33     ;
  34     DB      0xf, 0x21, 0xe0
  35     ret
  36