MdePkg/Library/BaseLib/Ia32/ReadIdtr.c

   1 /** @file
   2   AsmReadIdtr function
   3
   4   Copyright (c) 2006 - 2007, Intel Corporation<BR>
   5   All rights reserved. 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 // Include common header file for this module.
  17 //
  18 #include <BaseLibInternals.h>
  19
  20
  21 /**
  22   Reads the current Interrupt Descriptor Table Register(GDTR) descriptor.
  23
  24   Reads and returns the current IDTR descriptor and returns it in Idtr. This
  25   function is only available on IA-32 and X64.
  26
  27   @param  Idtr  Pointer to a IDTR descriptor.
  28
  29 **/
  30 VOID
  31 EFIAPI
  32 InternalX86ReadIdtr (
  33   OUT     IA32_DESCRIPTOR           *Idtr
  34   )
  35 {
  36   _asm {
  37     mov     eax, Idtr
  38     sidt    fword ptr [eax]
  39   }
  40 }