MdePkg/BaseLib: Support IA32 processors without CLFLUSH

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / ReadGdtr.c

/** @file\r
  AsmReadGdtr function\r
\r
  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>\r
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php.\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
\r
#include "BaseLibInternals.h"\r
\r
\r
/**\r
  Reads the current Global Descriptor Table Register(GDTR) descriptor.\r
\r
  Reads and returns the current GDTR descriptor and returns it in Gdtr. This\r
  function is only available on IA-32 and x64.\r
\r
  @param  Gdtr  The pointer to a GDTR descriptor.\r
\r
**/\r
VOID\r
EFIAPI\r
InternalX86ReadGdtr (\r
  OUT IA32_DESCRIPTOR  *Gdtr\r
  )\r
{\r
  _asm {\r
    mov     eax, Gdtr\r
    sgdt    fword ptr [eax]\r
  }\r
}\r
\r