MdePkg/Library/DxeServicesTableLib/DxeServicesTableLib.c

   1 /** @file
   2   This library produce EFI_DXE_SERVICE pointer in global EFI system table. It should
   3   be linked to a DXE driver who use gBS.
   4
   5   This library contains contruct function to retrieve EFI_DXE_SERIVCE, this construct
   6   function will be invoked in DXE driver's autogen file.
   7
   8   Copyright (c) 2006, Intel Corporation<BR>
   9   All rights reserved. This program and the accompanying materials
  10   are licensed and made available under the terms and conditions of the BSD License
  11   which accompanies this distribution.  The full text of the license may be found at
  12   http://opensource.org/licenses/bsd-license.php
  13
  14   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  15   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  16
  17 **/
  18
  19 #include <PiDxe.h>
  20 #include <Guid/DxeServices.h>
  21 #include <Library/DxeServicesTableLib.h>
  22 #include <Library/DebugLib.h>
  23 #include <Library/UefiLib.h>
  24
  25 //
  26 // Cache copy of the DXE Services Table
  27 //
  28 EFI_DXE_SERVICES  *gDS      = NULL;
  29
  30 /**
  31   The constructor function caches the pointer of DXE Services Table.
  32
  33   The constructor function caches the pointer of DXE Services Table.
  34   It will ASSERT() if that operation fails.
  35   It will ASSERT() if the pointer of DXE Services Table is NULL.
  36   It will always return EFI_SUCCESS.
  37
  38   @param  ImageHandle   The firmware allocated handle for the EFI image.
  39   @param  SystemTable   A pointer to the EFI System Table.
  40
  41   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
  42
  43 **/
  44 EFI_STATUS
  45 EFIAPI
  46 DxeServicesTableLibConstructor (
  47   IN EFI_HANDLE        ImageHandle,
  48   IN EFI_SYSTEM_TABLE  *SystemTable
  49   )
  50 {
  51   EFI_STATUS  Status;
  52
  53   //
  54   // Cache copy of the DXE Services Table
  55   //
  56   Status = EfiGetSystemConfigurationTable (&gEfiDxeServicesTableGuid, (VOID **) &gDS);
  57   ASSERT_EFI_ERROR (Status);
  58   ASSERT (gDS != NULL);
  59
  60   return Status;
  61 }