MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.c

   1 /** @file
   2   UEFI Boot Services Table Library.
   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   Module Name:  UefiBootServicesTableLib.c
  14
  15 **/
  16
  17 //
  18 // Include common header file for this module.
  19 //
  20 #include "CommonHeader.h"
  21
  22 EFI_HANDLE         gImageHandle = NULL;
  23 EFI_SYSTEM_TABLE   *gST         = NULL;
  24 EFI_BOOT_SERVICES  *gBS         = NULL;
  25
  26 /**
  27   The constructor function caches the pointer of Boot Services Table.
  28
  29   The constructor function caches the pointer of Boot Services Table through System Table.
  30   It will ASSERT() if the pointer of System Table is NULL.
  31   It will ASSERT() if the pointer of Boot Services Table is NULL.
  32   It will always return EFI_SUCCESS.
  33
  34   @param  ImageHandle   The firmware allocated handle for the EFI image.
  35   @param  SystemTable   A pointer to the EFI System Table.
  36
  37   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
  38
  39 **/
  40 EFI_STATUS
  41 EFIAPI
  42 UefiBootServicesTableLibConstructor (
  43   IN EFI_HANDLE        ImageHandle,
  44   IN EFI_SYSTEM_TABLE  *SystemTable
  45   )
  46 {
  47   //
  48   // Cache the Image Handle
  49   //
  50   gImageHandle = ImageHandle;
  51   ASSERT (gImageHandle != NULL);
  52
  53   //
  54   // Cache pointer to the EFI System Table
  55   //
  56   gST = SystemTable;
  57   ASSERT (gST != NULL);
  58
  59   //
  60   // Cache pointer to the EFI Boot Services Table
  61   //
  62   gBS = SystemTable->BootServices;
  63   ASSERT (gBS != NULL);
  64
  65   return EFI_SUCCESS;
  66 }