1 files changed, 66 insertions, 0 deletions
diff --git a/Core/MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.c b/Core/MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.c
new file mode 100644
index 0000000000..750a268001
--- /dev/null
+++ b/Core/MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.c
@@ -0,0 +1,66 @@
+/** @file
+  This library retrieve the EFI_BOOT_SERVICES pointer from EFI system table in 
+  library's constructor.
+
+  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
+  This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+
+#include <Uefi.h>
+
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/DebugLib.h>
+
+EFI_HANDLE         gImageHandle = NULL;
+EFI_SYSTEM_TABLE   *gST         = NULL;
+EFI_BOOT_SERVICES  *gBS         = NULL;
+
+/**
+  The constructor function caches the pointer of Boot Services Table.
+    
+  The constructor function caches the pointer of Boot Services Table through System Table.
+  It will ASSERT() if the pointer of System Table is NULL.
+  It will ASSERT() if the pointer of Boot Services Table is NULL.
+  It will always return EFI_SUCCESS.
+
+  @param  ImageHandle   The firmware allocated handle for the EFI image.
+  @param  SystemTable   A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
+
+**/
+EFI_STATUS
+EFIAPI
+UefiBootServicesTableLibConstructor (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  //
+  // Cache the Image Handle
+  //
+  gImageHandle = ImageHandle;
+  ASSERT (gImageHandle != NULL);
+
+  //
+  // Cache pointer to the EFI System Table
+  //
+  gST = SystemTable;
+  ASSERT (gST != NULL);
+
+  //
+  // Cache pointer to the EFI Boot Services Table
+  //
+  gBS = SystemTable->BootServices;
+  ASSERT (gBS != NULL);
+
+  return EFI_SUCCESS;
+}