EdkCompatibilityPkg/Compatibility/BootScriptThunkHelper/BootScriptThunkHelper.c

   1 /** @file
   2   Boot Script Helper SMM driver.
   3
   4   This driver is responsible to store BootScriptThunk from ReservedMemory to SMRAM for security consideration.
   5
   6 Copyright (c) 2010 - 2012, Intel Corporation. All rights reserved.<BR>
   7
   8 This program and the accompanying materials
   9 are licensed and made available under the terms and conditions
  10 of the BSD License which accompanies this distribution.  The
  11 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 <Library/BaseLib.h>
  21 #include <Library/PcdLib.h>
  22 #include <Library/DebugLib.h>
  23 #include <Library/LockBoxLib.h>
  24
  25 #include <Guid/BootScriptThunkData.h>
  26
  27 EFI_GUID mBootScriptThunkGuid = {
  28   0xa053f561, 0xf56b, 0x4140, {0x89, 0x1, 0xb4, 0xcb, 0x5d, 0x70, 0x92, 0x9e}
  29 };
  30
  31 /**
  32   Entry point function of the Boot Script Thunk Helper SMM driver.
  33
  34   @param[in] ImageHandle  The firmware allocated handle for the EFI image.
  35   @param[in] SystemTable  A pointer to the EFI System Table.
  36
  37   @retval EFI_SUCCESS     The entry point is executed successfully.
  38   @retval other           Some error occurs when executing this entry point.
  39 **/
  40 EFI_STATUS
  41 EFIAPI
  42 BootScriptThunkHelperMain (
  43   IN EFI_HANDLE        ImageHandle,
  44   IN EFI_SYSTEM_TABLE  *SystemTable
  45   )
  46 {
  47   BOOT_SCRIPT_THUNK_DATA        *BootScriptThunkData;
  48   EFI_STATUS                    Status;
  49
  50   //
  51   // Get BootScriptThunk variable
  52   //
  53   BootScriptThunkData = (BOOT_SCRIPT_THUNK_DATA *)(UINTN)PcdGet64(BootScriptThunkDataPtr);
  54   ASSERT (BootScriptThunkData != NULL);
  55   if (BootScriptThunkData == NULL) {
  56     return EFI_NOT_FOUND;
  57   }
  58
  59   //
  60   // Save BootScriptThunk image
  61   //
  62   Status = SaveLockBox (
  63              &mBootScriptThunkGuid,
  64              (VOID *)(UINTN)BootScriptThunkData->BootScriptThunkBase,
  65              (UINTN)BootScriptThunkData->BootScriptThunkLength
  66              );
  67   ASSERT_EFI_ERROR (Status);
  68
  69   Status = SetLockBoxAttributes (&mBootScriptThunkGuid, LOCK_BOX_ATTRIBUTE_RESTORE_IN_PLACE);
  70   ASSERT_EFI_ERROR (Status);
  71
  72   return Status;
  73 }