EdkCompatibilityPkg: Add BootScriptThunkHelper driver

Signed-off-by: jljusten
Reviewed-by: rsun3

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12247 6f19259b-4bc3-4df7-8a09-765794883524

EdkCompatibilityPkg/Compatibility/BootScriptThunkHelper/BootScriptThunkHelper.c

@@ -0,0 +1,73 @@
+/** @file
+  Boot Script Helper SMM driver.
+
+  This driver is responsible to restoer BootScriptThunk from SMRAM to AcpiNvs for security considertion.
+
+Copyright (c) 2010, 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 <PiDxe.h>
+#include <Library/BaseLib.h>
+#include <Library/PcdLib.h>
+#include <Library/DebugLib.h>
+#include <Library/LockBoxLib.h>
+
+#include <Guid/BootScriptThunkData.h>
+
+EFI_GUID mBootScriptThunkGuid = {
+  0xa053f561, 0xf56b, 0x4140, {0x89, 0x1, 0xb4, 0xcb, 0x5d, 0x70, 0x92, 0x9e}
+};
+
+/**
+  Entry point function of the Boot Script Thunk Helper SMM driver.
+
+  @param[in] ImageHandle  The firmware allocated handle for the EFI image.  
+  @param[in] SystemTable  A pointer to the EFI System Table.
+  
+  @retval EFI_SUCCESS     The entry point is executed successfully.
+  @retval other           Some error occurs when executing this entry point.
+**/
+EFI_STATUS
+EFIAPI
+BootScriptThunkHelperMain (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  BOOT_SCRIPT_THUNK_DATA        *BootScriptThunkData;
+  EFI_STATUS                    Status;
+
+  //
+  // Get BootScriptThunk variable
+  //
+  BootScriptThunkData = (BOOT_SCRIPT_THUNK_DATA *)(UINTN)PcdGet64(BootScriptThunkDataPtr);
+  ASSERT (BootScriptThunkData != NULL);
+  if (BootScriptThunkData == NULL) {
+    return EFI_NOT_FOUND;
+  }
+
+  //
+  // Save BootScriptThunk image
+  //
+  Status = SaveLockBox (
+             &mBootScriptThunkGuid,
+             (VOID *)(UINTN)BootScriptThunkData->BootScriptThunkBase,
+             (UINTN)BootScriptThunkData->BootScriptThunkLength
+             );
+  ASSERT_EFI_ERROR (Status);
+
+  Status = SetLockBoxAttributes (&mBootScriptThunkGuid, LOCK_BOX_ATTRIBUTE_RESTORE_IN_PLACE);
+  ASSERT_EFI_ERROR (Status);
+
+  return Status;
+}