1 files changed, 85 insertions, 0 deletions
diff --git a/Core/MdePkg/Library/SmmServicesTableLib/SmmServicesTableLib.c b/Core/MdePkg/Library/SmmServicesTableLib/SmmServicesTableLib.c
new file mode 100644
index 0000000000..81e5ce8e3f
--- /dev/null
+++ b/Core/MdePkg/Library/SmmServicesTableLib/SmmServicesTableLib.c
@@ -0,0 +1,85 @@
+/** @file
+  SMM Services Table Library.
+
+  Copyright (c) 2009 - 2015, 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 <PiSmm.h>
+#include <Protocol/SmmBase2.h>
+#include <Library/SmmServicesTableLib.h>
+#include <Library/DebugLib.h>
+
+EFI_SMM_SYSTEM_TABLE2   *gSmst             = NULL;
+
+/**
+  The constructor function caches the pointer of SMM Services Table.
+
+  @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
+SmmServicesTableLibConstructor (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS              Status;
+  EFI_SMM_BASE2_PROTOCOL  *InternalSmmBase2;
+
+  InternalSmmBase2 = NULL;
+  //
+  // Retrieve SMM Base2 Protocol,  Do not use gBS from UefiBootServicesTableLib on purpose
+  // to prevent inclusion of gBS, gST, and gImageHandle from SMM Drivers unless the 
+  // SMM driver explicity declares that dependency. 
+  //
+  Status = SystemTable->BootServices->LocateProtocol (
+                                        &gEfiSmmBase2ProtocolGuid,
+                                        NULL,
+                                        (VOID **)&InternalSmmBase2
+                                        );
+  ASSERT_EFI_ERROR (Status);
+  ASSERT (InternalSmmBase2 != NULL);
+
+  //
+  // We are in SMM, retrieve the pointer to SMM System Table
+  //
+  InternalSmmBase2->GetSmstLocation (InternalSmmBase2, &gSmst);
+  ASSERT (gSmst != NULL);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  This function allows the caller to determine if the driver is executing in 
+  System Management Mode(SMM).
+
+  This function returns TRUE if the driver is executing in SMM and FALSE if the 
+  driver is not executing in SMM.
+
+  @retval  TRUE  The driver is executing in System Management Mode (SMM).
+  @retval  FALSE The driver is not executing in System Management Mode (SMM). 
+
+**/
+BOOLEAN
+EFIAPI
+InSmm (
+  VOID
+  )
+{
+  //
+  // We are already in SMM
+  //
+  return TRUE;
+}