audk/MdePkg/Library/SmmServicesTableLib/SmmServicesTableLib.c

105 lines
2.6 KiB
C

/** @file
SMM Services Table Library.
Copyright (c) 2009, Intel Corporation<BR>
All rights reserved. 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 <PiSmm.h>
#include <Protocol/SmmBase2.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/SmmServicesTableLib.h>
#include <Library/DebugLib.h>
EFI_SMM_SYSTEM_TABLE2 *gSmst = NULL;
EFI_SMM_BASE2_PROTOCOL *mInternalSmmBase2 = 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;
BOOLEAN InSmm;
//
// Retrieve SMM Base2 Protocol
//
Status = gBS->LocateProtocol (
&gEfiSmmBase2ProtocolGuid,
NULL,
(VOID **) &mInternalSmmBase2
);
ASSERT_EFI_ERROR (Status);
ASSERT (mInternalSmmBase2 != NULL);
//
// Check to see if we are already in SMM
//
mInternalSmmBase2->InSmm (mInternalSmmBase2, &InSmm);
if (!InSmm) {
//
// We are not in SMM, so SMST is not needed
//
return EFI_SUCCESS;
}
//
// We are in SMM, retrieve the pointer to SMM System Table
//
mInternalSmmBase2->GetSmstLocation (mInternalSmmBase2, &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
)
{
BOOLEAN InSmm;
//
// Check to see if we are already in SMM
//
mInternalSmmBase2->InSmm (mInternalSmmBase2, &InSmm);
return InSmm;
}