audk/MdePkg/Library/SmmServicesTableLib/SmmServicesTableLib.c

80 lines
2.1 KiB
C

/** @file
SMM Services Table Library.
Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#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 explicitly 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;
}