audk/MdePkg/Library/MmServicesTableLib/MmServicesTableLib.c

58 lines
1.7 KiB
C

/** @file
MM Services Table Library.
Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2018, Linaro, Ltd. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <PiMm.h>
#include <Protocol/MmBase.h>
#include <Library/MmServicesTableLib.h>
#include <Library/DebugLib.h>
EFI_MM_SYSTEM_TABLE *gMmst = NULL;
/**
The constructor function caches the pointer of the MM 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
MmServicesTableLibConstructor (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
EFI_MM_BASE_PROTOCOL *InternalMmBase;
InternalMmBase = NULL;
//
// Retrieve MM Base Protocol, Do not use gBS from UefiBootServicesTableLib on purpose
// to prevent inclusion of gBS, gST, and gImageHandle from SMM Drivers unless the
// MM driver explicity declares that dependency.
//
Status = SystemTable->BootServices->LocateProtocol (
&gEfiMmBaseProtocolGuid,
NULL,
(VOID **)&InternalMmBase
);
ASSERT_EFI_ERROR (Status);
ASSERT (InternalMmBase != NULL);
//
// We are in MM, retrieve the pointer to MM System Table
//
InternalMmBase->GetMmstLocation (InternalMmBase, &gMmst);
ASSERT (gMmst != NULL);
return EFI_SUCCESS;
}