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-rw-r--r--MdePkg/Library/MmServicesTableLib/MmServicesTableLib.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/MdePkg/Library/MmServicesTableLib/MmServicesTableLib.c b/MdePkg/Library/MmServicesTableLib/MmServicesTableLib.c
new file mode 100644
index 000000000000..a603754f1ecd
--- /dev/null
+++ b/MdePkg/Library/MmServicesTableLib/MmServicesTableLib.c
@@ -0,0 +1,57 @@
+/** @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;
+}