StandaloneMmPkg: StandaloneMmCoreEntryPoint: Extends support for X64

This change extends StandaloneMmCoreEntryPoint library to support X64
architecture.

Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Supreeth Venkatesh <supreeth.venkatesh@arm.com>

Signed-off-by: Kun Qin <kun.q@outlook.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>

StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/StandaloneMmCoreEntryPoint.inf

@@ -26,6 +26,9 @@
   AArch64/SetPermissions.c
   AArch64/CreateHobList.c
 
+[Sources.X64]
+  X64/StandaloneMmCoreEntryPoint.c
+
 [Packages]
   MdePkg/MdePkg.dec
   MdeModulePkg/MdeModulePkg.dec

StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/X64/StandaloneMmCoreEntryPoint.c

@@ -0,0 +1,71 @@
+/** @file
+  Entry point to the Standalone Mm Core.
+
+Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) Microsoft Corporation.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include <PiMm.h>
+
+#include <Library/StandaloneMmCoreEntryPoint.h>
+#include <Library/DebugLib.h>
+#include <Library/BaseLib.h>
+
+//
+// Cache copy of HobList pointer.
+//
+VOID *gHobList = NULL;
+
+/**
+  The entry point of PE/COFF Image for the STANDALONE MM Core.
+
+  This function is the entry point for the STANDALONE MM Core. This function is required to call
+  ProcessModuleEntryPointList() and ProcessModuleEntryPointList() is never expected to return.
+  The STANDALONE MM Core is responsible for calling ProcessLibraryConstructorList() as soon as the EFI
+  System Table and the image handle for the STANDALONE MM Core itself have been established.
+  If ProcessModuleEntryPointList() returns, then ASSERT() and halt the system.
+
+  @param  HobStart  Pointer to the beginning of the HOB List passed in from the PEI Phase.
+
+**/
+VOID
+EFIAPI
+_ModuleEntryPoint (
+  IN VOID  *HobStart
+  )
+{
+  //
+  // Cache a pointer to the HobList
+  //
+  gHobList = HobStart;
+
+  //
+  // Call the Standalone MM Core entry point
+  //
+  ProcessModuleEntryPointList (HobStart);
+
+  //
+  // TODO: Set page table here?? AARCH64 has this step for some reason
+  //
+}
+
+
+/**
+  Required by the EBC compiler and identical in functionality to _ModuleEntryPoint().
+
+  This function is required to call _ModuleEntryPoint() passing in HobStart.
+
+  @param  HobStart  Pointer to the beginning of the HOB List passed in from the PEI Phase.
+
+**/
+VOID
+EFIAPI
+EfiMain (
+  IN VOID  *HobStart
+  )
+{
+  _ModuleEntryPoint (HobStart);
+}