StandaloneMmPkg: Create null instance for MmPlatformHobProducerLib

Create null instance MmPlatformHobProducerLibNull.inf for
MmPlatformHobProducerLib.

Signed-off-by: Dun Tan <dun.tan@intel.com>

StandaloneMmPkg/Library/MmPlatformHobProducerLibNull/MmPlatformHobProducerLibNull.c

@@ -0,0 +1,66 @@
+/** @file
+  Null instance of MM Platform HOB Producer Library Class.
+
+  CreateMmPlatformHob() function is called by StandaloneMm IPL to create all
+  Platform specific HOBs that required by Standalone MM environment.
+
+  Copyright (c) 2024, Intel Corporation. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+#include <PiPei.h>
+#include <Library/MmPlatformHobProducerLib.h>
+
+/**
+  Create the platform specific HOBs needed by the Standalone MM environment.
+
+  The following HOBs are created by StandaloneMm IPL common logic.
+  Hence they should NOT be created by this function:
+  * Single EFI_HOB_TYPE_FV to describe the Firmware Volume where MM Core resides.
+  * Single GUIDed (gEfiSmmSmramMemoryGuid) HOB to describe the MM regions.
+  * Single EFI_HOB_MEMORY_ALLOCATION_MODULE to describe the MM region used by MM Core.
+  * Multiple EFI_HOB_RESOURCE_DESCRIPTOR to describe the non-MM regions and their access permissions.
+    Note: All accessible non-MM regions should be described by EFI_HOB_RESOURCE_DESCRIPTOR HOBs.
+  * Single GUIDed (gMmCommBufferHobGuid) HOB to identify MM Communication buffer in non-MM region.
+  * Multiple GUIDed (gSmmBaseHobGuid) HOB to describe the SMM base address of each processor.
+  * Multiple GUIDed (gMpInformation2HobGuid) HOB to describe the MP information.
+  * Single GUIDed (gMmCpuSyncConfigHobGuid) HOB to describe how BSP synchronizes with APs in x86 SMM.
+  * Single GUIDed (gMmAcpiS3EnableHobGuid) HOB to describe the ACPI S3 enable status.
+  * Single GUIDed (gEfiAcpiVariableGuid) HOB to identify the S3 data root region in x86.
+  * Single GUIDed (gMmProfileDataHobGuid) HOB to describe the MM profile data region.
+
+  @param[in]      Buffer            The free buffer to be used for HOB creation.
+  @param[in, out] BufferSize        The buffer size.
+                                    On return, the expected/used size.
+
+  @retval RETURN_INVALID_PARAMETER  BufferSize is NULL.
+  @retval RETURN_INVALID_PARAMETER  Buffer is NULL and BufferSize is not 0.
+  @retval RETURN_BUFFER_TOO_SMALL   The buffer is too small for HOB creation.
+                                    BufferSize is updated to indicate the expected buffer size.
+                                    When the input BufferSize is bigger than the expected buffer size,
+                                    the BufferSize value will be changed to the used buffer size.
+  @retval RETURN_SUCCESS            The HOB list is created successfully.
+
+**/
+EFI_STATUS
+EFIAPI
+CreateMmPlatformHob (
+  IN      VOID   *Buffer,
+  IN OUT  UINTN  *BufferSize
+  )
+{
+  if (BufferSize == NULL) {
+    return RETURN_INVALID_PARAMETER;
+  }
+
+  if ((*BufferSize != 0) && (Buffer == NULL)) {
+    return RETURN_INVALID_PARAMETER;
+  }
+
+  *BufferSize = 0;
+
+  return EFI_SUCCESS;
+}

StandaloneMmPkg/Library/MmPlatformHobProducerLibNull/MmPlatformHobProducerLibNull.inf

@@ -0,0 +1,28 @@
+## @file
+# Null instance of MM Platform HOB Producer Library Class.
+#
+# Copyright (c) 2024, Intel Corporation. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010017
+  BASE_NAME                      = MmPlatformHobProducerLibNull
+  FILE_GUID                      = DE6B5E7C-6636-4646-90F8-776408157750
+  MODULE_TYPE                    = PEIM
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = MmPlatformHobProducerLib
+
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  MmPlatformHobProducerLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  StandaloneMmPkg/StandaloneMmPkg.dec

StandaloneMmPkg/StandaloneMmPkg.dsc

@@ -60,6 +60,7 @@
   StandaloneMmDriverEntryPoint|MdePkg/Library/StandaloneMmDriverEntryPoint/StandaloneMmDriverEntryPoint.inf
   VariableMmDependency|StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.inf
   HobPrintLib|MdeModulePkg/Library/HobPrintLib/HobPrintLib.inf
+  MmPlatformHobProducerLib|StandaloneMmPkg/Library/MmPlatformHobProducerLibNull/MmPlatformHobProducerLibNull.inf
 
 [LibraryClasses.AARCH64, LibraryClasses.ARM]
   ArmLib|ArmPkg/Library/ArmLib/ArmBaseLib.inf
@@ -119,6 +120,7 @@
   StandaloneMmPkg/Library/StandaloneMmMemoryAllocationLib/StandaloneMmMemoryAllocationLib.inf
   StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.inf
   StandaloneMmPkg/Library/SmmLockBoxMmDependency/SmmLockBoxMmDependency.inf
+  StandaloneMmPkg/Library/MmPlatformHobProducerLibNull/MmPlatformHobProducerLibNull.inf
 
 [Components.AARCH64, Components.ARM]
   StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.inf