diff --git a/BootloaderCommonPkg/Include/Guid/MpCpuTaskInfoHob.h b/BootloaderCommonPkg/Include/Guid/MpCpuTaskInfoHob.h
index 9f9a0ea1..0454fd37 100644
--- a/BootloaderCommonPkg/Include/Guid/MpCpuTaskInfoHob.h
+++ b/BootloaderCommonPkg/Include/Guid/MpCpuTaskInfoHob.h
@@ -20,9 +20,10 @@ typedef enum {
   EnumCpuReady,
   EnumCpuStart,
   EnumCpuEnd,
+  EnumCpuReturn,
 } CPU_STATE;
 
-typedef UINT64 (*CPU_TASK_FUNC)          (UINT64 Arg);
+typedef UINT64 (EFIAPI *CPU_TASK_FUNC)          (UINT64 Arg);
 
 #pragma pack(1)
 
@@ -43,12 +44,12 @@ typedef struct {
 } CPU_TASK;
 
 typedef struct {
-  UINT32           CpuCount;
-  CPU_TASK         CpuTask[0];
+  UINT32          CpuCount;
+  CPU_TASK        CpuTask[0];
 } SYS_CPU_TASK;
 
 typedef struct {
-  SYS_CPU_TASK     *SysCpuTask;
+  EFI_PHYSICAL_ADDRESS  SysCpuTask;
 } SYS_CPU_TASK_HOB;
 
 #pragma pack()
diff --git a/BootloaderCorePkg/Stage2/Stage2Support.c b/BootloaderCorePkg/Stage2/Stage2Support.c
index 7a11af1a..144d4876 100644
--- a/BootloaderCorePkg/Stage2/Stage2Support.c
+++ b/BootloaderCorePkg/Stage2/Stage2Support.c
@@ -589,8 +589,9 @@ BuildExtraInfoHob (
   if (GetPayloadId () == 0) {
     Length        = sizeof (SYS_CPU_TASK_HOB);
     SysCpuTaskHob = BuildGuidHob (&gLoaderMpCpuTaskInfoGuid, Length);
+
     if (SysCpuTaskHob != NULL) {
-      SysCpuTaskHob->SysCpuTask = MpGetTask ();
+      SysCpuTaskHob->SysCpuTask = (UINTN) MpGetTask();
     }
   }
 
diff --git a/PayloadPkg/Include/Library/PayloadEntryLib.h b/PayloadPkg/Include/Library/PayloadEntryLib.h
index f3096479..f3429f48 100644
--- a/PayloadPkg/Include/Library/PayloadEntryLib.h
+++ b/PayloadPkg/Include/Library/PayloadEntryLib.h
@@ -8,6 +8,19 @@
 #ifndef __PAYLOAD_ENTRY_LIB_H__
 #define __PAYLOAD_ENTRY_LIB_H__
 
+typedef  struct {
+  UINT32   Signature;
+  UINT32   HeapBase;
+  UINT32   HeapSize;
+  UINT32   RsvdBase;
+  UINT32   RsvdSize;
+  UINT32   Argc;
+  UINT32   Argv[4];
+} PLD_EXTRA_MOD_ARGS;
+
+typedef  EFI_STATUS (EFIAPI *PLD_MODULE_ENTRY) \
+         (VOID *HobList, PLD_EXTRA_MOD_ARGS *Params);
+
 /**
   The payload common Entry Point for C code.
 
diff --git a/PayloadPkg/OsLoader/ExtraModSupport.c b/PayloadPkg/OsLoader/ExtraModSupport.c
new file mode 100644
index 00000000..c692e3df
--- /dev/null
+++ b/PayloadPkg/OsLoader/ExtraModSupport.c
@@ -0,0 +1,93 @@
+/** @ Provide API to call extra modules
+
+  Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "OsLoader.h"
+
+#define  RTCM_HEAP_SIZE       0x10000
+#define  RTCM_RSVD_SIZE       0xFF000
+#define  MOD_DEF_HEAP_SIZE    0x10000
+#define  MOD_DEF_RSVD_SIZE    0x04000
+
+/**
+  Call into an extra image entrypoint.
+
+  Detect and call into the image entrypoint. If required, handle thunk call
+  as well.
+
+  @param[in]  ModSignature      Module signature.
+  @param[in]  LoadedImage       Loaded Image information, expected to be PE32 format.
+
+  @retval  EFI_SUCCESS          Image returns successfully
+  @retval  Others               There is error during the module call.
+
+**/
+EFI_STATUS
+CallExtraModule (
+  IN   UINT32           ModSignature,
+  IN   LOADED_IMAGE    *LoadedImage
+  )
+{
+  EFI_STATUS           Status;
+  UINT16               PldMachine;
+  PLD_MODULE_ENTRY     PldEntry;
+  VOID                *HobList;
+  PLD_EXTRA_MOD_ARGS   ModArgs;
+  VOID                *ExtraImageBase;
+
+  ExtraImageBase = LoadedImage->ImageData.Addr;
+
+  // Prepare memory for extra modules
+  ZeroMem (&ModArgs, sizeof(ModArgs));
+  ModArgs.Signature  = ModSignature;
+  if (ModSignature == PLD_EXTRA_MOD_RTCM) {
+    ModArgs.RsvdSize   = RTCM_RSVD_SIZE;
+    ModArgs.HeapSize   = RTCM_HEAP_SIZE;
+  } else {
+    ModArgs.RsvdSize   = MOD_DEF_RSVD_SIZE;
+    ModArgs.HeapSize   = MOD_DEF_HEAP_SIZE;
+  }
+  ModArgs.RsvdBase   = (UINT32)(UINTN) AllocateReservedPages (EFI_SIZE_TO_PAGES (ModArgs.RsvdSize));
+  ModArgs.HeapBase   = (UINT32)(UINTN) AllocatePages (EFI_SIZE_TO_PAGES (ModArgs.HeapSize));
+  ASSERT (ModArgs.HeapBase != 0);
+  ASSERT (ModArgs.RsvdBase != 0);
+
+  // Get entrypoint and call into module with thunk support
+  Status = PeCoffLoaderGetMachine (ExtraImageBase, &PldMachine);
+  if (!EFI_ERROR(Status)) {
+    Status = PeCoffLoaderGetEntryPoint (ExtraImageBase, (VOID *)&PldEntry);
+  }
+
+  if (!EFI_ERROR(Status)) {
+    if (IS_X64) {
+      if (PldMachine == IMAGE_FILE_MACHINE_I386) {
+        DEBUG ((DEBUG_INFO, "Switch to x86 Mode\n"));
+      }
+    } else {
+      if (PldMachine == IMAGE_FILE_MACHINE_X64) {
+        DEBUG ((DEBUG_INFO, "Switch to x64 Mode\n"));
+      }
+    }
+    DEBUG ((DEBUG_INIT, "Call Extra Module Entry @ 0x%p \n", PldEntry));
+    HobList = (VOID *)(UINTN) PcdGet32 (PcdPayloadHobList);
+    if (PldMachine == IMAGE_FILE_MACHINE_X64) {
+      Status = Execute64BitCode ((UINT64)(UINTN)PldEntry, (UINT64)(UINTN)HobList,
+                                 (UINT64)(UINTN)&ModArgs, FALSE);
+    } else {
+
+      Status = Execute32BitCode ((UINT64)(UINTN)PldEntry, (UINT64)(UINTN)HobList,
+                                 (UINT64)(UINTN)&ModArgs, FALSE);
+    }
+    DEBUG ((DEBUG_INFO, "Extra Module Returned: %r\n", Status));
+  }
+
+  // Deallocate heap memory, but keep reserved memory
+  if (ModArgs.HeapBase != 0) {
+    FreePages ((VOID *)(UINTN)ModArgs.HeapBase, EFI_SIZE_TO_PAGES (ModArgs.HeapSize));
+  }
+
+  return Status;
+}
diff --git a/PayloadPkg/OsLoader/LoadImage.c b/PayloadPkg/OsLoader/LoadImage.c
index ffbf99aa..c7e8c49b 100644
--- a/PayloadPkg/OsLoader/LoadImage.c
+++ b/PayloadPkg/OsLoader/LoadImage.c
@@ -65,11 +65,10 @@ GetBootImageFromIfwiContainer (
 
   if ((Image->ContainerSig == SIGNATURE_32 ('I', 'P', 'F', 'W')) && (Image->ComponentName == SIGNATURE_32 ('T', 'C', 'C', 'R'))) {
     //
-    // TCC RTCM image need runtime memory
+    // TCC RTCM image need reserved memory
     //
-    LoadedImage->ImageData.Addr = AllocateRuntimePages(EFI_SIZE_TO_PAGES(ImageSize));
-    if (LoadedImage->ImageData.Addr == NULL)
-    {
+    LoadedImage->ImageData.Addr = AllocateReservedPages (EFI_SIZE_TO_PAGES(ImageSize));
+    if (LoadedImage->ImageData.Addr == NULL) {
       return EFI_OUT_OF_RESOURCES;
     }
     CopyMem(LoadedImage->ImageData.Addr, Buffer, ImageSize);
diff --git a/PayloadPkg/OsLoader/OsLoader.c b/PayloadPkg/OsLoader/OsLoader.c
index a47cf5ba..c3dbff11 100644
--- a/PayloadPkg/OsLoader/OsLoader.c
+++ b/PayloadPkg/OsLoader/OsLoader.c
@@ -1038,7 +1038,8 @@ StartBootImages (
       break;
     }
     if ((LoadedExtraImage != NULL) && ((LoadedExtraImage->Flags & LOADED_IMAGE_RUN_EXTRA) != 0)) {
-      Status = StartBooting (LoadedExtraImage);
+      // For now, only RTCM will be supported.
+      Status = CallExtraModule (PLD_EXTRA_MOD_RTCM, LoadedExtraImage);
       if (EFI_ERROR (Status)) {
         return Status;
       }
@@ -1052,7 +1053,7 @@ StartBootImages (
 
   Status = GetLoadedImageByType (LoadedImageHandle, LoadImageTypePreOs, &LoadedPreOsImage);
   if (EFI_ERROR (Status)) {
-      Status = StartBooting (LoadedImage);
+    Status = StartBooting (LoadedImage);
   } else {
     // PreOs found, need start PreOS
     Status = StartPreOsBooting (LoadedPreOsImage, LoadedImage);
diff --git a/PayloadPkg/OsLoader/OsLoader.h b/PayloadPkg/OsLoader/OsLoader.h
index 7f89dd07..6acebd48 100644
--- a/PayloadPkg/OsLoader/OsLoader.h
+++ b/PayloadPkg/OsLoader/OsLoader.h
@@ -45,6 +45,7 @@
 #include <Library/UsbKbLib.h>
 #include <Library/ElfLib.h>
 #include <Library/LinuxLib.h>
+#include <Library/ThunkLib.h>
 #include <Library/ContainerLib.h>
 #include <Library/DebugLogBufferLib.h>
 #include <Guid/SeedInfoHobGuid.h>
@@ -89,6 +90,8 @@
 #define MAX_BOOT_MENU_ENTRY      8
 #define MAX_STR_SLICE_LEN        16
 
+#define PLD_EXTRA_MOD_RTCM       SIGNATURE_32('R', 'T', 'C', 'M')
+
 typedef struct {
   UINT32       Pos;
   UINT32       Len;
@@ -543,4 +546,25 @@ StartPreOsBooting (
   IN LOADED_IMAGE            *LoadedPreOsImage,
   IN LOADED_IMAGE            *LoadedImage
   );
+
+
+/**
+  Call into an extra image entrypoint.
+
+  Detect and call into the image entrypoint. If required, handle thunk call
+  as well.
+
+  @param[in]  ModSignature      Module signature.
+  @param[in]  LoadedImage       Loaded Image information, expected to be PE32 format.
+
+  @retval  EFI_SUCCESS          Image returns successfully
+  @retval  Others               There is error during the module call.
+
+**/
+EFI_STATUS
+CallExtraModule (
+  IN   UINT32           ModSignature,
+  IN   LOADED_IMAGE    *LoadedImage
+  );
+
 #endif
diff --git a/PayloadPkg/OsLoader/OsLoader.inf b/PayloadPkg/OsLoader/OsLoader.inf
index 1c0f6384..c9e04195 100644
--- a/PayloadPkg/OsLoader/OsLoader.inf
+++ b/PayloadPkg/OsLoader/OsLoader.inf
@@ -39,6 +39,7 @@
   PreOsSupport.c
   PreOsChecker.c
   ModService.c
+  ExtraModSupport.c
 
 [Packages]
   MdePkg/MdePkg.dec
diff --git a/PayloadPkg/PayloadPkg.dsc b/PayloadPkg/PayloadPkg.dsc
index 653516d0..9830edf2 100644
--- a/PayloadPkg/PayloadPkg.dsc
+++ b/PayloadPkg/PayloadPkg.dsc
@@ -39,6 +39,7 @@
   BaseMemoryLib | MdePkg/Library/BaseMemoryLibSse2/BaseMemoryLibSse2.inf
   IoLib | MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsic.inf
   PrintLib | MdePkg/Library/BasePrintLib/BasePrintLib.inf
+  SynchronizationLib|MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
   HobLib | BootloaderCommonPkg/Library/HobLib/HobLib.inf
   DebugLogBufferLib | BootloaderCommonPkg/Library/DebugLogBufferLib/DebugLogBufferLib.inf
   SerialPortLib | BootloaderCommonPkg/Library/SerialPortLib/SerialPortLib.inf
@@ -59,6 +60,10 @@
   PayloadEntryLib | PayloadPkg/Library/PayloadEntryLib/PayloadEntryLib.inf
   PlatformHookLib | PayloadPkg/Library/PlatformHookLib/PlatformHookLib.inf
   PagingLib|BootloaderCommonPkg/Library/PagingLib/PagingLib.inf
+  ThunkLib|BootloaderCommonPkg/Library/ThunkLib/ThunkLib.inf
+  LitePeCoffLib|BootloaderCommonPkg/Library/LitePeCoffLib/LitePeCoffLib.inf
+  DebugAgentLib|BootloaderCommonPkg/Library/DebugAgentLib/DebugAgentLibNull.inf
+  TimerLib|BootloaderCommonPkg/Library/AcpiTimerLib/AcpiTimerLib.inf
 
 [PcdsPatchableInModule]
   gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel         | 0x8000004F
@@ -85,11 +90,9 @@
   gPayloadTokenSpaceGuid.PcdPayloadHeapSize                | 0x02000000
   gPayloadTokenSpaceGuid.PcdPayloadStackSize               | 0x00010000
 
-
 [Components]
   PayloadPkg/HelloWorld/HelloWorld.inf
 
-
 [BuildOptions.Common.EDKII]
   # Enable link-time optimization when building with GCC49
   *_GCC49_IA32_CC_FLAGS = -flto