diff --git a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
index 04ec17708b..b18f92d408 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
+++ b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
@@ -244,7 +244,7 @@ DxeMain (
   //
   // Initialize Debug Agent to support source level debug in DXE phase
   //
-  InitializeDebugAgent (DEBUG_AGENT_INIT_DXE_CORE, HobStart);
+  InitializeDebugAgent (DEBUG_AGENT_INIT_DXE_CORE, HobStart, NULL);
 
   //
   // Initialize Memory Services
diff --git a/MdeModulePkg/Include/Library/DebugAgentLib.h b/MdeModulePkg/Include/Library/DebugAgentLib.h
index 8424209091..f945b0c007 100644
--- a/MdeModulePkg/Include/Library/DebugAgentLib.h
+++ b/MdeModulePkg/Include/Library/DebugAgentLib.h
@@ -2,12 +2,12 @@
   Debug Agent Library provide source-level debug capability.
 
 Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
-This program and the accompanying materials are licensed and made available under 
-the terms and conditions of the BSD License that accompanies this distribution.  
+This program and the accompanying materials are licensed and made available under
+the terms and conditions of the BSD License that accompanies this distribution.
 The full text of the license may be found at
-http://opensource.org/licenses/bsd-license.php.                                            
+http://opensource.org/licenses/bsd-license.php.
 
-THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
 **/
@@ -22,21 +22,60 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #define DEBUG_AGENT_INIT_ENTER_SMI       5
 #define DEBUG_AGENT_INIT_EXIT_SMI        6
 #define DEBUG_AGENT_INIT_S3              7
+#define DEBUG_AGENT_INIT_DXE_AP          8
+
+
+//
+// Context for DEBUG_AGENT_INIT_POSTMEM_SEC
+//
+typedef struct {
+  UINTN          HeapMigrateOffset;
+  UINTN          StackMigrateOffset;
+} DEBUG_AGENT_CONTEXT_POSTMEM_SEC;
+
+/**
+  Caller provided function to be invoked at the end of InitializeDebugAgent().
+
+  Refer to the descrption for InitializeDebugAgent() for more details.
+
+  @param[in] Context    The first input parameter of InitializeDebugAgent().
+
+**/
+typedef
+VOID
+(EFIAPI * DEBUG_AGENT_CONTINUE)(
+  IN VOID        *Context
+  );
+
 
 /**
   Initialize debug agent.
 
-  This function is used to set up debug enviroment.
+  This function is used to set up debug environment to support source level debugging.
+  If certain Debug Agent Library instance has to save some private data in the stack,
+  this function must work on the mode that doesn't return to the caller, then
+  the caller needs to wrap up all rest of logic after InitializeDebugAgent() into one
+  function and pass it into InitializeDebugAgent(). InitializeDebugAgent() is
+  responsible to invoke the passing-in function at the end of InitializeDebugAgent().
 
-  @param[in] InitFlag   Init flag is used to decide the initialize process.
-  @param[in] Context    Context needed according to InitFlag; it was optional.
+  If the parameter Function is not NULL, Debug Agent Libary instance will invoke it by
+  passing in the Context to be its parameter.
+
+  If Function() is NULL, Debug Agent Library instance will return after setup debug
+  environment.
+
+  @param[in] InitFlag     Init flag is used to decide the initialize process.
+  @param[in] Context      Context needed according to InitFlag; it was optional.
+  @param[in] Function     Continue function called by debug agent library; it was
+                          optional.
 
 **/
 VOID
 EFIAPI
 InitializeDebugAgent (
   IN UINT32                InitFlag,
-  IN VOID                  *Context  OPTIONAL
+  IN VOID                  *Context, OPTIONAL
+  IN DEBUG_AGENT_CONTINUE  Function  OPTIONAL
   );
 
 /**
diff --git a/MdeModulePkg/Library/DebugAgentLibNull/DebugAgentLibNull.c b/MdeModulePkg/Library/DebugAgentLibNull/DebugAgentLibNull.c
index 0db1e866b6..09e1366189 100644
--- a/MdeModulePkg/Library/DebugAgentLibNull/DebugAgentLibNull.c
+++ b/MdeModulePkg/Library/DebugAgentLibNull/DebugAgentLibNull.c
@@ -12,23 +12,41 @@
 
 **/
 
+#include <Library/DebugAgentLib.h>
+
 /**
   Initialize debug agent.
 
-  This function is used to set up debug enviroment. It may enable interrupts.
+  This function is used to set up debug environment to support source level debugging.
+  If certain Debug Agent Library instance has to save some private data in the stack,
+  this function must work on the mode that doesn't return to the caller, then
+  the caller needs to wrap up all rest of logic after InitializeDebugAgent() into one
+  function and pass it into InitializeDebugAgent(). InitializeDebugAgent() is
+  responsible to invoke the passing-in function at the end of InitializeDebugAgent().
 
-  @param[in] InitFlag   Init flag is used to decide initialize process.
-  @param[in] Context    Context needed according to InitFlag, it was optional.
+  If the parameter Function is not NULL, Debug Agent Libary instance will invoke it by
+  passing in the Context to be its parameter.
+
+  If Function() is NULL, Debug Agent Library instance will return after setup debug
+  environment.
+
+  @param[in] InitFlag     Init flag is used to decide the initialize process.
+  @param[in] Context      Context needed according to InitFlag; it was optional.
+  @param[in] Function     Continue function called by debug agent library; it was
+                          optional.
 
 **/
 VOID
 EFIAPI
 InitializeDebugAgent (
   IN UINT32                InitFlag,
-  IN VOID                  *Context  OPTIONAL
+  IN VOID                  *Context, OPTIONAL
+  IN DEBUG_AGENT_CONTINUE  Function  OPTIONAL
   )
 {
-
+  if (Function != NULL) {
+    Function (Context);
+  }
 }
 
 /**