DuetPkg: Move EfiLdr Handoff data to stack

The EfiLdr image may be overwritten later in the boot process.
This can lead to the Handoff structure being corrupted before
DxeIpl is finished with it.

To help prevent this, we move the Handoff structure to the
stack, and in DxeIpl make a copy of it.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10950 6f19259b-4bc3-4df7-8a09-765794883524

DuetPkg/DxeIpl/DxeInit.c

@@ -138,6 +138,10 @@ Returns:
   VOID                  *MemoryDescriptor;
   VOID                  *NvStorageBase;
   CHAR8                 PrintBuffer[256];
+  EFILDRHANDOFF         HandoffCopy;
+
+  CopyMem ((VOID*) &HandoffCopy, (VOID*) Handoff, sizeof (EFILDRHANDOFF));
+  Handoff = &HandoffCopy;
 
   ClearScreen();
   PrintString("Enter DxeIpl ...\n");

DuetPkg/EfiLdr/EfiLoader.c

@@ -50,7 +50,7 @@ EfiLoader (
   UINTN                 BfvBase;
   EFI_MAIN_ENTRYPOINT   EfiMainEntrypoint;
   CHAR8                 PrintBuffer[256];
-  STATIC EFILDRHANDOFF  Handoff;
+  EFILDRHANDOFF         Handoff;
 
   ClearScreen();