Index: OvmfPkg/PlatformPei/MemDetect.c
===================================================================
--- OvmfPkg/PlatformPei/MemDetect.c	(revision 9332)
+++ OvmfPkg/PlatformPei/MemDetect.c	(working copy)
@@ -34,12 +34,12 @@
 #include "Cmos.h"
 
 STATIC
-UINTN
+UINT64
 GetSystemMemorySize (
   )
 {
-  UINT8 Cmos0x34;
-  UINT8 Cmos0x35;
+  UINT64 Cmos0x34;
+  UINT64 Cmos0x35;
 
   //
   // CMOS 0x34/0x35 specifies the system memory above 16 MB.
@@ -50,8 +50,8 @@
   //   into the calculation to get the total memory size.
   //
 
-  Cmos0x34 = (UINT8) CmosRead8 (0x34);
-  Cmos0x35 = (UINT8) CmosRead8 (0x35);
+  Cmos0x34 = CmosRead8(0x34);
+  Cmos0x35 = CmosRead8(0x35);
 
   return ((((Cmos0x35 << 8) + Cmos0x34) << 16) + SIZE_16MB);
 }
@@ -77,7 +77,7 @@
   //
   // Determine total memory size available
   //
-  TotalMemorySize = (UINT64)GetSystemMemorySize ();
+  TotalMemorySize = GetSystemMemorySize ();
 
   MemoryBase = 0x800000;
   MemorySize = TotalMemorySize - MemoryBase - 0x100000;