diff --git a/Include/Intel/IndustryStandard/ProcessorInfo.h b/Include/Intel/IndustryStandard/ProcessorInfo.h
index 0feaa1c8..d4f1813e 100755
--- a/Include/Intel/IndustryStandard/ProcessorInfo.h
+++ b/Include/Intel/IndustryStandard/ProcessorInfo.h
@@ -144,6 +144,11 @@ enum {
 #define K10_COFVID_STATUS  0xC0010071
 #define K10_PSTATE_STATUS  0xC0010064
 
+#define CPU_MODEL_WILLAMETTE     0x01  ///< Willamette, Foster
+#define CPU_MODEL_NORTHWOOD      0x02  ///< Northwood, Prestonia, Gallatin
+#define CPU_MODEL_PRESCOTT       0x03  ///< Prescott, Nocona, Cranford, Potomac
+#define CPU_MODEL_PRESCOTT_2M    0x04  ///< Prescott 2M, Smithfield, Irwindale, Paxville
+#define CPU_MODEL_CEDAR_MILL     0x06  ///< Cedar Mill, Presler, Tusla, Dempsey
 #define CPU_MODEL_DOTHAN         0x0D  ///< Dothan
 #define CPU_MODEL_YONAH          0x0E  ///< Sossaman, Yonah
 #define CPU_MODEL_MEROM          0x0F  ///< Allendale, Conroe, Kentsfield, Woodcrest, Clovertown, Tigerton, Merom
diff --git a/Library/OcCpuLib/AppleCpuSupport.c b/Library/OcCpuLib/AppleCpuSupport.c
index f57c3fc5..72927959 100644
--- a/Library/OcCpuLib/AppleCpuSupport.c
+++ b/Library/OcCpuLib/AppleCpuSupport.c
@@ -117,31 +117,48 @@ InternalDetectAppleMajorType (
 
 UINT16
 InternalDetectAppleProcessorType (
-  IN UINT8  Model,
-  IN UINT8  Stepping,
-  IN UINT8  AppleMajorType,
-  IN UINT16 CoreCount
+  IN UINT8   Model,
+  IN UINT8   Stepping,
+  IN UINT8   AppleMajorType,
+  IN UINT16  CoreCount,
+  IN BOOLEAN Is64Bit
   )
 {
   switch (Model) {
     //
-    // Yonah: https://en.wikipedia.org/wiki/Yonah_(microprocessor)#Models_and_brand_names
+    // Willamette: https://en.wikipedia.org/wiki/Pentium_4#Willamette
+    // Northwood:  same page.
+    // Yonah:      https://en.wikipedia.org/wiki/Yonah_(microprocessor)#Models_and_brand_names
     //
     // Used by Apple:
     //   Core Duo, Core Solo
     //
-    // NOT used by Apple:
+    // Not used by Apple:
     //   Pentium, Celeron
     //
     // All 0x0201.
     //
-    case CPU_MODEL_DOTHAN: // 0x0D
-    case CPU_MODEL_YONAH:  // 0x0E
+    case CPU_MODEL_WILLAMETTE: // 0x01
+    case CPU_MODEL_NORTHWOOD:  // 0x02
+    case CPU_MODEL_DOTHAN:     // 0x0D
+    case CPU_MODEL_YONAH:      // 0x0E
       // IM41  (T2400/T2500), MM11 (Solo T1200 / Duo T2300/T2400),
       // MBP11 (L2400/T2400/T2500/T2600), MBP12 (T2600),
       // MB11  (T2400/T2500)
       return AppleProcessorTypeCoreSolo; // 0x0201
 
+    //
+    // Prescott:    https://en.wikipedia.org/wiki/Pentium_4#Prescott
+    // Prescott-2M: same page.
+    // Cedar Mill:  same page.
+    //
+    // Not used by Apple.
+    //
+    case CPU_MODEL_PRESCOTT:    // 0x03
+    case CPU_MODEL_PRESCOTT_2M: // 0x04
+    case CPU_MODEL_CEDAR_MILL:  // 0x06
+      return Is64Bit ? AppleProcessorTypeCore2DuoType1 : AppleProcessorTypeCoreSolo; // 0x0301 if 64-bit, otherwise 0x0201
+
     //
     // Merom:  https://en.wikipedia.org/wiki/Merom_(microprocessor)#Variants
     // Penryn: https://en.wikipedia.org/wiki/Penryn_(microprocessor)#Variants
diff --git a/Library/OcCpuLib/OcCpuInternals.h b/Library/OcCpuLib/OcCpuInternals.h
index 0d3aa452..c284e12e 100755
--- a/Library/OcCpuLib/OcCpuInternals.h
+++ b/Library/OcCpuLib/OcCpuInternals.h
@@ -60,6 +60,7 @@ InternalDetectAppleMajorType (
   @param[in] Stepping        CPU stepping from CPUID.
   @param[in] AppleMajorType  Apple CPU major type.
   @param[in] CoreCount       Number of physical cores.
+  @param[in] Is64Bit         CPU supports 64-bit mode.
 
   @retval Apple CPU type.
 **/
@@ -68,7 +69,8 @@ InternalDetectAppleProcessorType (
   IN UINT8  Model,
   IN UINT8  Stepping,
   IN UINT8  AppleMajorType,
-  IN UINT16 CoreCount
+  IN UINT16 CoreCount,
+  IN BOOLEAN Is64Bit
   );
 
 /**
diff --git a/Library/OcCpuLib/OcCpuLib.c b/Library/OcCpuLib/OcCpuLib.c
index 295e5155..769b8ba7 100755
--- a/Library/OcCpuLib/OcCpuLib.c
+++ b/Library/OcCpuLib/OcCpuLib.c
@@ -279,7 +279,13 @@ ScanIntelProcessorApple (
   UINT8  AppleMajorType;
 
   AppleMajorType = InternalDetectAppleMajorType (Cpu->BrandString);
-  Cpu->AppleProcessorType = InternalDetectAppleProcessorType (Cpu->Model, Cpu->Stepping, AppleMajorType, Cpu->CoreCount);
+  Cpu->AppleProcessorType = InternalDetectAppleProcessorType (
+                              Cpu->Model,
+                              Cpu->Stepping,
+                              AppleMajorType,
+                              Cpu->CoreCount,
+                              (Cpu->ExtFeatures & CPUID_EXTFEATURE_EM64T) != 0
+                              );
 
   DEBUG ((DEBUG_INFO, "OCCPU: Detected Apple Processor Type: %02X -> %04X\n", AppleMajorType, Cpu->AppleProcessorType));
 }