OcCpuLib: Fix incorrect core/thread counts on Pentium M

Author: Goldfish64

Changelog.md

@@ -7,7 +7,8 @@ OpenCore Changelog
 - Fixed `BOOTx64.efi` and `BOOTIA32.efi` convention
 - Fixed SMBIOS handling with multiple memory arrays
 - Fixed memory array handle assignment on empty slots
-- Fixed CPUID patching on certain versions of macOS 10.4.10 and 10.4.11.
+- Fixed CPUID patching on certain versions of macOS 10.4.10 and 10.4.11
+- Fixed incorrect core/thread counts on Pentium M processors
 
 #### v0.6.2
 - Updated builtin firmware versions for SMBIOS and the rest

Include/Intel/IndustryStandard/ProcessorInfo.h

@@ -149,6 +149,7 @@ enum {
 #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_BANIAS         0x09  ///< Banias
 #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

Library/OcCpuLib/AppleCpuSupport.c

@@ -140,6 +140,7 @@ InternalDetectAppleProcessorType (
     //
     case CPU_MODEL_WILLAMETTE: // 0x01
     case CPU_MODEL_NORTHWOOD:  // 0x02
+    case CPU_MODEL_BANIAS:     // 0x09
     case CPU_MODEL_DOTHAN:     // 0x0D
     case CPU_MODEL_YONAH:      // 0x0E
       // IM41  (T2400/T2500), MM11 (Solo T1200 / Duo T2300/T2400),

Library/OcCpuLib/OcCpuLib.c

@@ -471,6 +471,13 @@ ScanIntelProcessor (
     Msr = AsmReadMsr64 (MSR_CORE_THREAD_COUNT);
     Cpu->CoreCount   = (UINT16)BitFieldRead64 (Msr, 16, 19);
     Cpu->ThreadCount = (UINT16)BitFieldRead64 (Msr, 0,  15);
+  } else if (Cpu->Model == CPU_MODEL_BANIAS || Cpu->Model == CPU_MODEL_DOTHAN) {
+    //
+    // Banias and Dothan (Pentium M and Celeron M) never had
+    // multiple cores or threads, and do not support the MSR below.
+    //
+    Cpu->CoreCount   = 0;
+    Cpu->ThreadCount = 0;
   } else {
     Msr = AsmReadMsr64 (MSR_CORE_THREAD_COUNT);
     Cpu->CoreCount   = (UINT16)BitFieldRead64 (Msr, 16, 31);