OcDataHubLib: Specify non 24 MHz ARTFrequency to macOS

Include/Library/OcCpuLib.h

@@ -75,9 +75,9 @@ typedef struct {
   // If unreported, the frequency is looked up based on the model and family.
   //
   // Nominal Core Crystal Clock Frequency for known processor families:
-  //   Intel Xeon Scalable with CPUID signature 0x0655: 25 Mhz
-  //   6th and 7th generation Intel Core & Xeon W: 24 Mhz
-  //   Nex Generation Intel Atom with CPUID 0x065C: 19.2 Mhz
+  //   Intel Xeon Scalable with CPUID signature 0x0655: 25 Mhz     (server segment)
+  //   6th and 7th generation Intel Core & Xeon W:      24 Mhz     (client segment)
+  //   Nex Generation Intel Atom with CPUID 0x065C:     19.2 Mhz   (atom segment)
   //
   UINT64                  ARTFrequency;
 

Include/ProcessorInfo.h

@@ -21,9 +21,15 @@
 
 #define BASE_NHM_CLOCK_SOURCE  133333333ULL
 
+//
 // Skylake bus clock is fixed at 100MHz
+// This constant is also known as BASE_ART_CLOCK_SOURCE in XNU
+//
+#define CLIENT_ART_CLOCK_SOURCE   24000000ULL
+#define SERVER_ART_CLOCK_SOURCE   25000000ULL
+#define ATOM_ART_CLOCK_SOURCE     19200000ULL
 
-#define BASE_ART_CLOCK_SOURCE  24000000ULL
+#define DEFAULT_ART_CLOCK_SOURCE  CLIENT_ART_CLOCK_SOURCE
 
 #define MSR_PIC_MSG_CONTROL       0x2E
 #define MSR_CORE_THREAD_COUNT     0x35

Library/OcCpuLib/OcCpuLib.c

@@ -692,13 +692,13 @@ ScanIntelProcessor (
         case CPU_MODEL_SKYLAKE_DT:
         case CPU_MODEL_KABYLAKE:
         case CPU_MODEL_KABYLAKE_DT:
-          Cpu->ARTFrequency = 24000000ULL; // 24 Mhz
+          Cpu->ARTFrequency = CLIENT_ART_CLOCK_SOURCE; // 24 Mhz
           break;
         case CPU_MODEL_DENVERTON:
-          Cpu->ARTFrequency = 25000000ULL; // 25 Mhz
+          Cpu->ARTFrequency = SERVER_ART_CLOCK_SOURCE; // 25 Mhz
           break;
         case CPU_MODEL_GOLDMONT:
-          Cpu->ARTFrequency = 19200000ULL; // 19.2 Mhz
+          Cpu->ARTFrequency = ATOM_ART_CLOCK_SOURCE; // 19.2 Mhz
           break;
       }
       if (Cpu->ARTFrequency > 0) {
@@ -736,7 +736,7 @@ ScanIntelProcessor (
       // it's 24 Mhz like most Intel chips to date.
       //
       if (Cpu->ARTFrequency == 0) {
-        Cpu->ARTFrequency = 24000000ULL; // 24 Mhz
+        Cpu->ARTFrequency = DEFAULT_ART_CLOCK_SOURCE;
         DEBUG ((DEBUG_INFO, "OCCPU: Fallback Core Crystal Clock Frequency %LuHz\n", Cpu->ARTFrequency));
       }
 

Library/OcDataHubLib/OcDataHubLib.c

@@ -14,6 +14,7 @@
 
 #include <Uefi.h>
 
+#include <ProcessorInfo.h>
 #include <IndustryStandard/Pci.h>
 
 #include <Guid/ApplePlatformInfo.h>
@@ -279,6 +280,9 @@ UpdateDataHub (
     Data->FSBFrequency = &CpuInfo->FSBFrequency;
   }
   DataHubSetAppleProcessorData (DataHub, OC_FSB_FREQUENCY, Data->FSBFrequency, sizeof (*Data->FSBFrequency));
+  if (Data->ARTFrequency == NULL && CpuInfo->ARTFrequency > 0 && CpuInfo->ARTFrequency != DEFAULT_ART_CLOCK_SOURCE) {
+    Data->ARTFrequency = &CpuInfo->ARTFrequency;
+  }
   DataHubSetAppleProcessorData (DataHub, OC_ART_FREQUENCY, Data->ARTFrequency, sizeof (*Data->ARTFrequency));
   DataHubSetAppleMiscData (DataHub, OC_DEVICE_PATHS_SUPPORTED, Data->DevicePathsSupported, sizeof (*Data->DevicePathsSupported));
   DataHubSetAppleMiscData (DataHub, OC_SMC_REVISION, Data->SmcRevision, OC_SMC_REVISION_SIZE);