HACK: Alternate method of handling Performance Counter

src/Cxbx/ResCxbx.h

@@ -112,6 +112,7 @@
 #define ID_FPS                          40096
 #define ID_HACKS_UNCAPFRAMERATE         40097
 #define ID_HACKS_RUNXBOXTHREADSONALLCORES         40098
+#define ID_HACKS_PATCHCPUFREQUENCY         40099		
 #define IDC_STATIC                      -1
 
 // Next default values for new objects

src/Cxbx/WndMain.cpp

@@ -190,6 +190,12 @@ WndMain::WndMain(HINSTANCE x_hInstance) :
 				m_UseAllCores = 0;
 			}
 
+			dwType = REG_DWORD; dwSize = sizeof(DWORD);
+			result = RegQueryValueEx(hKey, "HackPatchCpuFrequency", NULL, &dwType, (PBYTE)&m_PatchCpuFrequency, &dwSize);
+			if (result != ERROR_SUCCESS) {
+				m_PatchCpuFrequency = 0;
+			}
+
 			dwType = REG_DWORD; dwSize = sizeof(DWORD);
 			result = RegQueryValueEx(hKey, "CxbxDebug", NULL, &dwType, (PBYTE)&m_CxbxDebug, &dwSize);
 			if (result != ERROR_SUCCESS) {
@@ -349,6 +355,9 @@ WndMain::~WndMain()
 			dwType = REG_DWORD; dwSize = sizeof(DWORD);
 			RegSetValueEx(hKey, "HackUseAllCores", 0, dwType, (PBYTE)&m_UseAllCores, dwSize);
 
+			dwType = REG_DWORD; dwSize = sizeof(DWORD);
+			RegSetValueEx(hKey, "HackPatchCpuFrequency", 0, dwType, (PBYTE)&m_PatchCpuFrequency, dwSize);
+
 			dwType = REG_DWORD; dwSize = sizeof(DWORD);
             RegSetValueEx(hKey, "CxbxDebug", 0, dwType, (PBYTE)&m_CxbxDebug, dwSize);
 
@@ -1311,6 +1320,10 @@ LRESULT CALLBACK WndMain::WndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lP
 				RefreshMenus();
 				break;
 
+			case ID_HACKS_PATCHCPUFREQUENCY:
+				m_PatchCpuFrequency = !m_PatchCpuFrequency;
+				RefreshMenus();
+				break;
 
             case ID_HELP_ABOUT:
             {
@@ -1739,6 +1752,9 @@ void WndMain::RefreshMenus()
 
 			chk_flag = (m_UseAllCores) ? MF_CHECKED : MF_UNCHECKED;
 			CheckMenuItem(settings_menu, ID_HACKS_RUNXBOXTHREADSONALLCORES, chk_flag);
+
+			chk_flag = (m_PatchCpuFrequency) ? MF_CHECKED : MF_UNCHECKED;
+			CheckMenuItem(settings_menu, ID_HACKS_PATCHCPUFREQUENCY, chk_flag);	
 		}
 
         // emulation menu
@@ -2112,6 +2128,7 @@ void WndMain::StartEmulation(HWND hwndParent, DebuggerState LocalDebuggerState /
 	g_EmuShared->SetDisablePixelShaders(&m_DisablePixelShaders);
 	g_EmuShared->SetUncapFramerate(&m_UncapFramerate);
 	g_EmuShared->SetUseAllCores(&m_UseAllCores);
+	g_EmuShared->SetPatchCpuFrequency(&m_PatchCpuFrequency);
 
 	// shell exe
     {

src/Cxbx/WndMain.h

@@ -216,6 +216,7 @@ class WndMain : public Wnd
 		int		m_DisablePixelShaders;
 		int		m_UncapFramerate;
 		int		m_UseAllCores;
+		int		m_PatchCpuFrequency;
 
         // ******************************************************************
         // * debug output filenames

src/CxbxKrnl/CxbxKrnl.cpp

@@ -579,6 +579,7 @@ void PrintCurrentConfigurationLog()
 		printf("Disable Pixel Shaders: %s\n", g_DisablePixelShaders == 1 ? "On" : "Off");
 		printf("Uncap Framerate: %s\n", g_UncapFramerate == 1 ? "On" : "Off");
 		printf("Run Xbox threads on all cores: %s\n", g_UseAllCores == 1 ? "On" : "Off");
+		printf("Patch CPU Frequency (rdtsc): %s\n", g_PatchCpuFrequency == 1 ? "On" : "Off");
 	}
 
 	printf("------------------------- END OF CONFIG LOG ------------------------\n");
@@ -648,6 +649,38 @@ static unsigned int WINAPI CxbxKrnlInterruptThread(PVOID param)
 	return 0;
 }
 
+void PatchPerformanceFrequency()
+{
+	DWORD xboxFrequency = 733333333; // 733mhz
+	LARGE_INTEGER hostFrequency;
+	QueryPerformanceFrequency(&hostFrequency);
+
+	DbgPrintf("INIT: Patching FS Register Accesses\n");
+	DWORD sizeOfImage = CxbxKrnl_XbeHeader->dwSizeofImage;
+
+	// Iterate through each CODE section
+	for (uint32 sectionIndex = 0; sectionIndex < CxbxKrnl_Xbe->m_Header.dwSections; sectionIndex++) {
+		if (!CxbxKrnl_Xbe->m_SectionHeader[sectionIndex].dwFlags.bExecutable) {
+			continue;
+		}
+
+		printf("INIT: Searching for xbox performance frequency in section %s\n", CxbxKrnl_Xbe->m_szSectionName[sectionIndex]);
+		xbaddr startAddr = CxbxKrnl_Xbe->m_SectionHeader[sectionIndex].dwVirtualAddr;
+		xbaddr endAddr = startAddr + CxbxKrnl_Xbe->m_SectionHeader[sectionIndex].dwSizeofRaw;
+		for (xbaddr addr = startAddr; addr < endAddr; addr++)
+		{
+			if (memcmp((void*)addr, &xboxFrequency, sizeof(DWORD)) == 0) {
+				printf("INIT: Patching Frequency at 0x%.8X\n", addr);
+				*(uint32*)(addr + 1) = (uint32)hostFrequency.QuadPart;
+				addr += sizeof(DWORD);
+				break;
+			}
+		}
+	}
+
+	printf("INIT: Done patching xbox performance frequency\n");
+}
+
 void CxbxKrnlMain(int argc, char* argv[])
 {
 	// Skip '/load' switch
@@ -1039,6 +1072,8 @@ __declspec(noreturn) void CxbxKrnlInit
 		g_UncapFramerate = !!HackEnabled;
 		g_EmuShared->GetUseAllCores(&HackEnabled);
 		g_UseAllCores = !!HackEnabled;
+		g_EmuShared->GetPatchCpuFrequency(&HackEnabled);
+		g_PatchCpuFrequency = !!HackEnabled;
 	}
 
 #ifdef _DEBUG_PRINT_CURRENT_CONF
@@ -1204,6 +1239,10 @@ __declspec(noreturn) void CxbxKrnlInit
 	// See: https://multimedia.cx/eggs/xbox-sphinx-protocol/
 	ApplyMediaPatches();
 
+	if (g_PatchCpuFrequency) {
+		PatchPerformanceFrequency();
+	}
+
 	// Setup per-title encryption keys
 	SetupPerTitleKeys();
 

src/CxbxKrnl/Emu.cpp

@@ -67,6 +67,7 @@ bool g_XInputEnabled = false;
 bool g_DisablePixelShaders = false;
 bool g_UncapFramerate = false;
 bool g_UseAllCores = false;
+bool g_PatchCpuFrequency = false;
 
 // Delta added to host SystemTime, used in xboxkrnl::KeQuerySystemTime and xboxkrnl::NtSetSystemTime
 LARGE_INTEGER	HostSystemTimeDelta = {};

src/CxbxKrnl/Emu.h

@@ -110,4 +110,5 @@ typedef struct DUMMY_KERNEL
 extern bool g_DisablePixelShaders;
 extern bool g_UncapFramerate;
 extern bool g_UseAllCores;
+extern bool g_PatchCpuFrequency;
 #endif

src/CxbxKrnl/EmuD3D8.cpp

@@ -215,11 +215,6 @@ g_EmuCDPD = {0};
 
 #endif
 
-// Declares an unpatched Xbox function trampoline, callable by name (with a 'XB_' prefix attached)
-#define XB_trampoline(ret, conv, name, arguments) \
-	typedef ret(conv *XB_##name##_t)arguments; \
-	static XB_##name##_t XB_##name = (XB_##name##_t)GetXboxFunctionPointer(#name);
-
 // TODO: This should be a D3DDevice structure
 DWORD* g_XboxD3DDevice;
 

src/CxbxKrnl/EmuKrnlKe.cpp

@@ -1096,6 +1096,11 @@ XBSYSAPI EXPORTNUM(126) xboxkrnl::ULONGLONG NTAPI xboxkrnl::KeQueryPerformanceCo
 	ULONGLONG ret;
 	::LARGE_INTEGER PerformanceCounter;
 
+	if (g_PatchCpuFrequency) {
+		RETURN((ULONGLONG)__rdtsc());
+	}
+
+
 	// TODO : When Cxbx emulates the RDTSC opcode, use the same handling here.
 
 	// Dxbx note : Xbox actually uses the RDTSC machine code instruction for this,

src/CxbxKrnl/EmuShared.h

@@ -126,6 +126,8 @@ class EmuShared : public Mutex
 		void SetUncapFramerate(int* value) { Lock(); m_UncapFramerate = *value; Unlock(); }
 		void GetUseAllCores(int* value) { Lock(); *value = m_UseAllCores; Unlock(); }
 		void SetUseAllCores(int* value) { Lock(); m_UseAllCores = *value; Unlock(); }
+		void GetPatchCpuFrequency(int* value) { Lock(); *value = m_PatchCpuFrequeny; Unlock(); }
+		void SetPatchCpuFrequency(int* value) { Lock(); m_PatchCpuFrequeny = *value; Unlock(); }
 
 		// ******************************************************************
 		// * MSpF/Benchmark values Accessors
@@ -194,6 +196,7 @@ class EmuShared : public Mutex
 		int			 m_DisablePixelShaders;
 		int			 m_UncapFramerate;
 		int			 m_UseAllCores;
+		int			 m_PatchCpuFrequeny;
 		float		 m_MSpF;
 		float        m_FPS;
 		bool		 m_bMultiXbeFlag;

src/CxbxKrnl/EmuXapi.cpp

@@ -940,6 +940,11 @@ BOOL WINAPI XTL::EMUPATCH(QueryPerformanceCounter)
 {
 	FUNC_EXPORTS;
 
+	if (g_PatchCpuFrequency) {
+		lpPerformanceCount->QuadPart = (LONGLONG)__rdtsc();
+		return TRUE;
+	}
+
 	lpPerformanceCount->QuadPart = xboxkrnl::KeQueryPerformanceCounter();
 	return TRUE;
 }

src/CxbxKrnl/HLEIntercept.h

@@ -47,6 +47,11 @@ void EmuHLEIntercept(Xbe::Header *XbeHeader);
 std::string GetDetectedSymbolName(xbaddr address, int *symbolOffset);
 void* GetXboxFunctionPointer(std::string functionName);
 
+// Declares an unpatched Xbox function trampoline, callable by name (with a 'XB_' prefix attached)
+#define XB_trampoline(ret, conv, name, arguments) \
+	typedef ret(conv *XB_##name##_t)arguments; \
+	static XB_##name##_t XB_##name = (XB_##name##_t)GetXboxFunctionPointer(#name);
+
 #ifdef _DEBUG_TRACE
 void VerifyHLEDataBase();
 #endif