Added CLI and STI instruction support to EmuX86. Fixes a crash in ohci dpc routine

src/CxbxKrnl/CxbxKrnl.cpp

@@ -108,6 +108,9 @@ bool g_bIsRetail = false;
 DWORD_PTR g_CPUXbox = 0;
 DWORD_PTR g_CPUOthers = 0;
 
+// Indicates to enable/disable all interrupts when cli and sti instructions are executed
+std::atomic_bool g_bEnableAllInterrupts = true;
+
 // Set by the VMManager during initialization. Exported because it's needed in other parts of the emu
 size_t g_SystemMaxMemory = 0;
 
@@ -668,7 +671,7 @@ static unsigned int WINAPI CxbxKrnlInterruptThread(PVOID param)
 	InitSoftwareInterrupts();
 #endif
 
-	while (true) {
+	while (g_bEnableAllInterrupts) {
 		TriggerPendingConnectedInterrupts();
 		Sleep(1);
 	}

src/CxbxKrnl/EmuX86.cpp

@@ -52,9 +52,11 @@
 #include "HLEIntercept.h" // for bLLE_GPU
 
 #include <assert.h>
-#include "devices\Xbox.h" // For g_PCIBus
+#include "devices\Xbox.h" // For g_PCIBus
+#include <atomic>
 
-extern uint32_t GetAPUTime();
+extern uint32_t GetAPUTime();
+extern std::atomic_bool g_bEnableAllInterrupts;
 
 //
 // Read & write handlers handlers for I/O
@@ -1010,6 +1012,16 @@ bool EmuX86_Opcode_TEST(LPEXCEPTION_POINTERS e, _DInst& info)
 	// result is thrown away
 
 	return true;
+}
+
+void EmuX86_Opcode_CLI()
+{
+	g_bEnableAllInterrupts = false;
+}
+
+void EmuX86_Opcode_STI()
+{
+	g_bEnableAllInterrupts = true;
 }
 
 bool EmuX86_DecodeOpcode(const uint8_t *Eip, _DInst &info)
@@ -1115,7 +1127,17 @@ bool EmuX86_DecodeException(LPEXCEPTION_POINTERS e)
 		// This needs fixing eventually, but should be acceptible to ignore for now!
 		// Chase: Hollywood Stunt Driver hits this
 		EmuWarning("WRMSR instruction ignored");
-		break;
+		break;
+	case I_CLI: {
+		// Disable all interrupts
+		EmuX86_Opcode_CLI();
+		break;
+	}
+	case I_STI: {
+		// Enable all interrupts
+		EmuX86_Opcode_STI();
+		break;
+	}
 	default:
 		EmuWarning("Unhandled instruction : %u", info.opcode);
 		e->ContextRecord->Eip += info.size;

src/devices/usb/OHCI.cpp

@@ -1090,6 +1090,14 @@ uint32_t OHCI::OHCI_ReadRegister(xbaddr Addr)
 
 			case 22: // RhPort 1
 				ret = m_Registers.RhPort[1].HcRhPortStatus | OHCI_PORT_PPS;
+				break;
+
+			case 23:
+				ret = 0;
+				break;
+
+			case 24:
+				ret = 0;
 				break;
 
 			default:
@@ -1221,6 +1229,12 @@ void OHCI::OHCI_WriteRegister(xbaddr Addr, uint32_t Value)
 
 			case 22: // RhPort 1
 				OHCI_PortSetStatus(1, Value);
+				break;
+
+			case 23:
+				break;
+
+			case 24:
 				break;
 
 			default: