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

@@ -53,8 +53,10 @@
 
 #include <assert.h>
 #include "devices\Xbox.h" // For g_PCIBus
+#include <atomic>
 
 extern uint32_t GetAPUTime();
+extern std::atomic_bool g_bEnableAllInterrupts;
 
 //
 // Read & write handlers handlers for I/O
@@ -1012,6 +1014,16 @@ bool EmuX86_Opcode_TEST(LPEXCEPTION_POINTERS e, _DInst& info)
 	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)
 {
 	unsigned int decodedInstructionsCount = 0;
@@ -1116,6 +1128,16 @@ bool EmuX86_DecodeException(LPEXCEPTION_POINTERS e)
 		// Chase: Hollywood Stunt Driver hits this
 		EmuWarning("WRMSR instruction ignored");
 		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

@@ -1092,6 +1092,14 @@ uint32_t OHCI::OHCI_ReadRegister(xbaddr Addr)
 				ret = m_Registers.RhPort[1].HcRhPortStatus | OHCI_PORT_PPS;
 				break;
 
+			case 23:
+				ret = 0;
+				break;
+
+			case 24:
+				ret = 0;
+				break;
+
 			default:
 				EmuWarning("%s: Read register operation with bad offset %u. Ignoring.", LOG_STR_OHCI, Addr >> 2);
 		}
@@ -1223,6 +1231,12 @@ void OHCI::OHCI_WriteRegister(xbaddr Addr, uint32_t Value)
 				OHCI_PortSetStatus(1, Value);
 				break;
 
+			case 23:
+				break;
+
+			case 24:
+				break;
+
 			default:
 				EmuWarning("%s: Write register operation with bad offset %u. Ignoring.", LOG_STR_OHCI, Addr >> 2);
 		}