Cocoa Port: Give user feedback for when the emulation gets halted internally.

- Also be more consistent when recovering from an internal emulation halt.
- Also apply enabling the external BIOS, external firmware and firmware boot settings at load/reset time instead of at frame time.

desmume/src/MMU.cpp

@@ -1490,7 +1490,7 @@ void FASTCALL MMU_writeToSPIData(u16 val)
 					{
 						printf("SYSTEM POWERED OFF VIA ARM7 SPI POWER DEVICE\n");
 						printf("Did your main() return?\n");
-						emu_halt();
+						emu_halt(EMUHALT_REASON_SYSTEM_POWERED_OFF, NDSErrorTag_None);
 					}
 				}
 

desmume/src/NDSSystem.cpp

@@ -84,6 +84,7 @@ std::string InputDisplayString;
 
 static BOOL LidClosed = FALSE;
 static u8 countLid = 0;
+static NDSError _lastNDSError;
 
 GameInfo gameInfo;
 NDSSystem nds;
@@ -2663,6 +2664,10 @@ void NDS_Reset()
 
 	//this needs to happen last, pretty much, since it establishes the correct scheduling state based on all of the above initialization
 	initSchedule();
+	
+	_lastNDSError.code = NDSError_NoError;
+	_lastNDSError.tag = NDSErrorTag_None;
+	NDS_CurrentCPUInfoToNDSError(_lastNDSError);
 }
 
 static std::string MakeInputDisplayString(u16 pad, const std::string* Buttons, int count) {
@@ -3019,12 +3024,59 @@ void NDS_swapScreen()
 	}
 }
 
-
+NDSError NDS_GetLastError()
-void emu_halt()
 {
-	//printf("halting emu: ARM9 PC=%08X/%08X, ARM7 PC=%08X/%08X\n", NDS_ARM9.R[15], NDS_ARM9.instruct_adr, NDS_ARM7.R[15], NDS_ARM7.instruct_adr);
+	return _lastNDSError;
-	execute = false;
+}
+
+static void NDS_CurrentCPUInfoToNDSError(NDSError &ndsError)
+{
+	ndsError.programCounterARM9		= NDS_ARM9.R[15];
+	ndsError.instructionARM9		= NDS_ARM9.instruction;
+	ndsError.instructionAddrARM9	= NDS_ARM9.instruct_adr;
+	ndsError.programCounterARM7		= NDS_ARM7.R[15];
+	ndsError.instructionARM7		= NDS_ARM7.instruction;
+	ndsError.instructionAddrARM7	= NDS_ARM7.instruct_adr;
+}
+
+void emu_halt(EmuHaltReasonCode reasonCode, NDSErrorTag errorTag)
+{
+	switch (reasonCode)
+	{
+		case EMUHALT_REASON_USER_REQUESTED_HALT:
+			_lastNDSError.code = NDSError_NoError;
+			_lastNDSError.tag = NDSErrorTag_None;
+			break;
+			
+		case EMUHALT_REASON_SYSTEM_POWERED_OFF:
+			_lastNDSError.code = NDSError_SystemPoweredOff;
+			_lastNDSError.tag = NDSErrorTag_None;
+			break;
+			
+		case EMUHALT_REASON_JIT_UNMAPPED_ADDRESS_EXCEPTION:
+			_lastNDSError.code = NDSError_JITUnmappedAddressException;
+			_lastNDSError.tag = errorTag;
+			break;
+			
+		case EMUHALT_REASON_ARM_RESERVED_0X14_EXCEPTION:
+		case EMUHALT_REASON_ARM_UNDEFINED_INSTRUCTION_EXCEPTION:
+			_lastNDSError.code = NDSError_ARMUndefinedInstructionException;
+			_lastNDSError.tag = errorTag;
+			break;
+			
+		case EMUHALT_REASON_UNKNOWN:
+		default:
+			_lastNDSError.code = NDSError_UnknownError;
+			_lastNDSError.tag = errorTag;
+			break;
+	}
+	
+	NDS_CurrentCPUInfoToNDSError(_lastNDSError);
+	
 	GPU->ForceFrameStop();
+	execute = false;
+	
+	//printf("halting emu: ARM9 PC=%08X/%08X, ARM7 PC=%08X/%08X\n", NDS_ARM9.R[15], NDS_ARM9.instruct_adr, NDS_ARM7.R[15], NDS_ARM7.instruct_adr);
 	
 #ifdef LOG_ARM9
 	if (fp_dis9)

desmume/src/NDSSystem.h

@@ -82,6 +82,52 @@ enum
 	ROM_DSGBA
 };
 
+enum EmuHaltReasonCode
+{
+	EMUHALT_REASON_USER_REQUESTED_HALT					= 0,
+	
+	EMUHALT_REASON_SYSTEM_POWERED_OFF					= 1000,
+	
+	EMUHALT_REASON_JIT_UNMAPPED_ADDRESS_EXCEPTION		= 2000,
+	EMUHALT_REASON_ARM_RESERVED_0X14_EXCEPTION,
+	EMUHALT_REASON_ARM_UNDEFINED_INSTRUCTION_EXCEPTION,
+	
+	EMUHALT_REASON_UNKNOWN								= 10000
+};
+
+enum NDSErrorCode
+{
+	NDSError_NoError									= 0,
+	
+	NDSError_SystemPoweredOff							= 1000,
+	
+	NDSError_JITUnmappedAddressException				= 2000,
+	NDSError_ARMUndefinedInstructionException,
+	
+	NDSError_UnknownError								= 10000
+};
+
+enum NDSErrorTag
+{
+	NDSErrorTag_None		= 0,
+	NDSErrorTag_ARM9		= 1,
+	NDSErrorTag_ARM7		= 2,
+	NDSErrorTag_BothCPUs	= 3,
+};
+
+struct NDSError
+{
+	NDSErrorCode code;
+	NDSErrorTag tag;
+	u32 programCounterARM9;
+	u32 instructionARM9;
+	u32 instructionAddrARM9;
+	u32 programCounterARM7;
+	u32 instructionARM7;
+	u32 instructionAddrARM7;
+};
+typedef struct NDSError NDSError;
+
 //#define LOG_ARM9
 //#define LOG_ARM7
 
@@ -143,7 +189,9 @@ struct NDS_header
 #include "PACKED_END.h"
 
 extern void debug();
-void emu_halt();
+NDSError NDS_GetLastError();
+static void NDS_CurrentCPUInfoToNDSError(NDSError &ndsError);
+void emu_halt(EmuHaltReasonCode reasonCode, NDSErrorTag errorTag);
 
 extern u64 nds_timer;
 void NDS_Reschedule();

desmume/src/armcpu.cpp

@@ -498,7 +498,7 @@ void armcpu_exception(armcpu_t *cpu, u32 number)
 	case EXCEPTION_SWI: cpumode = SVC; break;
 	case EXCEPTION_PREFETCH_ABORT: cpumode = ABT; break;
 	case EXCEPTION_DATA_ABORT: cpumode = ABT; break;
-	case EXCEPTION_RESERVED_0x14: emu_halt(); break;
+	case EXCEPTION_RESERVED_0x14: emu_halt(EMUHALT_REASON_ARM_RESERVED_0X14_EXCEPTION, (cpu->proc_ID == ARMCPU_ARM9) ? NDSErrorTag_ARM9 : NDSErrorTag_ARM7); break;
 	case EXCEPTION_IRQ: cpumode = IRQ; break;
 	case EXCEPTION_FAST_IRQ: cpumode = FIQ; break;
 	}
@@ -576,7 +576,7 @@ u32 TRAPUNDEF(armcpu_t* cpu)
 	}
 	else
 	{
-		emu_halt();
+		emu_halt(EMUHALT_REASON_ARM_UNDEFINED_INSTRUCTION_EXCEPTION, (cpu->proc_ID == ARMCPU_ARM9) ? NDSErrorTag_ARM9 : NDSErrorTag_ARM7);
 		return 4;
 	}
 }

desmume/src/frontend/cocoa/ClientExecutionControl.cpp

@@ -379,20 +379,20 @@ void ClientExecutionControl::SetEnableGameSpecificHacks(bool enable)
 
 bool ClientExecutionControl::GetEnableExternalBIOS()
 {
-	pthread_mutex_lock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_lock(&this->_mutexSettingsPendingOnReset);
 	const bool enable = this->_settingsPending.enableExternalBIOS;
-	pthread_mutex_unlock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_unlock(&this->_mutexSettingsPendingOnReset);
 	
 	return enable;
 }
 
 void ClientExecutionControl::SetEnableExternalBIOS(bool enable)
 {
-	pthread_mutex_lock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_lock(&this->_mutexSettingsPendingOnReset);
 	this->_settingsPending.enableExternalBIOS = enable;
 	
-	this->_newSettingsPendingOnNDSExec = true;
+	this->_newSettingsPendingOnReset = true;
-	pthread_mutex_unlock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_unlock(&this->_mutexSettingsPendingOnReset);
 }
 
 bool ClientExecutionControl::GetEnableBIOSInterrupts()
@@ -433,38 +433,38 @@ void ClientExecutionControl::SetEnableBIOSPatchDelayLoop(bool enable)
 
 bool ClientExecutionControl::GetEnableExternalFirmware()
 {
-	pthread_mutex_lock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_lock(&this->_mutexSettingsPendingOnReset);
 	const bool enable = this->_settingsPending.enableExternalFirmware;
-	pthread_mutex_unlock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_unlock(&this->_mutexSettingsPendingOnReset);
 	
 	return enable;
 }
 
 void ClientExecutionControl::SetEnableExternalFirmware(bool enable)
 {
-	pthread_mutex_lock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_lock(&this->_mutexSettingsPendingOnReset);
 	this->_settingsPending.enableExternalFirmware = enable;
 	
-	this->_newSettingsPendingOnNDSExec = true;
+	this->_newSettingsPendingOnReset = true;
-	pthread_mutex_unlock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_unlock(&this->_mutexSettingsPendingOnReset);
 }
 
 bool ClientExecutionControl::GetEnableFirmwareBoot()
 {
-	pthread_mutex_lock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_lock(&this->_mutexSettingsPendingOnReset);
 	const bool enable = this->_settingsPending.enableFirmwareBoot;
-	pthread_mutex_unlock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_unlock(&this->_mutexSettingsPendingOnReset);
 	
 	return enable;
 }
 
 void ClientExecutionControl::SetEnableFirmwareBoot(bool enable)
 {
-	pthread_mutex_lock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_lock(&this->_mutexSettingsPendingOnReset);
 	this->_settingsPending.enableFirmwareBoot = enable;
 	
-	this->_newSettingsPendingOnNDSExec = true;
+	this->_newSettingsPendingOnReset = true;
-	pthread_mutex_unlock(&this->_mutexSettingsPendingOnNDSExec);
+	pthread_mutex_unlock(&this->_mutexSettingsPendingOnReset);
 }
 
 bool ClientExecutionControl::GetEnableDebugConsole()
@@ -710,6 +710,10 @@ void ClientExecutionControl::ApplySettingsOnReset()
 		this->_settingsApplied.filePathFirmware				= this->_settingsPending.filePathFirmware;
 		this->_settingsApplied.filePathSlot1R4				= this->_settingsPending.filePathSlot1R4;
 		
+		this->_settingsApplied.enableExternalBIOS			= this->_settingsPending.enableExternalBIOS;
+		this->_settingsApplied.enableExternalFirmware		= this->_settingsPending.enableExternalFirmware;
+		this->_settingsApplied.enableFirmwareBoot			= this->_settingsPending.enableFirmwareBoot;
+		
 		this->_settingsApplied.cpuEmulationEngineName		= this->_settingsPending.cpuEmulationEngineName;
 		this->_settingsApplied.slot1DeviceName				= this->_settingsPending.slot1DeviceName;
 		this->_ndsFrameInfo.cpuEmulationEngineName			= this->_settingsApplied.cpuEmulationEngineName;
@@ -726,6 +730,10 @@ void ClientExecutionControl::ApplySettingsOnReset()
 		
 		CommonSettings.use_jit					= (this->_settingsApplied.cpuEngineID == CPUEmulationEngineID_DynamicRecompiler);
 		CommonSettings.jit_max_block_size		= this->_settingsApplied.JITMaxBlockSize;
+		CommonSettings.UseExtBIOS				= this->_settingsApplied.enableExternalBIOS;
+		CommonSettings.UseExtFirmware			= this->_settingsApplied.enableExternalFirmware;
+		CommonSettings.UseExtFirmwareSettings	= this->_settingsApplied.enableExternalFirmware;
+		CommonSettings.BootFromFirmware			= this->_settingsApplied.enableFirmwareBoot;
 		
 		if (this->_settingsApplied.filePathARM9BIOS.length() == 0)
 		{
@@ -842,11 +850,8 @@ void ClientExecutionControl::ApplySettingsOnNDSExec()
 		this->_settingsApplied.enableAdvancedBusLevelTiming		= this->_settingsPending.enableAdvancedBusLevelTiming;
 		this->_settingsApplied.enableRigorous3DRenderingTiming	= this->_settingsPending.enableRigorous3DRenderingTiming;
 		this->_settingsApplied.enableGameSpecificHacks			= this->_settingsPending.enableGameSpecificHacks;
-		this->_settingsApplied.enableExternalBIOS				= this->_settingsPending.enableExternalBIOS;
 		this->_settingsApplied.enableBIOSInterrupts				= this->_settingsPending.enableBIOSInterrupts;
 		this->_settingsApplied.enableBIOSPatchDelayLoop			= this->_settingsPending.enableBIOSPatchDelayLoop;
-		this->_settingsApplied.enableExternalFirmware			= this->_settingsPending.enableExternalFirmware;
-		this->_settingsApplied.enableFirmwareBoot				= this->_settingsPending.enableFirmwareBoot;
 		this->_settingsApplied.enableDebugConsole				= this->_settingsPending.enableDebugConsole;
 		this->_settingsApplied.enableEnsataEmulation			= this->_settingsPending.enableEnsataEmulation;
 		
@@ -862,12 +867,8 @@ void ClientExecutionControl::ApplySettingsOnNDSExec()
 		
 		CommonSettings.advanced_timing			= this->_settingsApplied.enableAdvancedBusLevelTiming;
 		CommonSettings.rigorous_timing			= this->_settingsApplied.enableRigorous3DRenderingTiming;
-		CommonSettings.UseExtBIOS				= this->_settingsApplied.enableExternalBIOS;
 		CommonSettings.SWIFromBIOS				= this->_settingsApplied.enableBIOSInterrupts;
 		CommonSettings.PatchSWI3				= this->_settingsApplied.enableBIOSPatchDelayLoop;
-		CommonSettings.UseExtFirmware			= this->_settingsApplied.enableExternalFirmware;
-		CommonSettings.UseExtFirmwareSettings	= this->_settingsApplied.enableExternalFirmware;
-		CommonSettings.BootFromFirmware			= this->_settingsApplied.enableFirmwareBoot;
 		CommonSettings.DebugConsole				= this->_settingsApplied.enableDebugConsole;
 		CommonSettings.EnsataEmulation			= this->_settingsApplied.enableEnsataEmulation;
 		

desmume/src/frontend/cocoa/DeSmuME (XCode 3).xcodeproj/project.pbxproj

@@ -1422,6 +1422,11 @@
 		ABAE30BD1869484F00C92F4F /* Image_Piano.png in Resources */ = {isa = PBXBuildFile; fileRef = ABAE30BA1869484F00C92F4F /* Image_Piano.png */; };
 		ABAE30BE1869484F00C92F4F /* Image_Piano.png in Resources */ = {isa = PBXBuildFile; fileRef = ABAE30BA1869484F00C92F4F /* Image_Piano.png */; };
 		ABAE30BF1869484F00C92F4F /* Image_Piano.png in Resources */ = {isa = PBXBuildFile; fileRef = ABAE30BA1869484F00C92F4F /* Image_Piano.png */; };
+		ABAFD2751F7110E4007705BD /* gdbstub.cpp in Sources */ = {isa = PBXBuildFile; fileRef = ABD1FF171345ACA900AF11D1 /* gdbstub.cpp */; };
+		ABAFD2761F7110E4007705BD /* gdbstub.cpp in Sources */ = {isa = PBXBuildFile; fileRef = ABD1FF171345ACA900AF11D1 /* gdbstub.cpp */; };
+		ABAFD2771F7110E5007705BD /* gdbstub.cpp in Sources */ = {isa = PBXBuildFile; fileRef = ABD1FF171345ACA900AF11D1 /* gdbstub.cpp */; };
+		ABAFD2781F7110E5007705BD /* gdbstub.cpp in Sources */ = {isa = PBXBuildFile; fileRef = ABD1FF171345ACA900AF11D1 /* gdbstub.cpp */; };
+		ABAFD2791F7110E6007705BD /* gdbstub.cpp in Sources */ = {isa = PBXBuildFile; fileRef = ABD1FF171345ACA900AF11D1 /* gdbstub.cpp */; };
 		ABB6AD5D173A3F2B00EC2E8D /* Carbon.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = ABB6AD5C173A3F2B00EC2E8D /* Carbon.framework */; };
 		ABB9212117CEB4110049D4C5 /* slot1comp_protocol.cpp in Sources */ = {isa = PBXBuildFile; fileRef = ABB9212017CEB4110049D4C5 /* slot1comp_protocol.cpp */; };
 		ABB9212217CEB4110049D4C5 /* slot1comp_protocol.cpp in Sources */ = {isa = PBXBuildFile; fileRef = ABB9212017CEB4110049D4C5 /* slot1comp_protocol.cpp */; };
@@ -4611,6 +4616,7 @@
 				ABD4F2741F54A51000D75A1F /* ClientExecutionControl.cpp in Sources */,
 				ABC04DA41F67A20500EA6ED7 /* ClientInputHandler.cpp in Sources */,
 				ABC04DCB1F67A2AC00EA6ED7 /* macosx_10_5_compat.cpp in Sources */,
+				ABAFD2791F7110E6007705BD /* gdbstub.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -4798,6 +4804,7 @@
 				ABD4F2751F54A51000D75A1F /* ClientExecutionControl.cpp in Sources */,
 				ABC04DA51F67A20500EA6ED7 /* ClientInputHandler.cpp in Sources */,
 				ABC04DCC1F67A2AC00EA6ED7 /* macosx_10_5_compat.cpp in Sources */,
+				ABAFD2781F7110E5007705BD /* gdbstub.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -5015,6 +5022,7 @@
 				ABD4F2731F54A51000D75A1F /* ClientExecutionControl.cpp in Sources */,
 				ABC04DA31F67A20500EA6ED7 /* ClientInputHandler.cpp in Sources */,
 				ABC04DCA1F67A2AC00EA6ED7 /* macosx_10_5_compat.cpp in Sources */,
+				ABAFD2751F7110E4007705BD /* gdbstub.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -5232,6 +5240,7 @@
 				ABD4F2771F54A51000D75A1F /* ClientExecutionControl.cpp in Sources */,
 				ABC04DA71F67A20500EA6ED7 /* ClientInputHandler.cpp in Sources */,
 				ABC04DCE1F67A2AC00EA6ED7 /* macosx_10_5_compat.cpp in Sources */,
+				ABAFD2761F7110E4007705BD /* gdbstub.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -5419,6 +5428,7 @@
 				ABD4F2761F54A51000D75A1F /* ClientExecutionControl.cpp in Sources */,
 				ABC04DA61F67A20500EA6ED7 /* ClientInputHandler.cpp in Sources */,
 				ABC04DCD1F67A2AC00EA6ED7 /* macosx_10_5_compat.cpp in Sources */,
+				ABAFD2771F7110E5007705BD /* gdbstub.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -5625,6 +5635,7 @@
 				GCC_PREPROCESSOR_DEFINITIONS = (
 					_DEBUG,
 					"DEBUG=1",
+					GDB_STUB,
 				);
 				GCC_STRICT_ALIASING = YES;
 				GCC_SYMBOLS_PRIVATE_EXTERN = NO;

desmume/src/frontend/cocoa/cocoa_core.h

@@ -22,6 +22,9 @@
 #include <string>
 #import "cocoa_util.h"
 
+#include "../../NDSSystem.h"
+#undef BOOL
+
 
 class ClientExecutionControl;
 @class CocoaDSCore;
@@ -68,6 +71,7 @@ typedef struct
 	NSString *slot1StatusText;
 	NSString *frameStatus;
 	NSString *executionSpeedStatus;
+	NSString *errorStatus;
 	
 	OSSpinLock spinlockCdsController;
 	OSSpinLock spinlockMasterExecute;
@@ -115,6 +119,7 @@ typedef struct
 @property (assign) NSString *slot1StatusText;
 @property (assign) NSString *frameStatus;
 @property (assign) NSString *executionSpeedStatus;
+@property (retain) NSString *errorStatus;
 
 @property (copy) NSURL *arm9ImageURL;
 @property (copy) NSURL *arm7ImageURL;
@@ -146,6 +151,8 @@ typedef struct
 - (BOOL) startReplayRecording:(NSURL *)fileURL sramURL:(NSURL *)sramURL;
 - (void) stopReplay;
 
+- (void) postNDSError:(const NDSError &)ndsError;
+
 @end
 
 static void* RunCoreThread(void *arg);

desmume/src/frontend/cocoa/cocoa_core.mm

@@ -118,6 +118,7 @@ volatile bool execute = true;
 @synthesize slot1StatusText;
 @synthesize frameStatus;
 @synthesize executionSpeedStatus;
+@synthesize errorStatus;
 
 @dynamic arm9ImageURL;
 @dynamic arm7ImageURL;
@@ -207,6 +208,7 @@ volatile bool execute = true;
 	
 	frameStatus = @"---";
 	executionSpeedStatus = @"1.00x";
+	errorStatus = @"";
 	
 	return self;
 }
@@ -221,6 +223,7 @@ volatile bool execute = true;
 	[self setCdsFirmware:nil];
 	[self setCdsGPU:nil];
 	[self setCdsOutputList:nil];
+	[self setErrorStatus:nil];
 	
 	pthread_cancel(coreThread);
 	pthread_join(coreThread, NULL);
@@ -242,14 +245,23 @@ volatile bool execute = true;
 - (void) setMasterExecute:(BOOL)theState
 {
 	OSSpinLockLock(&spinlockMasterExecute);
-	execute = theState ? true : false;
+	
+	if (theState)
+	{
+		execute = true;
+	}
+	else
+	{
+		emu_halt(EMUHALT_REASON_UNKNOWN, NDSErrorTag_BothCPUs);
+	}
+	
 	OSSpinLockUnlock(&spinlockMasterExecute);
 }
 
 - (BOOL) masterExecute
 {
 	OSSpinLockLock(&spinlockMasterExecute);
-	const BOOL theState = execute ? YES : NO;
+	const BOOL theState = (execute) ? YES : NO;
 	OSSpinLockUnlock(&spinlockMasterExecute);
 	
 	return theState;
@@ -855,8 +867,8 @@ volatile bool execute = true;
 	pthread_mutex_unlock(&threadParam.mutexThreadExecute);
 	
 	[self updateSlot1DeviceStatus];
-	[self restoreCoreState];
 	[self setMasterExecute:YES];
+	[self restoreCoreState];
 	[[self cdsController] reset];
 	[[self cdsController] updateMicLevel];
 }
@@ -988,6 +1000,111 @@ volatile bool execute = true;
 	FCEUI_StopMovie();
 }
 
+- (void) postNDSError:(const NDSError &)ndsError
+{
+	NSString *newErrorString = nil;
+	
+	switch (ndsError.code)
+	{
+		case NDSError_NoError:
+			// Do nothing if there is no error.
+			return;
+			
+		case NDSError_SystemPoweredOff:
+			newErrorString = @"The system powered off using the ARM7 SPI device.";
+			break;
+			
+		case NDSError_JITUnmappedAddressException:
+		{
+			if (ndsError.tag == NDSErrorTag_ARM9)
+			{
+				newErrorString = [NSString stringWithFormat:
+@"JIT UNMAPPED ADDRESS EXCEPTION - ARM9:\n\
+\tARM9 Program Counter:     0x%08X\n\
+\tARM9 Instruction:         0x%08X\n\
+\tARM9 Instruction Address: 0x%08X",
+							  ndsError.programCounterARM9, ndsError.instructionARM9, ndsError.instructionAddrARM9];
+			}
+			else if (ndsError.tag == NDSErrorTag_ARM7)
+			{
+				newErrorString = [NSString stringWithFormat:
+@"JIT UNMAPPED ADDRESS EXCEPTION - ARM7:\n\
+\tARM7 Program Counter:     0x%08X\n\
+\tARM7 Instruction:         0x%08X\n\
+\tARM7 Instruction Address: 0x%08X",
+							  ndsError.programCounterARM7, ndsError.instructionARM7, ndsError.instructionAddrARM7];
+			}
+			else
+			{
+				newErrorString = [NSString stringWithFormat:
+@"JIT UNMAPPED ADDRESS EXCEPTION - UNKNOWN CPU:\n\
+\tARM9 Program Counter:     0x%08X\n\
+\tARM9 Instruction:         0x%08X\n\
+\tARM9 Instruction Address: 0x%08X\n\
+\tARM7 Program Counter:     0x%08X\n\
+\tARM7 Instruction:         0x%08X\n\
+\tARM7 Instruction Address: 0x%08X",
+							  ndsError.programCounterARM9, ndsError.instructionARM9, ndsError.instructionAddrARM9,
+							  ndsError.programCounterARM7, ndsError.instructionARM7, ndsError.instructionAddrARM7];
+			}
+			break;
+		}
+			
+		case NDSError_ARMUndefinedInstructionException:
+		{
+			if (ndsError.tag == NDSErrorTag_ARM9)
+			{
+				newErrorString = [NSString stringWithFormat:
+@"ARM9 UNDEFINED INSTRUCTION EXCEPTION:\n\
+\tARM9 Program Counter:     0x%08X\n\
+\tARM9 Instruction:         0x%08X\n\
+\tARM9 Instruction Address: 0x%08X",
+							  ndsError.programCounterARM9, ndsError.instructionARM9, ndsError.instructionAddrARM9];
+			}
+			else if (ndsError.tag == NDSErrorTag_ARM7)
+			{
+				newErrorString = [NSString stringWithFormat:
+@"ARM7 UNDEFINED INSTRUCTION EXCEPTION:\n\
+\tARM7 Program Counter:     0x%08X\n\
+\tARM7 Instruction:         0x%08X\n\
+\tARM7 Instruction Address: 0x%08X",
+							  ndsError.programCounterARM7, ndsError.instructionARM7, ndsError.instructionAddrARM7];
+			}
+			else
+			{
+				newErrorString = [NSString stringWithFormat:
+@"UNKNOWN ARM CPU UNDEFINED INSTRUCTION EXCEPTION:\n\
+\tARM9 Program Counter:     0x%08X\n\
+\tARM9 Instruction:         0x%08X\n\
+\tARM9 Instruction Address: 0x%08X\n\
+\tARM7 Program Counter:     0x%08X\n\
+\tARM7 Instruction:         0x%08X\n\
+\tARM7 Instruction Address: 0x%08X",
+							  ndsError.programCounterARM9, ndsError.instructionARM9, ndsError.instructionAddrARM9,
+							  ndsError.programCounterARM7, ndsError.instructionARM7, ndsError.instructionAddrARM7];
+			}
+			break;
+		}
+			
+		case NDSError_UnknownError:
+		default:
+			newErrorString = [NSString stringWithFormat:
+@"UNKNOWN ERROR:\n\
+\tARM9 Program Counter:     0x%08X\n\
+\tARM9 Instruction:         0x%08X\n\
+\tARM9 Instruction Address: 0x%08X\n\
+\tARM7 Program Counter:     0x%08X\n\
+\tARM7 Instruction:         0x%08X\n\
+\tARM7 Instruction Address: 0x%08X",
+							  ndsError.programCounterARM9, ndsError.instructionARM9, ndsError.instructionAddrARM9,
+							  ndsError.programCounterARM7, ndsError.instructionARM7, ndsError.instructionAddrARM7];
+			break;
+	}
+	
+	[self setErrorStatus:newErrorString];
+	[[NSNotificationCenter defaultCenter] postNotificationOnMainThreadName:@"org.desmume.DeSmuME.handleNDSError" object:self userInfo:nil];
+}
+
 @end
 
 static void* RunCoreThread(void *arg)
@@ -1039,9 +1156,10 @@ static void* RunCoreThread(void *arg)
 		// Check if an internal execution error occurred that halted the emulation.
 		if (!execute)
 		{
+			NDSError ndsError = NDS_GetLastError();
 			pthread_mutex_unlock(&param->mutexThreadExecute);
-			// TODO: Message the core that emulation halted.
+			
-			NSLog(@"The emulator halted during execution. Was it an internal error that caused this?");
+			[cdsCore postNDSError:ndsError];
 			continue;
 		}
 		

desmume/src/frontend/cocoa/translations/English.lproj/MainMenu.xib

@@ -12,6 +12,7 @@
     </object>
     <object class="NSMutableArray" key="IBDocument.EditedObjectIDs">
       <bool key="EncodedWithXMLCoder">YES</bool>
+      <integer value="10522"/>
     </object>
     <object class="NSArray" key="IBDocument.PluginDependencies">
       <bool key="EncodedWithXMLCoder">YES</bool>
@@ -1944,6 +1945,14 @@
                   <reference key="NSOnImage" ref="396634170"/>
                   <reference key="NSMixedImage" ref="678976864"/>
                 </object>
+                <object class="NSMenuItem" id="1030632434">
+                  <reference key="NSMenu" ref="664980152"/>
+                  <string key="NSTitle">Show GDB Stub Control...</string>
+                  <string key="NSKeyEquiv"/>
+                  <int key="NSMnemonicLoc">2147483647</int>
+                  <reference key="NSOnImage" ref="396634170"/>
+                  <reference key="NSMixedImage" ref="678976864"/>
+                </object>
                 <object class="NSMenuItem" id="306737379">
                   <reference key="NSMenu" ref="664980152"/>
                   <bool key="NSIsDisabled">YES</bool>
@@ -1954,9 +1963,9 @@
                   <reference key="NSOnImage" ref="396634170"/>
                   <reference key="NSMixedImage" ref="678976864"/>
                 </object>
-                <object class="NSMenuItem" id="1030632434">
+                <object class="NSMenuItem" id="469346871">
                   <reference key="NSMenu" ref="664980152"/>
-                  <string key="NSTitle">Show GDB Stub Control...</string>
+                  <string key="NSTitle">Disable Metal (requires app restart)</string>
                   <string key="NSKeyEquiv"/>
                   <int key="NSMnemonicLoc">2147483647</int>
                   <reference key="NSOnImage" ref="396634170"/>
@@ -1972,9 +1981,9 @@
                   <reference key="NSOnImage" ref="396634170"/>
                   <reference key="NSMixedImage" ref="678976864"/>
                 </object>
-                <object class="NSMenuItem" id="469346871">
+                <object class="NSMenuItem" id="329110847">
                   <reference key="NSMenu" ref="664980152"/>
-                  <string key="NSTitle">Disable Metal (requires app restart)</string>
+                  <string key="NSTitle">Simulate Emulation Crash</string>
                   <string key="NSKeyEquiv"/>
                   <int key="NSMnemonicLoc">2147483647</int>
                   <reference key="NSOnImage" ref="396634170"/>
@@ -13636,7 +13645,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
         <string key="NSWindowContentMaxSize">{1.7976931348623157e+308, 1.7976931348623157e+308}</string>
         <string key="NSWindowContentMinSize">{700, 250}</string>
         <object class="NSView" key="NSWindowView" id="731532737">
-          <nil key="NSNextResponder"/>
+          <reference key="NSNextResponder"/>
           <int key="NSvFlags">256</int>
           <object class="NSMutableArray" key="NSSubviews">
             <bool key="EncodedWithXMLCoder">YES</bool>
@@ -13645,6 +13654,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <int key="NSvFlags">268</int>
               <string key="NSFrame">{{17, 351}, {666, 34}}</string>
               <reference key="NSSuperview" ref="731532737"/>
+              <reference key="NSWindow"/>
               <bool key="NSEnabled">YES</bool>
               <object class="NSTextFieldCell" key="NSCell" id="497889808">
                 <int key="NSCellFlags">67108864</int>
@@ -13663,6 +13673,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <int key="NSvFlags">268</int>
               <string key="NSFrame">{{17, 351}, {666, 34}}</string>
               <reference key="NSSuperview" ref="731532737"/>
+              <reference key="NSWindow"/>
               <bool key="NSEnabled">YES</bool>
               <object class="NSTextFieldCell" key="NSCell" id="986675852">
                 <int key="NSCellFlags">67108864</int>
@@ -13681,6 +13692,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <int key="NSvFlags">289</int>
               <string key="NSFrame">{{362, 12}, {162, 32}}</string>
               <reference key="NSSuperview" ref="731532737"/>
+              <reference key="NSWindow"/>
               <int key="NSTag">2</int>
               <bool key="NSEnabled">YES</bool>
               <object class="NSButtonCell" key="NSCell" id="932208535">
@@ -13703,6 +13715,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <int key="NSvFlags">289</int>
               <string key="NSFrame">{{200, 12}, {162, 32}}</string>
               <reference key="NSSuperview" ref="731532737"/>
+              <reference key="NSWindow"/>
               <bool key="NSEnabled">YES</bool>
               <object class="NSButtonCell" key="NSCell" id="921528960">
                 <int key="NSCellFlags">67108864</int>
@@ -13724,6 +13737,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <int key="NSvFlags">268</int>
               <string key="NSFrame">{{17, 315}, {666, 28}}</string>
               <reference key="NSSuperview" ref="731532737"/>
+              <reference key="NSWindow"/>
               <bool key="NSEnabled">YES</bool>
               <object class="NSTextFieldCell" key="NSCell" id="389737972">
                 <int key="NSCellFlags">67108864</int>
@@ -13742,6 +13756,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <int key="NSvFlags">268</int>
               <string key="NSFrame">{{17, 315}, {666, 28}}</string>
               <reference key="NSSuperview" ref="731532737"/>
+              <reference key="NSWindow"/>
               <bool key="NSEnabled">YES</bool>
               <object class="NSTextFieldCell" key="NSCell" id="824504973">
                 <int key="NSCellFlags">67108864</int>
@@ -13760,6 +13775,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <int key="NSvFlags">292</int>
               <string key="NSFrame">{{18, 21}, {182, 18}}</string>
               <reference key="NSSuperview" ref="731532737"/>
+              <reference key="NSWindow"/>
               <bool key="NSEnabled">YES</bool>
               <object class="NSButtonCell" key="NSCell" id="548786511">
                 <int key="NSCellFlags">67108864</int>
@@ -13783,6 +13799,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <int key="NSvFlags">289</int>
               <string key="NSFrame">{{524, 12}, {162, 32}}</string>
               <reference key="NSSuperview" ref="731532737"/>
+              <reference key="NSWindow"/>
               <int key="NSTag">1</int>
               <bool key="NSEnabled">YES</bool>
               <object class="NSButtonCell" key="NSCell" id="283691405">
@@ -13815,6 +13832,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
                       <int key="NSvFlags">256</int>
                       <string key="NSFrameSize">{700, 229}</string>
                       <reference key="NSSuperview" ref="850501943"/>
+                      <reference key="NSWindow"/>
                       <string key="NSReuseIdentifierKey">_NS:1718</string>
                       <bool key="NSEnabled">YES</bool>
                       <bool key="NSAllowsLogicalLayoutDirection">NO</bool>
@@ -13824,14 +13842,14 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
                         <int key="NSvFlags">256</int>
                         <string key="NSFrameSize">{700, 17}</string>
                         <reference key="NSSuperview" ref="968198718"/>
+                        <reference key="NSWindow"/>
                         <string key="NSReuseIdentifierKey">_NS:1720</string>
                         <reference key="NSTableView" ref="796694466"/>
                       </object>
-                      <object class="_NSCornerView" key="NSCornerView" id="917215464">
+                      <object class="_NSCornerView" key="NSCornerView">
-                        <reference key="NSNextResponder" ref="266193397"/>
+                        <nil key="NSNextResponder"/>
                         <int key="NSvFlags">-2147483392</int>
                         <string key="NSFrame">{{224, 0}, {16, 17}}</string>
-                        <reference key="NSSuperview" ref="266193397"/>
                         <string key="NSReuseIdentifierKey">_NS:1724</string>
                       </object>
                       <object class="NSMutableArray" key="NSTableColumns">
@@ -13944,6 +13962,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
                   </object>
                   <string key="NSFrame">{{1, 17}, {700, 229}}</string>
                   <reference key="NSSuperview" ref="266193397"/>
+                  <reference key="NSWindow"/>
                   <reference key="NSNextKeyView" ref="796694466"/>
                   <string key="NSReuseIdentifierKey">_NS:1716</string>
                   <reference key="NSDocView" ref="796694466"/>
@@ -13955,6 +13974,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
                   <int key="NSvFlags">-2147483392</int>
                   <string key="NSFrame">{{224, 17}, {15, 102}}</string>
                   <reference key="NSSuperview" ref="266193397"/>
+                  <reference key="NSWindow"/>
                   <string key="NSReuseIdentifierKey">_NS:1741</string>
                   <bool key="NSAllowsLogicalLayoutDirection">NO</bool>
                   <reference key="NSTarget" ref="266193397"/>
@@ -13966,6 +13986,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
                   <int key="NSvFlags">-2147483392</int>
                   <string key="NSFrame">{{1, 197}, {700, 15}}</string>
                   <reference key="NSSuperview" ref="266193397"/>
+                  <reference key="NSWindow"/>
                   <string key="NSReuseIdentifierKey">_NS:1743</string>
                   <bool key="NSAllowsLogicalLayoutDirection">NO</bool>
                   <int key="NSsFlags">1</int>
@@ -13982,14 +14003,15 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
                   </object>
                   <string key="NSFrame">{{1, 0}, {700, 17}}</string>
                   <reference key="NSSuperview" ref="266193397"/>
+                  <reference key="NSWindow"/>
                   <reference key="NSNextKeyView" ref="650104671"/>
                   <string key="NSReuseIdentifierKey">_NS:1721</string>
                   <reference key="NSDocView" ref="650104671"/>
                 </object>
-                <reference ref="917215464"/>
               </object>
               <string key="NSFrame">{{-1, 60}, {702, 247}}</string>
               <reference key="NSSuperview" ref="731532737"/>
+              <reference key="NSWindow"/>
               <reference key="NSNextKeyView" ref="850501943"/>
               <string key="NSReuseIdentifierKey">_NS:1714</string>
               <int key="NSsFlags">133682</int>
@@ -14004,6 +14026,8 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
             </object>
           </object>
           <string key="NSFrameSize">{700, 405}</string>
+          <reference key="NSSuperview"/>
+          <reference key="NSWindow"/>
         </object>
         <string key="NSScreenRect">{{0, 0}, {1920, 1177}}</string>
         <string key="NSMinSize">{700, 272}</string>
@@ -14237,6 +14261,125 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
         <string key="NSMaxSize">{1.7976931348623157e+308, 1.7976931348623157e+308}</string>
         <bool key="NSWindowIsRestorable">YES</bool>
       </object>
+      <object class="NSWindowTemplate" id="292515803">
+        <int key="NSWindowStyleMask">1</int>
+        <int key="NSWindowBacking">2</int>
+        <string key="NSWindowRect">{{157, 347}, {400, 114}}</string>
+        <int key="NSWTFlags">1685586944</int>
+        <string key="NSWindowTitle">NDS Error</string>
+        <string key="NSWindowClass">NSWindow</string>
+        <nil key="NSViewClass"/>
+        <nil key="NSUserInterfaceItemIdentifier"/>
+        <object class="NSView" key="NSWindowView" id="13172379">
+          <reference key="NSNextResponder"/>
+          <int key="NSvFlags">256</int>
+          <object class="NSMutableArray" key="NSSubviews">
+            <bool key="EncodedWithXMLCoder">YES</bool>
+            <object class="NSTextField" id="487161905">
+              <reference key="NSNextResponder" ref="13172379"/>
+              <int key="NSvFlags">268</int>
+              <string key="NSFrame">{{17, 77}, {366, 17}}</string>
+              <reference key="NSSuperview" ref="13172379"/>
+              <string key="NSReuseIdentifierKey">_NS:3939</string>
+              <bool key="NSEnabled">YES</bool>
+              <object class="NSTextFieldCell" key="NSCell" id="194008675">
+                <int key="NSCellFlags">67108864</int>
+                <int key="NSCellFlags2">272891904</int>
+                <string key="NSContents">The emulation has halted due to an internal issue.</string>
+                <object class="NSFont" key="NSSupport">
+                  <string key="NSName">LucidaGrande-Bold</string>
+                  <double key="NSSize">13</double>
+                  <int key="NSfFlags">16</int>
+                </object>
+                <string key="NSCellIdentifier">_NS:3939</string>
+                <reference key="NSControlView" ref="487161905"/>
+                <reference key="NSBackgroundColor" ref="266180242"/>
+                <reference key="NSTextColor" ref="1045249657"/>
+              </object>
+              <bool key="NSAllowsLogicalLayoutDirection">NO</bool>
+              <int key="NSTextFieldAlignmentRectInsetsVersion">1</int>
+            </object>
+            <object class="NSButton" id="570766076">
+              <reference key="NSNextResponder" ref="13172379"/>
+              <int key="NSvFlags">289</int>
+              <string key="NSFrame">{{290, 12}, {96, 32}}</string>
+              <reference key="NSSuperview" ref="13172379"/>
+              <string key="NSReuseIdentifierKey">_NS:610</string>
+              <bool key="NSEnabled">YES</bool>
+              <object class="NSButtonCell" key="NSCell" id="774886600">
+                <int key="NSCellFlags">67108864</int>
+                <int key="NSCellFlags2">134217728</int>
+                <string key="NSContents">Stop</string>
+                <reference key="NSSupport" ref="462791774"/>
+                <string key="NSCellIdentifier">_NS:610</string>
+                <reference key="NSControlView" ref="570766076"/>
+                <int key="NSButtonFlags">-2038284288</int>
+                <int key="NSButtonFlags2">129</int>
+                <string key="NSAlternateContents"/>
+                <string type="base64-UTF8" key="NSKeyEquivalent">DQ</string>
+                <int key="NSPeriodicDelay">200</int>
+                <int key="NSPeriodicInterval">25</int>
+              </object>
+              <bool key="NSAllowsLogicalLayoutDirection">NO</bool>
+            </object>
+            <object class="NSButton" id="1020353354">
+              <reference key="NSNextResponder" ref="13172379"/>
+              <int key="NSvFlags">289</int>
+              <string key="NSFrame">{{194, 12}, {96, 32}}</string>
+              <reference key="NSSuperview" ref="13172379"/>
+              <string key="NSReuseIdentifierKey">_NS:610</string>
+              <int key="NSTag">2</int>
+              <bool key="NSEnabled">YES</bool>
+              <object class="NSButtonCell" key="NSCell" id="278466473">
+                <int key="NSCellFlags">67108864</int>
+                <int key="NSCellFlags2">134217728</int>
+                <string key="NSContents">Reset</string>
+                <reference key="NSSupport" ref="462791774"/>
+                <string key="NSCellIdentifier">_NS:610</string>
+                <reference key="NSControlView" ref="1020353354"/>
+                <int key="NSButtonFlags">-2038284288</int>
+                <int key="NSButtonFlags2">129</int>
+                <string key="NSAlternateContents"/>
+                <string key="NSKeyEquivalent"/>
+                <int key="NSPeriodicDelay">200</int>
+                <int key="NSPeriodicInterval">25</int>
+              </object>
+              <bool key="NSAllowsLogicalLayoutDirection">NO</bool>
+            </object>
+            <object class="NSTextField" id="987846881">
+              <reference key="NSNextResponder" ref="13172379"/>
+              <int key="NSvFlags">292</int>
+              <string key="NSFrame">{{17, 53}, {366, 16}}</string>
+              <reference key="NSSuperview" ref="13172379"/>
+              <string key="NSReuseIdentifierKey">_NS:3939</string>
+              <bool key="NSEnabled">YES</bool>
+              <object class="NSTextFieldCell" key="NSCell" id="510036545">
+                <int key="NSCellFlags">69206017</int>
+                <int key="NSCellFlags2">272760832</int>
+                <string key="NSContents"/>
+                <object class="NSFont" key="NSSupport" id="197589044">
+                  <string key="NSName">Monaco</string>
+                  <double key="NSSize">11</double>
+                  <int key="NSfFlags">16</int>
+                </object>
+                <string key="NSPlaceholderString">error string</string>
+                <string key="NSCellIdentifier">_NS:3939</string>
+                <reference key="NSControlView" ref="987846881"/>
+                <reference key="NSBackgroundColor" ref="266180242"/>
+                <reference key="NSTextColor" ref="1045249657"/>
+              </object>
+              <bool key="NSAllowsLogicalLayoutDirection">NO</bool>
+              <int key="NSTextFieldAlignmentRectInsetsVersion">1</int>
+            </object>
+          </object>
+          <string key="NSFrameSize">{400, 114}</string>
+          <reference key="NSSuperview"/>
+          <string key="NSReuseIdentifierKey">_NS:122</string>
+        </object>
+        <string key="NSScreenRect">{{0, 0}, {1440, 878}}</string>
+        <string key="NSMaxSize">{1.7976931348623157e+308, 1.7976931348623157e+308}</string>
+        <bool key="NSWindowIsRestorable">NO</bool>
+      </object>
       <object class="NSWindowTemplate" id="217226210">
         <int key="NSWindowStyleMask">7</int>
         <int key="NSWindowBacking">2</int>
@@ -15131,11 +15274,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
                           <int key="NSCellFlags">69206081</int>
                           <int key="NSCellFlags2">137216</int>
                           <string key="NSContents">Text Cell</string>
-                          <object class="NSFont" key="NSSupport" id="197589044">
+                          <reference key="NSSupport" ref="197589044"/>
-                            <string key="NSName">Monaco</string>
-                            <double key="NSSize">11</double>
-                            <int key="NSfFlags">16</int>
-                          </object>
                           <reference key="NSControlView" ref="1001428622"/>
                           <reference key="NSBackgroundColor" ref="856317944"/>
                           <reference key="NSTextColor" ref="1045249657"/>
@@ -30838,6 +30977,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           <string>frameJumpBehavior</string>
           <string>frameJumpNumberFramesForward</string>
           <string>frameJumpToFrameIndex</string>
+          <string>errorStatus</string>
         </object>
         <string key="NSObjectClassName">CocoaDSCore</string>
         <object class="_NSManagedProxy" key="_NSManagedProxy"/>
@@ -44538,6 +44678,82 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           </object>
           <int key="connectionID">10520</int>
         </object>
+        <object class="IBConnectionRecord">
+          <object class="IBOutletConnection" key="connection">
+            <string key="label">ndsErrorSheet</string>
+            <reference key="source" ref="231770064"/>
+            <reference key="destination" ref="292515803"/>
+          </object>
+          <int key="connectionID">10532</int>
+        </object>
+        <object class="IBConnectionRecord">
+          <object class="IBActionConnection" key="connection">
+            <string key="label">closeSheet:</string>
+            <reference key="source" ref="231770064"/>
+            <reference key="destination" ref="570766076"/>
+          </object>
+          <int key="connectionID">10533</int>
+        </object>
+        <object class="IBConnectionRecord">
+          <object class="IBActionConnection" key="connection">
+            <string key="label">closeSheet:</string>
+            <reference key="source" ref="231770064"/>
+            <reference key="destination" ref="1020353354"/>
+          </object>
+          <int key="connectionID">10534</int>
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+            <reference key="source" ref="987846881"/>
+            <reference key="destination" ref="582168938"/>
+            <object class="NSNibBindingConnector" key="connector">
+              <reference key="NSSource" ref="987846881"/>
+              <reference key="NSDestination" ref="582168938"/>
+              <string key="NSLabel">value: selection.errorStatus</string>
+              <string key="NSBinding">value</string>
+              <string key="NSKeyPath">selection.errorStatus</string>
+              <int key="NSNibBindingConnectorVersion">2</int>
+            </object>
+          </object>
+          <int key="connectionID">10535</int>
+        </object>
+        <object class="IBConnectionRecord">
+          <object class="IBOutletConnection" key="connection">
+            <string key="label">ndsErrorStatusTextField</string>
+            <reference key="source" ref="231770064"/>
+            <reference key="destination" ref="987846881"/>
+          </object>
+          <int key="connectionID">10536</int>
+        </object>
+        <object class="IBConnectionRecord">
+          <object class="IBActionConnection" key="connection">
+            <string key="label">simulateEmulationCrash:</string>
+            <reference key="source" ref="231770064"/>
+            <reference key="destination" ref="329110847"/>
+          </object>
+          <int key="connectionID">10537</int>
+        </object>
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+          <object class="IBBindingConnection" key="connection">
+            <string key="label">hidden: isDeveloperPlusBuild</string>
+            <reference key="source" ref="329110847"/>
+            <reference key="destination" ref="976324537"/>
+            <object class="NSNibBindingConnector" key="connector">
+              <reference key="NSSource" ref="329110847"/>
+              <reference key="NSDestination" ref="976324537"/>
+              <string key="NSLabel">hidden: isDeveloperPlusBuild</string>
+              <string key="NSBinding">hidden</string>
+              <string key="NSKeyPath">isDeveloperPlusBuild</string>
+              <object class="NSDictionary" key="NSOptions">
+                <string key="NS.key.0">NSValueTransformerName</string>
+                <string key="NS.object.0">NSNegateBoolean</string>
+              </object>
+              <int key="NSNibBindingConnectorVersion">2</int>
+            </object>
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+          <int key="connectionID">10539</int>
+        </object>
       </object>
       <object class="IBMutableOrderedSet" key="objectRecords">
         <object class="NSArray" key="orderedObjects">
@@ -46043,9 +46259,10 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <reference ref="217330860"/>
               <reference ref="406886317"/>
               <reference ref="306737379"/>
+              <reference ref="628276370"/>
               <reference ref="1030632434"/>
               <reference ref="469346871"/>
-              <reference ref="628276370"/>
+              <reference ref="329110847"/>
             </object>
             <reference key="parent" ref="963830043"/>
           </object>
@@ -56727,6 +56944,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <reference ref="731532737"/>
             </object>
             <reference key="parent" ref="0"/>
+            <string key="objectName">Window (Game Data Migration Assistant)</string>
           </object>
           <object class="IBObjectRecord">
             <int key="objectID">9706</int>
@@ -60510,6 +60728,89 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
             <reference key="object" ref="213745199"/>
             <reference key="parent" ref="728665305"/>
           </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10521</int>
+            <reference key="object" ref="329110847"/>
+            <reference key="parent" ref="664980152"/>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10522</int>
+            <reference key="object" ref="292515803"/>
+            <object class="NSMutableArray" key="children">
+              <bool key="EncodedWithXMLCoder">YES</bool>
+              <reference ref="13172379"/>
+            </object>
+            <reference key="parent" ref="0"/>
+            <string key="objectName">Window (NDS Error)</string>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10523</int>
+            <reference key="object" ref="13172379"/>
+            <object class="NSMutableArray" key="children">
+              <bool key="EncodedWithXMLCoder">YES</bool>
+              <reference ref="487161905"/>
+              <reference ref="987846881"/>
+              <reference ref="570766076"/>
+              <reference ref="1020353354"/>
+            </object>
+            <reference key="parent" ref="292515803"/>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10524</int>
+            <reference key="object" ref="487161905"/>
+            <object class="NSMutableArray" key="children">
+              <bool key="EncodedWithXMLCoder">YES</bool>
+              <reference ref="194008675"/>
+            </object>
+            <reference key="parent" ref="13172379"/>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10525</int>
+            <reference key="object" ref="194008675"/>
+            <reference key="parent" ref="487161905"/>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10526</int>
+            <reference key="object" ref="570766076"/>
+            <object class="NSMutableArray" key="children">
+              <bool key="EncodedWithXMLCoder">YES</bool>
+              <reference ref="774886600"/>
+            </object>
+            <reference key="parent" ref="13172379"/>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10527</int>
+            <reference key="object" ref="774886600"/>
+            <reference key="parent" ref="570766076"/>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10528</int>
+            <reference key="object" ref="1020353354"/>
+            <object class="NSMutableArray" key="children">
+              <bool key="EncodedWithXMLCoder">YES</bool>
+              <reference ref="278466473"/>
+            </object>
+            <reference key="parent" ref="13172379"/>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10529</int>
+            <reference key="object" ref="278466473"/>
+            <reference key="parent" ref="1020353354"/>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10530</int>
+            <reference key="object" ref="987846881"/>
+            <object class="NSMutableArray" key="children">
+              <bool key="EncodedWithXMLCoder">YES</bool>
+              <reference ref="510036545"/>
+            </object>
+            <reference key="parent" ref="13172379"/>
+          </object>
+          <object class="IBObjectRecord">
+            <int key="objectID">10531</int>
+            <reference key="object" ref="510036545"/>
+            <reference key="parent" ref="987846881"/>
+          </object>
         </object>
       </object>
       <object class="NSMutableDictionary" key="flattenedProperties">
@@ -60886,6 +61187,23 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           <string>10505.IBPluginDependency</string>
           <string>10508.IBPluginDependency</string>
           <string>10509.IBPluginDependency</string>
+          <string>10521.IBPluginDependency</string>
+          <string>10522.IBEditorWindowLastContentRect</string>
+          <string>10522.IBPluginDependency</string>
+          <string>10522.IBWindowTemplateEditedContentRect</string>
+          <string>10522.NSWindowTemplate.visibleAtLaunch</string>
+          <string>10523.IBPluginDependency</string>
+          <string>10524.IBPluginDependency</string>
+          <string>10524.IBViewBoundsToFrameTransform</string>
+          <string>10525.IBPluginDependency</string>
+          <string>10526.IBPluginDependency</string>
+          <string>10526.IBViewBoundsToFrameTransform</string>
+          <string>10527.IBPluginDependency</string>
+          <string>10528.IBPluginDependency</string>
+          <string>10528.IBViewBoundsToFrameTransform</string>
+          <string>10529.IBPluginDependency</string>
+          <string>10530.IBPluginDependency</string>
+          <string>10531.IBPluginDependency</string>
           <string>1113.IBPluginDependency</string>
           <string>1114.IBPluginDependency</string>
           <string>1115.IBPluginDependency</string>
@@ -61210,6 +61528,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           <string>3211.IBPluginDependency</string>
           <string>3213.IBPluginDependency</string>
           <string>3214.IBPluginDependency</string>
+          <string>3456.IBEditorWindowLastContentRect</string>
           <string>3456.IBPluginDependency</string>
           <string>3456.IBWindowTemplateEditedContentRect</string>
           <string>3456.NSWindowTemplate.visibleAtLaunch</string>
@@ -63066,6 +63385,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           <string>968.IBPluginDependency</string>
           <string>969.IBPluginDependency</string>
           <string>970.IBPluginDependency</string>
+          <string>9705.IBEditorWindowLastContentRect</string>
           <string>9705.IBPluginDependency</string>
           <string>9705.IBWindowTemplateEditedContentRect</string>
           <string>9705.NSWindowTemplate.visibleAtLaunch</string>
@@ -63879,6 +64199,29 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>{{617, 513}, {400, 114}}</string>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>{{617, 513}, {400, 114}}</string>
+          <boolean value="NO"/>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <object class="NSAffineTransform">
+            <bytes key="NSTransformStruct">P4AAAL+AAABBiAAAw3gAAA</bytes>
+          </object>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <object class="NSAffineTransform">
+            <bytes key="NSTransformStruct">P4AAAL+AAABDXQAAwpwAAA</bytes>
+          </object>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <object class="NSAffineTransform">
+            <bytes key="NSTransformStruct">P4AAAL+AAABDGAAAww4AAA</bytes>
+          </object>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
@@ -64369,7 +64712,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
-          <string>{{380, 836}, {512, 20}}</string>
+          <string>{{463, 836}, {512, 20}}</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
@@ -64398,8 +64741,9 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>{{741, 693}, {335, 163}}</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
-          <string>{{1241, 208}, {335, 163}}</string>
+          <string>{{741, 693}, {335, 163}}</string>
           <boolean value="NO"/>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
@@ -65509,7 +65853,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
-          <string>{{598, 723}, {292, 113}}</string>
+          <string>{{787, 703}, {292, 133}}</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <reference ref="0"/>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
@@ -67105,8 +67449,9 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
+          <string>{{0, 429}, {700, 405}}</string>
           <string>com.apple.InterfaceBuilder.CocoaPlugin</string>
-          <string>{{189, 422}, {700, 405}}</string>
+          <string>{{0, 429}, {700, 405}}</string>
           <boolean value="NO"/>
           <boolean value="YES"/>
           <string>{700, 250}</string>
@@ -67290,7 +67635,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
         </object>
       </object>
       <nil key="sourceID"/>
-      <int key="maxID">10520</int>
+      <int key="maxID">10539</int>
     </object>
     <object class="IBClassDescriber" key="IBDocument.Classes">
       <object class="NSMutableArray" key="referencedPartialClassDescriptions">
@@ -68186,6 +68531,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <string>saveEmuSaveStateAs:</string>
               <string>saveEmuSaveStateSlot:</string>
               <string>setVerticalSyncForNonLayerBackedViews:</string>
+              <string>simulateEmulationCrash:</string>
               <string>slot1Eject:</string>
               <string>stopReplay:</string>
               <string>toggleAllDisplays:</string>
@@ -68254,6 +68600,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <string>id</string>
               <string>id</string>
               <string>id</string>
+              <string>id</string>
             </object>
           </object>
           <object class="NSMutableDictionary" key="actionInfosByName">
@@ -68297,6 +68644,7 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <string>saveEmuSaveStateAs:</string>
               <string>saveEmuSaveStateSlot:</string>
               <string>setVerticalSyncForNonLayerBackedViews:</string>
+              <string>simulateEmulationCrash:</string>
               <string>slot1Eject:</string>
               <string>stopReplay:</string>
               <string>toggleAllDisplays:</string>
@@ -68462,6 +68810,10 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
                 <string key="name">setVerticalSyncForNonLayerBackedViews:</string>
                 <string key="candidateClassName">id</string>
               </object>
+              <object class="IBActionInfo">
+                <string key="name">simulateEmulationCrash:</string>
+                <string key="candidateClassName">id</string>
+              </object>
               <object class="IBActionInfo">
                 <string key="name">slot1Eject:</string>
                 <string key="candidateClassName">id</string>
@@ -68537,6 +68889,8 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <string>exportRomSavePanelAccessoryView</string>
               <string>firmwarePanelController</string>
               <string>inputManager</string>
+              <string>ndsErrorSheet</string>
+              <string>ndsErrorStatusTextField</string>
               <string>romInfoPanelController</string>
               <string>saveFileMigrationSheet</string>
               <string>saveStatePrecloseSheet</string>
@@ -68558,6 +68912,8 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <string>NSView</string>
               <string>NSObjectController</string>
               <string>InputManager</string>
+              <string>NSWindow</string>
+              <string>NSTextField</string>
               <string>NSObjectController</string>
               <string>NSWindow</string>
               <string>NSWindow</string>
@@ -68582,6 +68938,8 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
               <string>exportRomSavePanelAccessoryView</string>
               <string>firmwarePanelController</string>
               <string>inputManager</string>
+              <string>ndsErrorSheet</string>
+              <string>ndsErrorStatusTextField</string>
               <string>romInfoPanelController</string>
               <string>saveFileMigrationSheet</string>
               <string>saveStatePrecloseSheet</string>
@@ -68642,6 +69000,14 @@ y7bMNcy1zTXNtc42zrbPN8+40DnQutE80b7SP9LB00TTxtRJ1MvVTtXR1lXW2Ndc1+DYZNjo2WzZ8dp2
                 <string key="name">inputManager</string>
                 <string key="candidateClassName">InputManager</string>
               </object>
+              <object class="IBToOneOutletInfo">
+                <string key="name">ndsErrorSheet</string>
+                <string key="candidateClassName">NSWindow</string>
+              </object>
+              <object class="IBToOneOutletInfo">
+                <string key="name">ndsErrorStatusTextField</string>
+                <string key="candidateClassName">NSTextField</string>
+              </object>
               <object class="IBToOneOutletInfo">
                 <string key="name">romInfoPanelController</string>
                 <string key="candidateClassName">NSObjectController</string>

desmume/src/frontend/cocoa/userinterface/EmuControllerDelegate.h

@@ -61,6 +61,8 @@ class AudioSampleBlockGenerator;
 	NSWindow *slot1ManagerWindow;
 	NSWindow *saveFileMigrationSheet;
 	NSWindow *saveStatePrecloseSheet;
+	NSWindow *ndsErrorSheet;
+	NSTextField *ndsErrorStatusTextField;
 	NSView *exportRomSavePanelAccessoryView;
 	
 	BOOL isSaveStateEdited;
@@ -74,6 +76,7 @@ class AudioSampleBlockGenerator;
 	BOOL isShowingSaveStateDialog;
 	BOOL isShowingFileMigrationDialog;
 	BOOL isUserInterfaceBlockingExecution;
+	BOOL _isNDSErrorSheetAlreadyShown;
 	NSURL *currentSaveStateURL;
 	NSInteger selectedExportRomSaveID;
 	NSInteger selectedRomSaveTypeID;
@@ -130,6 +133,8 @@ class AudioSampleBlockGenerator;
 @property (readonly) IBOutlet NSWindow *slot1ManagerWindow;
 @property (readonly) IBOutlet NSWindow *saveFileMigrationSheet;
 @property (readonly) IBOutlet NSWindow *saveStatePrecloseSheet;
+@property (readonly) IBOutlet NSWindow *ndsErrorSheet;
+@property (readonly) IBOutlet NSTextField *ndsErrorStatusTextField;
 @property (readonly) IBOutlet NSView *exportRomSavePanelAccessoryView;
 
 @property (readonly) NSImage *iconExecute;
@@ -213,6 +218,7 @@ class AudioSampleBlockGenerator;
 // Misc IBActions
 - (IBAction) chooseSlot1R4Directory:(id)sender;
 - (IBAction) slot1Eject:(id)sender;
+- (IBAction) simulateEmulationCrash:(id)sender;
 
 - (IBAction) writeDefaults3DRenderingSettings:(id)sender;
 - (IBAction) writeDefaultsEmulationSettings:(id)sender;

desmume/src/frontend/cocoa/userinterface/EmuControllerDelegate.mm

@@ -59,6 +59,8 @@
 @synthesize slot1ManagerWindow;
 @synthesize saveFileMigrationSheet;
 @synthesize saveStatePrecloseSheet;
+@synthesize ndsErrorSheet;
+@synthesize ndsErrorStatusTextField;
 @synthesize exportRomSavePanelAccessoryView;
 
 @synthesize iconExecute;
@@ -116,6 +118,7 @@
 	isShowingSaveStateDialog = NO;
 	isShowingFileMigrationDialog = NO;
 	isUserInterfaceBlockingExecution = NO;
+	_isNDSErrorSheetAlreadyShown = NO;
 	
 	currentSaveStateURL = nil;
 	selectedRomSaveTypeID = ROMSAVETYPE_AUTOMATIC;
@@ -155,6 +158,11 @@
 												 name:@"org.desmume.DeSmuME.loadRomDidFinish"
 											   object:nil];
 	
+	[[NSNotificationCenter defaultCenter] addObserver:self
+											 selector:@selector(handleNDSError:)
+												 name:@"org.desmume.DeSmuME.handleNDSError"
+											   object:nil];
+	
 	return self;
 }
 
@@ -900,6 +908,12 @@
 	[cdsCore slot1Eject];
 }
 
+- (IBAction) simulateEmulationCrash:(id)sender
+{
+	CocoaDSCore *cdsCore = (CocoaDSCore *)[cdsCoreController content];
+	[cdsCore setMasterExecute:NO];
+}
+
 - (IBAction) writeDefaults3DRenderingSettings:(id)sender
 {
 	CocoaDSCore *cdsCore = (CocoaDSCore *)[cdsCoreController content];
@@ -1814,6 +1828,9 @@
 		[[windowController window] displayIfNeeded];
 	}
 	
+	[cdsCore execControl]->ApplySettingsOnReset();
+	[cdsCore setMasterExecute:YES];
+	
 	// After the ROM loading is complete, send an execute message to the Cocoa DS per
 	// user preferences.
 	if ([[NSUserDefaults standardUserDefaults] boolForKey:@"General_ExecuteROMOnLoad"])
@@ -1901,6 +1918,50 @@
 	return result;
 }
 
+- (void) handleNDSError:(NSNotification *)aNotification
+{
+	[self setIsUserInterfaceBlockingExecution:YES];
+	
+	CocoaDSCore *cdsCore = (CocoaDSCore *)[cdsCoreController content];
+	NSString *ndsErrorString = [cdsCore errorStatus];
+	const char *ndsErrorCString = [ndsErrorString cStringUsingEncoding:NSUTF8StringEncoding];
+	size_t lineCount = 1;
+	
+	for (size_t i = 0; i < [ndsErrorString length]; i++)
+	{
+		if (ndsErrorCString[i] == '\n')
+		{
+			lineCount++;
+		}
+	}
+	
+	NSRect newSheetFrameRect = [ndsErrorSheet frame];
+	newSheetFrameRect.size.height = 98.0f + (16.0f * lineCount);
+	
+	// For some reason, when the sheet is shown for the very first time,
+	// the sheet doesn't drop down as low as it should. However, upon
+	// subsequent showings, the sheet drops down to the intended distance.
+	// To compensate for this difference, the first sheet showing will
+	// have a little added height to it.
+	if (!_isNDSErrorSheetAlreadyShown)
+	{
+		_isNDSErrorSheetAlreadyShown = YES;
+		newSheetFrameRect.size.height += 22.0f;
+	}
+	
+	[ndsErrorSheet setFrame:newSheetFrameRect display:NO];
+	
+	NSRect newTextFieldRect = [ndsErrorStatusTextField frame];
+	newTextFieldRect.size.height = 16.0f * lineCount;
+	[ndsErrorStatusTextField setFrame:newTextFieldRect];
+	
+	[NSApp beginSheet:ndsErrorSheet
+	   modalForWindow:(NSWindow *)[[windowList objectAtIndex:0] window]
+		modalDelegate:self
+	   didEndSelector:@selector(didEndErrorSheet:returnCode:contextInfo:)
+		  contextInfo:nil];
+}
+
 - (void) addOutputToCore:(CocoaDSOutput *)theOutput
 {
 	CocoaDSCore *cdsCore = (CocoaDSCore *)[cdsCoreController content];
@@ -2097,6 +2158,23 @@
 	[cdsCore setSlot1R4URL:selectedDirURL];
 }
 
+- (void) didEndErrorSheet:(NSWindow *)sheet returnCode:(NSInteger)returnCode contextInfo:(void *)contextInfo
+{
+	[sheet orderOut:self];
+	[self setIsUserInterfaceBlockingExecution:NO];
+	
+	switch (returnCode)
+	{
+		case COCOA_DIALOG_OPTION: // Reset
+			[self reset:self];
+			break;
+			
+		case NSCancelButton: // Stop
+		default:
+			break;
+	}
+}
+
 - (void) updateAllWindowTitles
 {
 	if ([windowList count] < 1)

desmume/src/frontend/posix/gtk/main.cpp

@@ -2599,7 +2599,7 @@ public:
 
 static void DoQuit()
 {
-    emu_halt();
+    emu_halt(EMUHALT_REASON_USER_REQUESTED_HALT, NDSErrorTag_None);
     gtk_main_quit();
 }
 

desmume/src/frontend/windows/main.cpp

@@ -2326,7 +2326,7 @@ static void StepRunLoop_Throttle(bool allowSleep = true, int forceFrameSkip = -1
 	if (frameAdvance && allowSleep)
 	{
 		frameAdvance = false;
-		emu_halt();
+		emu_halt(EMUHALT_REASON_USER_REQUESTED_HALT, NDSErrorTag_None);
 		SPU_Pause(1);
 	}
 	if(execute && emu_paused && !frameAdvance)
@@ -2386,7 +2386,7 @@ bool NDS_Pause(bool showMsg)
 {
 	if(paused) return false;
 
-	emu_halt();
+	emu_halt(EMUHALT_REASON_USER_REQUESTED_HALT, NDSErrorTag_None);
 	paused = TRUE;
 	SPU_Pause(1);
 	while (!paused) {}
@@ -2620,7 +2620,7 @@ void MenuDeinit()
 static void ExitRunLoop()
 {
 	finished = TRUE;
-	emu_halt();
+	emu_halt(EMUHALT_REASON_USER_REQUESTED_HALT, NDSErrorTag_None);
 }
 
 class WinWifiHandler : public WifiHandler