diff --git a/src/Cafe/HW/Latte/Core/LatteThread.cpp b/src/Cafe/HW/Latte/Core/LatteThread.cpp
index a23bd5be..8874ecf4 100644
--- a/src/Cafe/HW/Latte/Core/LatteThread.cpp
+++ b/src/Cafe/HW/Latte/Core/LatteThread.cpp
@@ -187,7 +187,7 @@ int Latte_ThreadEntry()
 				rule.overwrite_settings.width >= 0 || rule.overwrite_settings.height >= 0 || rule.overwrite_settings.depth >= 0)
 			{
 				LatteGPUState.allowFramebufferSizeOptimization = false;
-				cemuLog_log(LogType::Force, "Graphic pack {} prevents rendertarget size optimization.", pack->GetName());
+				cemuLog_log(LogType::Force, "Graphic pack \"{}\" prevents rendertarget size optimization. This warning can be ignored and is intended for graphic pack developers", pack->GetName());
 				break;
 			}
 		}
diff --git a/src/Cafe/OS/libs/coreinit/coreinit.cpp b/src/Cafe/OS/libs/coreinit/coreinit.cpp
index e18d0e8d..49d232f8 100644
--- a/src/Cafe/OS/libs/coreinit/coreinit.cpp
+++ b/src/Cafe/OS/libs/coreinit/coreinit.cpp
@@ -35,12 +35,12 @@
 #include "Cafe/OS/libs/coreinit/coreinit_MEM_BlockHeap.h"
 #include "Cafe/OS/libs/coreinit/coreinit_MEM_ExpHeap.h"
 
-CoreinitSharedData* gCoreinitData = NULL;
+CoreinitSharedData* gCoreinitData = nullptr;
 
 sint32 ScoreStackTrace(OSThread_t* thread, MPTR sp)
 {
-	uint32 stackMinAddr = _swapEndianU32(thread->stackEnd);
-	uint32 stackMaxAddr = _swapEndianU32(thread->stackBase);
+	uint32 stackMinAddr = thread->stackEnd.GetMPTR();
+	uint32 stackMaxAddr = thread->stackBase.GetMPTR();
 
 	sint32 score = 0;
 	uint32 currentStackPtr = sp;
@@ -95,8 +95,8 @@ void DebugLogStackTrace(OSThread_t* thread, MPTR sp)
 
 	// print stack trace
 	uint32 currentStackPtr = highestScoreSP;
-	uint32 stackMinAddr = _swapEndianU32(thread->stackEnd);
-	uint32 stackMaxAddr = _swapEndianU32(thread->stackBase);
+	uint32 stackMinAddr = thread->stackEnd.GetMPTR();
+	uint32 stackMaxAddr = thread->stackBase.GetMPTR();
 	for (sint32 i = 0; i < 20; i++)
 	{
 		uint32 nextStackPtr = memory_readU32(currentStackPtr);
diff --git a/src/Cafe/OS/libs/coreinit/coreinit_GHS.cpp b/src/Cafe/OS/libs/coreinit/coreinit_GHS.cpp
index 5699e3e7..e2864fb9 100644
--- a/src/Cafe/OS/libs/coreinit/coreinit_GHS.cpp
+++ b/src/Cafe/OS/libs/coreinit/coreinit_GHS.cpp
@@ -22,7 +22,7 @@ namespace coreinit
 		MPTR _iob_lock[GHS_FOPEN_MAX];
 		uint16be __gh_FOPEN_MAX;
 		MEMPTR<void> ghs_environ;
-		uint32 ghs_Errno; // exposed by __gh_errno_ptr() or via 'errno' data export
+		uint32 ghs_Errno; // exposed as 'errno' data export
 	};
 
 	SysAllocator<GHSAccessibleData> g_ghs_data;
@@ -159,7 +159,7 @@ namespace coreinit
 	void* __gh_errno_ptr()
 	{
 		OSThread_t* currentThread = coreinit::OSGetCurrentThread();
-		return &currentThread->context.error;
+		return &currentThread->context.ghs_errno;
 	}
 
 	void* __get_eh_store_globals()
diff --git a/src/Cafe/OS/libs/coreinit/coreinit_IPC.cpp b/src/Cafe/OS/libs/coreinit/coreinit_IPC.cpp
index be3cb300..12d83afc 100644
--- a/src/Cafe/OS/libs/coreinit/coreinit_IPC.cpp
+++ b/src/Cafe/OS/libs/coreinit/coreinit_IPC.cpp
@@ -204,7 +204,7 @@ namespace coreinit
 		// and a message queue large enough to hold the maximum number of commands (IPC_NUM_RESOURCE_BUFFERS)
 		OSInitMessageQueue(gIPCThreadMsgQueue.GetPtr() + coreIndex, _gIPCThreadSemaphoreStorage.GetPtr() + coreIndex * IPC_NUM_RESOURCE_BUFFERS, IPC_NUM_RESOURCE_BUFFERS);
 		OSThread_t* ipcThread = gIPCThread.GetPtr() + coreIndex;
-		OSCreateThreadType(ipcThread, PPCInterpreter_makeCallableExportDepr(__IPCDriverThreadFunc), 0, nullptr, _gIPCThreadStack.GetPtr() + 0x4000 * coreIndex + 0x4000, 0x4000, 15, (1 << coreIndex), OSThread_t::THREAD_TYPE::TYPE_DRIVER);
+		__OSCreateThreadType(ipcThread, PPCInterpreter_makeCallableExportDepr(__IPCDriverThreadFunc), 0, nullptr, _gIPCThreadStack.GetPtr() + 0x4000 * coreIndex + 0x4000, 0x4000, 15, (1 << coreIndex), OSThread_t::THREAD_TYPE::TYPE_DRIVER);
 		sprintf((char*)_gIPCThreadNameStorage.GetPtr()+coreIndex*0x18, "{SYS IPC Core %d}", coreIndex);
 		OSSetThreadName(ipcThread, (char*)_gIPCThreadNameStorage.GetPtr() + coreIndex * 0x18);
 		OSResumeThread(ipcThread);
diff --git a/src/Cafe/OS/libs/coreinit/coreinit_Thread.cpp b/src/Cafe/OS/libs/coreinit/coreinit_Thread.cpp
index 654e57a8..533360aa 100644
--- a/src/Cafe/OS/libs/coreinit/coreinit_Thread.cpp
+++ b/src/Cafe/OS/libs/coreinit/coreinit_Thread.cpp
@@ -215,14 +215,171 @@ namespace coreinit
 		hCPU->spr.LR = lr;
 		hCPU->gpr[3] = r3;
 		hCPU->gpr[4] = r4;
-		hCPU->instructionPointer = _swapEndianU32(currentThread->entrypoint);
+		hCPU->instructionPointer = currentThread->entrypoint.GetMPTR();
 	}
 
 	void coreinitExport_OSExitThreadDepr(PPCInterpreter_t* hCPU);
 
-	void OSCreateThreadInternal(OSThread_t* thread, uint32 entryPoint, MPTR stackLowerBaseAddr, uint32 stackSize, uint8 affinityMask, OSThread_t::THREAD_TYPE threadType)
+	void __OSInitContext(OSContext_t* ctx, MEMPTR<void> initialIP, MEMPTR<void> initialStackPointer)
+	{
+		ctx->SetContextMagic();
+		ctx->gpr[0] = 0; // r0 is left uninitialized on console?
+		for(auto& it : ctx->gpr)
+			it = 0;
+		ctx->gpr[1] = _swapEndianU32(initialStackPointer.GetMPTR());
+		ctx->gpr[2] = _swapEndianU32(RPLLoader_GetSDA2Base());
+		ctx->gpr[13] = _swapEndianU32(RPLLoader_GetSDA1Base());
+		ctx->srr0 = initialIP.GetMPTR();
+		ctx->cr = 0;
+		ctx->ukn0A8 = 0;
+		ctx->ukn0AC = 0;
+		ctx->gqr[0] = 0;
+		ctx->gqr[1] = 0;
+		ctx->gqr[2] = 0;
+		ctx->gqr[3] = 0;
+		ctx->gqr[4] = 0;
+		ctx->gqr[5] = 0;
+		ctx->gqr[6] = 0;
+		ctx->gqr[7] = 0;
+		ctx->dsi_dar = 0;
+		ctx->srr1 = 0x9032;
+		ctx->xer = 0;
+		ctx->dsi_dsisr = 0;
+		ctx->upir = 0;
+		ctx->boostCount = 0;
+		ctx->state = 0;
+		for(auto& it : ctx->coretime)
+			it = 0;
+		ctx->starttime = 0;
+		ctx->ghs_errno = 0;
+		ctx->upmc1 = 0;
+		ctx->upmc2 = 0;
+		ctx->upmc3 = 0;
+		ctx->upmc4 = 0;
+		ctx->ummcr0 = 0;
+		ctx->ummcr1 = 0;
+	}
+
+	void __OSThreadInit(OSThread_t* thread, MEMPTR<void> entrypoint, uint32 argInt, MEMPTR<void> argPtr, MEMPTR<void> stackTop, uint32 stackSize, sint32 priority, uint32 upirCoreIndex, OSThread_t::THREAD_TYPE threadType)
+	{
+		thread->effectivePriority = priority;
+		thread->type = threadType;
+		thread->basePriority = priority;
+		thread->SetThreadMagic();
+		thread->id = 0x8000;
+		thread->waitAlarm = nullptr;
+		thread->entrypoint = entrypoint;
+		thread->quantumTicks = 0;
+		if(entrypoint)
+		{
+			thread->state = OSThread_t::THREAD_STATE::STATE_READY;
+			thread->suspendCounter = 1;
+		}
+		else
+		{
+			thread->state = OSThread_t::THREAD_STATE::STATE_NONE;
+			thread->suspendCounter = 0;
+		}
+		thread->exitValue = (uint32)-1;
+		thread->requestFlags = OSThread_t::REQUEST_FLAG_BIT::REQUEST_FLAG_NONE;
+		thread->pendingSuspend = 0;
+		thread->suspendResult = 0xFFFFFFFF;
+		thread->coretimeSumQuantumStart = 0;
+		thread->deallocatorFunc = nullptr;
+		thread->cleanupCallback = nullptr;
+		thread->waitingForFastMutex = nullptr;
+		thread->stateFlags = 0;
+		thread->waitingForMutex = nullptr;
+		memset(&thread->crt, 0, sizeof(thread->crt));
+		static_assert(sizeof(thread->crt) == 0x1D8);
+		thread->tlsBlocksMPTR = 0;
+		thread->numAllocatedTLSBlocks = 0;
+		thread->tlsStatus = 0;
+		OSInitThreadQueueEx(&thread->joinQueue, thread);
+		OSInitThreadQueueEx(&thread->suspendQueue, thread);
+		thread->mutexQueue.ukn08 = thread;
+		thread->mutexQueue.ukn0C = 0;
+		thread->mutexQueue.tail = nullptr;
+		thread->mutexQueue.head = nullptr;
+		thread->ownedFastMutex.next = nullptr;
+		thread->ownedFastMutex.prev = nullptr;
+		thread->contendedFastMutex.next = nullptr;
+		thread->contendedFastMutex.prev = nullptr;
+
+		MEMPTR<void> alignedStackTop{MEMPTR<void>(stackTop).GetMPTR() & 0xFFFFFFF8};
+		MEMPTR<uint32be> alignedStackTop32{alignedStackTop};
+		alignedStackTop32[-1] = 0;
+		alignedStackTop32[-2] = 0;
+
+		__OSInitContext(&thread->context, MEMPTR<void>(PPCInterpreter_makeCallableExportDepr(threadEntry)), (void*)(alignedStackTop32.GetPtr() - 2));
+		thread->stackBase = stackTop; // without alignment
+		thread->stackEnd = ((uint8*)stackTop.GetPtr() - stackSize);
+		thread->context.upir = upirCoreIndex;
+		thread->context.lr = _swapEndianU32(PPCInterpreter_makeCallableExportDepr(coreinitExport_OSExitThreadDepr));
+		thread->context.gpr[3] = _swapEndianU32(argInt);
+		thread->context.gpr[4] = _swapEndianU32(argPtr.GetMPTR());
+
+		*(uint32be*)((uint8*)stackTop.GetPtr() - stackSize) = 0xDEADBABE;
+		thread->alarmRelatedUkn = 0;
+		for(auto& it : thread->specificArray)
+			it = nullptr;
+		thread->context.fpscr.fpscr = 4;
+		for(sint32 i=0; i<32; i++)
+		{
+			thread->context.fp_ps0[i] = 0.0;
+			thread->context.fp_ps1[i] = 0.0;
+		}
+		thread->context.gqr[2] = 0x40004;
+		thread->context.gqr[3] = 0x50005;
+		thread->context.gqr[4] = 0x60006;
+		thread->context.gqr[5] = 0x70007;
+
+		for(sint32 i=0; i<Espresso::CORE_COUNT; i++)
+			thread->context.coretime[i] = 0;
+
+		// currentRunQueue and waitQueueLink is not initialized by COS and instead overwritten without validation
+		// since we already have integrity checks in other functions, lets initialize it here
+		for(sint32 i=0; i<Espresso::CORE_COUNT; i++)
+			thread->currentRunQueue[i] = nullptr;
+		thread->waitQueueLink.prev = nullptr;
+		thread->waitQueueLink.next = nullptr;
+
+		thread->wakeTimeRelatedUkn2 = 0;
+		thread->wakeUpCount = 0;
+		thread->wakeUpTime = 0;
+		thread->wakeTimeRelatedUkn1 = 0x7FFFFFFFFFFFFFFF;
+		thread->quantumTicks = 0;
+		thread->coretimeSumQuantumStart = 0;
+		thread->totalCycles = 0;
+
+		for(auto& it : thread->padding68C)
+			it = 0;
+	}
+
+	void SetThreadAffinityToCore(OSThread_t* thread, uint32 coreIndex)
+	{
+		cemu_assert_debug(coreIndex < 3);
+		thread->attr &= ~(OSThread_t::ATTR_BIT::ATTR_AFFINITY_CORE0 | OSThread_t::ATTR_BIT::ATTR_AFFINITY_CORE1 | OSThread_t::ATTR_BIT::ATTR_AFFINITY_CORE2 | OSThread_t::ATTR_BIT::ATTR_UKN_010);
+		thread->context.affinity &= 0xFFFFFFF8;
+		if (coreIndex == 0)
+		{
+			thread->attr |= OSThread_t::ATTR_BIT::ATTR_AFFINITY_CORE0;
+			thread->context.affinity |= (1<<0);
+		}
+		else if (coreIndex == 1)
+		{
+			thread->attr |= OSThread_t::ATTR_BIT::ATTR_AFFINITY_CORE1;
+			thread->context.affinity |= (1<<1);
+		}
+		else // if (coreIndex == 2)
+		{
+			thread->attr |= OSThread_t::ATTR_BIT::ATTR_AFFINITY_CORE2;
+			thread->context.affinity |= (1<<2);
+		}
+	}
+
+	void __OSCreateThreadOnActiveThreadWorkaround(OSThread_t* thread)
 	{
-		cemu_assert_debug(thread != nullptr); // make thread struct mandatory. Caller can always use SysAllocator
 		__OSLockScheduler();
 		bool isThreadStillActive = __OSIsThreadActive(thread);
 		if (isThreadStillActive)
@@ -248,84 +405,97 @@ namespace coreinit
 		}
 		cemu_assert_debug(__OSIsThreadActive(thread) == false);
 		__OSUnlockScheduler();
-		memset(thread, 0x00, sizeof(OSThread_t));
-		// init signatures
-		thread->SetMagic();
-		thread->type = threadType;
-		thread->state = (entryPoint != MPTR_NULL) ? OSThread_t::THREAD_STATE::STATE_READY : OSThread_t::THREAD_STATE::STATE_NONE;
-		thread->entrypoint = _swapEndianU32(entryPoint);
-		__OSSetThreadBasePriority(thread, 0);
-		__OSUpdateThreadEffectivePriority(thread);
-		// untested, but seems to work (Batman Arkham City uses these values to calculate the stack size for duplicated threads)
-		thread->stackBase = _swapEndianU32(stackLowerBaseAddr + stackSize); // these fields are quite important and lots of games rely on them being accurate (Examples: Darksiders 2, SMW3D, Batman Arkham City)
-		thread->stackEnd = _swapEndianU32(stackLowerBaseAddr);
-		// init stackpointer
-		thread->context.gpr[GPR_SP] = _swapEndianU32(stackLowerBaseAddr + stackSize - 0x20); // how many free bytes should there be at the beginning of the stack?
-		// init misc stuff
-		thread->attr = affinityMask;
-		thread->context.setAffinity(affinityMask);
-		thread->context.srr0 = PPCInterpreter_makeCallableExportDepr(threadEntry);
-		thread->context.lr = _swapEndianU32(PPCInterpreter_makeCallableExportDepr(coreinitExport_OSExitThreadDepr));
-		thread->id = 0x8000; // Warriors Orochi 3 softlocks if this is zero due to confusing threads (_OSActivateThread should set this?)
-		// init ugqr
-		thread->context.gqr[0] = 0x00000000;
-		thread->context.gqr[1] = 0x00000000;
-		thread->context.gqr[2] = 0x00040004;
-		thread->context.gqr[3] = 0x00050005;
-		thread->context.gqr[4] = 0x00060006;
-		thread->context.gqr[5] = 0x00070007;
-		thread->context.gqr[6] = 0x00000000;
-		thread->context.gqr[7] = 0x00000000;
-		// init r2 (SDA2) and r3 (SDA)
-		thread->context.gpr[2] = _swapEndianU32(RPLLoader_GetSDA2Base());
-		thread->context.gpr[13] = _swapEndianU32(RPLLoader_GetSDA1Base());
-		// GHS related thread init?
+	}
 
-		__OSLockScheduler();
-		// if entrypoint is non-zero then put the thread on the active list and suspend it
-		if (entryPoint != MPTR_NULL)
+	bool __OSCreateThreadInternal2(OSThread_t* thread, MEMPTR<void> entrypoint, uint32 argInt, MEMPTR<void> argPtr, MEMPTR<void> stackBase, uint32 stackSize, sint32 priority, uint32 attrBits, OSThread_t::THREAD_TYPE threadType)
+	{
+		__OSCreateThreadOnActiveThreadWorkaround(thread);
+		OSThread_t* currentThread = OSGetCurrentThread();
+		if (priority < 0 || priority >= 32)
 		{
-			thread->suspendCounter = 1;
-			__OSActivateThread(thread);
-			thread->state = OSThread_t::THREAD_STATE::STATE_READY;
+			cemuLog_log(LogType::APIErrors, "OSCreateThreadInternal: Thread priority must be in range 0-31");
+			return false;
+		}
+		if (threadType == OSThread_t::THREAD_TYPE::TYPE_IO)
+		{
+			priority = priority + 0x20;
+		}
+		else if (threadType == OSThread_t::THREAD_TYPE::TYPE_APP)
+		{
+			priority = priority + 0x40;
+		}
+		if(attrBits >= 0x20 || stackBase == nullptr || stackSize == 0)
+		{
+			cemuLog_logDebug(LogType::APIErrors, "OSCreateThreadInternal: Invalid attributes, stack base or size");
+			return false;
+		}
+		uint32 im = OSDisableInterrupts();
+		__OSLockScheduler(thread);
+
+		uint32 coreIndex = PPCInterpreter_getCurrentInstance() ? OSGetCoreId() : 1;
+		__OSThreadInit(thread, entrypoint, argInt, argPtr, stackBase, stackSize, priority, coreIndex, threadType);
+		thread->threadName = nullptr;
+		thread->context.affinity = attrBits & 7;
+		thread->attr = attrBits;
+		if ((attrBits & 7) == 0) // if no explicit affinity is given, use the current core
+			SetThreadAffinityToCore(thread, OSGetCoreId());
+		if(currentThread)
+		{
+			for(sint32 i=0; i<Espresso::CORE_COUNT; i++)
+			{
+				thread->dsiCallback[i] = currentThread->dsiCallback[i];
+				thread->isiCallback[i] = currentThread->isiCallback[i];
+				thread->programCallback[i] = currentThread->programCallback[i];
+				thread->perfMonCallback[i] = currentThread->perfMonCallback[i];
+				thread->alignmentExceptionCallback[i] = currentThread->alignmentExceptionCallback[i];
+			}
+			thread->context.srr1 = thread->context.srr1 | (currentThread->context.srr1 & 0x900);
+			thread->context.fpscr.fpscr = thread->context.fpscr.fpscr | (currentThread->context.fpscr.fpscr & 0xF8);
 		}
 		else
-			thread->suspendCounter = 0;
-		__OSUnlockScheduler();
+		{
+			for(sint32 i=0; i<Espresso::CORE_COUNT; i++)
+			{
+				thread->dsiCallback[i] = 0;
+				thread->isiCallback[i] = 0;
+				thread->programCallback[i] = 0;
+				thread->perfMonCallback[i] = 0;
+				thread->alignmentExceptionCallback[i] = nullptr;
+			}
+		}
+		if (entrypoint)
+		{
+			thread->id = 0x8000;
+			__OSActivateThread(thread); // also handles adding the thread to g_activeThreadQueue
+		}
+		__OSUnlockScheduler(thread);
+		OSRestoreInterrupts(im);
+		// recompile entry point function
+		if (entrypoint)
+			PPCRecompiler_recompileIfUnvisited(entrypoint.GetMPTR());
+		return true;
 	}
 
 	bool OSCreateThreadType(OSThread_t* thread, MPTR entryPoint, sint32 numParam, void* ptrParam, void* stackTop, sint32 stackSize, sint32 priority, uint32 attr, OSThread_t::THREAD_TYPE threadType)
 	{
-		OSCreateThreadInternal(thread, entryPoint, memory_getVirtualOffsetFromPointer(stackTop) - stackSize, stackSize, attr, threadType);
-		thread->context.gpr[3] = _swapEndianU32(numParam); // num arguments
-		thread->context.gpr[4] = _swapEndianU32(memory_getVirtualOffsetFromPointer(ptrParam)); // arguments pointer
-		__OSSetThreadBasePriority(thread, priority);
-		__OSUpdateThreadEffectivePriority(thread);
-		// set affinity
-		uint8 affinityMask = 0;
-		affinityMask = attr & 0x7;
-		// if no core is selected -> set current one
-		if (affinityMask == 0)
-			affinityMask |= (1 << PPCInterpreter_getCoreIndex(PPCInterpreter_getCurrentInstance()));
-		// set attr
-		// todo: Support for other attr bits
-		thread->attr = (affinityMask & 0xFF) | (attr & OSThread_t::ATTR_BIT::ATTR_DETACHED);
-		thread->context.setAffinity(affinityMask);
-		// recompile entry point function
-		if (entryPoint != MPTR_NULL)
-			PPCRecompiler_recompileIfUnvisited(entryPoint);
-		return true;
+		if(threadType != OSThread_t::THREAD_TYPE::TYPE_APP && threadType != OSThread_t::THREAD_TYPE::TYPE_IO)
+		{
+			cemuLog_logDebug(LogType::APIErrors, "OSCreateThreadType: Invalid thread type");
+			cemu_assert_suspicious();
+			return false;
+		}
+		return __OSCreateThreadInternal2(thread, MEMPTR<void>(entryPoint), numParam, ptrParam, stackTop, stackSize, priority, attr, threadType);
 	}
 
 	bool OSCreateThread(OSThread_t* thread, MPTR entryPoint, sint32 numParam, void* ptrParam, void* stackTop, sint32 stackSize, sint32 priority, uint32 attr)
 	{
-		return OSCreateThreadType(thread, entryPoint, numParam, ptrParam, stackTop, stackSize, priority, attr, OSThread_t::THREAD_TYPE::TYPE_APP);
+		return __OSCreateThreadInternal2(thread, MEMPTR<void>(entryPoint), numParam, ptrParam, stackTop, stackSize, priority, attr, OSThread_t::THREAD_TYPE::TYPE_APP);
 	}
 
-	// alias to OSCreateThreadType, similar to OSCreateThread, but with an additional parameter for the thread type
+	// similar to OSCreateThreadType, but can be used to create any type of thread
 	bool __OSCreateThreadType(OSThread_t* thread, MPTR entryPoint, sint32 numParam, void* ptrParam, void* stackTop, sint32 stackSize, sint32 priority, uint32 attr, OSThread_t::THREAD_TYPE threadType)
 	{
-		return OSCreateThreadType(thread, entryPoint, numParam, ptrParam, stackTop, stackSize, priority, attr, threadType);
+		return __OSCreateThreadInternal2(thread, MEMPTR<void>(entryPoint), numParam, ptrParam, stackTop, stackSize, priority, attr, threadType);
 	}
 
 	bool OSRunThread(OSThread_t* thread, MPTR funcAddress, sint32 numParam, void* ptrParam)
@@ -352,7 +522,7 @@ namespace coreinit
 		// set thread state
 		// todo - this should fully reinitialize the thread?
 
-		thread->entrypoint = _swapEndianU32(funcAddress);
+		thread->entrypoint = funcAddress;
 		thread->context.srr0 = PPCInterpreter_makeCallableExportDepr(threadEntry);
 		thread->context.lr = _swapEndianU32(PPCInterpreter_makeCallableExportDepr(coreinitExport_OSExitThreadDepr));
 		thread->context.gpr[3] = _swapEndianU32(numParam);
@@ -378,10 +548,10 @@ namespace coreinit
 		OSThread_t* currentThread = coreinit::OSGetCurrentThread();
 
 		// thread cleanup callback
-		if (!currentThread->cleanupCallback2.IsNull())
+		if (currentThread->cleanupCallback)
 		{
 			currentThread->stateFlags = _swapEndianU32(_swapEndianU32(currentThread->stateFlags) | 0x00000001);
-			PPCCoreCallback(currentThread->cleanupCallback2.GetMPTR(), currentThread, _swapEndianU32(currentThread->stackEnd));
+			PPCCoreCallback(currentThread->cleanupCallback.GetMPTR(), currentThread, currentThread->stackEnd);
 		}
 		// cpp exception cleanup
 		if (gCoreinitData->__cpp_exception_cleanup_ptr != 0 && currentThread->crt.eh_globals != nullptr)
@@ -602,7 +772,10 @@ namespace coreinit
 		sint32 previousSuspendCount = thread->suspendCounter;
 		cemu_assert_debug(previousSuspendCount >= 0);
 		if (previousSuspendCount == 0)
+		{
+			cemuLog_log(LogType::APIErrors, "OSResumeThread: Resuming thread 0x{:08x} which isn't suspended", MEMPTR<OSThread_t>(thread).GetMPTR());
 			return 0;
+		}
 		thread->suspendCounter = previousSuspendCount - resumeCount;
 		if (thread->suspendCounter < 0)
 			thread->suspendCounter = 0;
@@ -732,8 +905,8 @@ namespace coreinit
 	void* OSSetThreadCleanupCallback(OSThread_t* thread, void* cleanupCallback)
 	{
 		__OSLockScheduler();
-		void* previousFunc = thread->cleanupCallback2.GetPtr();
-		thread->cleanupCallback2 = cleanupCallback;
+		void* previousFunc = thread->cleanupCallback.GetPtr();
+		thread->cleanupCallback = cleanupCallback;
 		__OSUnlockScheduler();
 		return previousFunc;
 	}
@@ -1341,7 +1514,7 @@ namespace coreinit
 	void __OSQueueThreadDeallocation(OSThread_t* thread)
 	{
 		uint32 coreIndex = OSGetCoreId();
-		TerminatorThread::DeallocatorQueueEntry queueEntry(thread, memory_getPointerFromVirtualOffset(_swapEndianU32(thread->stackEnd)), thread->deallocatorFunc);
+		TerminatorThread::DeallocatorQueueEntry queueEntry(thread, thread->stackEnd, thread->deallocatorFunc);
 		s_terminatorThreads[coreIndex].queueDeallocators.push(queueEntry);
 		OSSignalSemaphoreInternal(s_terminatorThreads[coreIndex].semaphoreQueuedDeallocators.GetPtr(), false); // do not reschedule here! Current thread must not be interrupted otherwise deallocator will run too early
 	}
diff --git a/src/Cafe/OS/libs/coreinit/coreinit_Thread.h b/src/Cafe/OS/libs/coreinit/coreinit_Thread.h
index b401d96d..fdbcfea7 100644
--- a/src/Cafe/OS/libs/coreinit/coreinit_Thread.h
+++ b/src/Cafe/OS/libs/coreinit/coreinit_Thread.h
@@ -2,9 +2,6 @@
 #include "Cafe/HW/Espresso/Const.h"
 #include "Cafe/OS/libs/coreinit/coreinit_Scheduler.h"
 
-#define OS_CONTEXT_MAGIC_0					'OSCo'
-#define OS_CONTEXT_MAGIC_1					'ntxt'
-
 struct OSThread_t;
 
 struct OSContextRegFPSCR_t
@@ -16,6 +13,9 @@ struct OSContextRegFPSCR_t
 
 struct OSContext_t
 {
+	static constexpr uint32 OS_CONTEXT_MAGIC_0 = 0x4f53436f; // "OSCo"
+	static constexpr uint32 OS_CONTEXT_MAGIC_1 = 0x6e747874; // "ntxt"
+
 	/* +0x000 */ betype<uint32> magic0;
 	/* +0x004 */ betype<uint32> magic1;
 	/* +0x008 */ uint32 gpr[32];
@@ -36,24 +36,29 @@ struct OSContext_t
 	/* +0x1BC */ uint32 gqr[8];			// GQR/UGQR
 	/* +0x1DC */ uint32be upir;			// set to current core index
 	/* +0x1E0 */ uint64be fp_ps1[32];
-	/* +0x2E0 */ uint64 uknTime2E0;
-	/* +0x2E8 */ uint64 uknTime2E8;
-	/* +0x2F0 */ uint64 uknTime2F0;
-	/* +0x2F8 */ uint64 uknTime2F8;
-	/* +0x300 */ uint32 error;         // returned by __gh_errno_ptr() (used by socketlasterr)
+	/* +0x2E0 */ uint64be coretime[3];
+	/* +0x2F8 */ uint64be starttime;
+	/* +0x300 */ uint32be ghs_errno;         // returned by __gh_errno_ptr() (used by socketlasterr)
 	/* +0x304 */ uint32be affinity;
-	/* +0x308 */ uint32 ukn0308;
-	/* +0x30C */ uint32 ukn030C;
-	/* +0x310 */ uint32 ukn0310;
-	/* +0x314 */ uint32 ukn0314;
-	/* +0x318 */ uint32 ukn0318;
-	/* +0x31C */ uint32 ukn031C;
+	/* +0x308 */ uint32be upmc1;
+	/* +0x30C */ uint32be upmc2;
+	/* +0x310 */ uint32be upmc3;
+	/* +0x314 */ uint32be upmc4;
+	/* +0x318 */ uint32be ummcr0;
+	/* +0x31C */ uint32be ummcr1;
 
 	bool checkMagic()
 	{
 		return magic0 == (uint32)OS_CONTEXT_MAGIC_0 && magic1 == (uint32)OS_CONTEXT_MAGIC_1;
 	}
 
+	void SetContextMagic()
+	{
+		magic0 = OS_CONTEXT_MAGIC_0;
+		magic1 = OS_CONTEXT_MAGIC_1;
+	}
+
+
 	bool hasCoreAffinitySet(uint32 coreIndex) const
 	{
 		return (((uint32)affinity >> coreIndex) & 1) != 0;
@@ -361,6 +366,8 @@ namespace coreinit
 
 struct OSThread_t
 {
+	static constexpr uint32 MAGIC_THREAD = 0x74487244; // "tHrD"
+
 	enum class THREAD_TYPE : uint32
 	{
 		TYPE_DRIVER = 0,
@@ -383,7 +390,7 @@ struct OSThread_t
 		ATTR_AFFINITY_CORE1 = 0x2,
 		ATTR_AFFINITY_CORE2 = 0x4,
 		ATTR_DETACHED		= 0x8,
-		// more flags?
+		ATTR_UKN_010		= 0x10,
 	};
 
 	enum REQUEST_FLAG_BIT : uint32
@@ -404,23 +411,21 @@ struct OSThread_t
 		return 0;
 	}
 
-    void SetMagic()
+    void SetThreadMagic()
     {
-        context.magic0 = OS_CONTEXT_MAGIC_0;
-        context.magic1 = OS_CONTEXT_MAGIC_1;
-        magic = 'tHrD';
+        magic = MAGIC_THREAD;
     }
 
     bool IsValidMagic() const
     {
-        return magic == 'tHrD' && context.magic0 == OS_CONTEXT_MAGIC_0 && context.magic1 == OS_CONTEXT_MAGIC_1;
+        return magic == MAGIC_THREAD && context.magic0 == OSContext_t::OS_CONTEXT_MAGIC_0 && context.magic1 == OSContext_t::OS_CONTEXT_MAGIC_1;
     }
 
 	/* +0x000 */ OSContext_t						context;
-	/* +0x320 */ uint32be							magic;								// 'tHrD'
+	/* +0x320 */ uint32be							magic;								// "tHrD" (0x74487244)
 	/* +0x324 */ betype<THREAD_STATE>				state;
 	/* +0x325 */ uint8								attr;
-	/* +0x326 */ uint16be							id;									// Warriors Orochi 3 uses this to identify threads. Seems like this is always set to 0x8000 ?
+	/* +0x326 */ uint16be							id;									// Warriors Orochi 3 uses this to identify threads
 	/* +0x328 */ betype<sint32>						suspendCounter;
 	/* +0x32C */ sint32be							effectivePriority;					// effective priority (lower is higher)
 	/* +0x330 */ sint32be							basePriority;						// base priority (lower is higher)
@@ -440,21 +445,21 @@ struct OSThread_t
 
 	/* +0x38C */ coreinit::OSThreadLink				activeThreadChain;					// queue of active threads (g_activeThreadQueue)
 
-	/* +0x394 */ MPTR								stackBase;							// upper limit of stack
-	/* +0x398 */ MPTR								stackEnd;							// lower limit of stack
+	/* +0x394 */ MEMPTR<void>						stackBase;							// upper limit of stack
+	/* +0x398 */ MEMPTR<void>						stackEnd;							// lower limit of stack
 
-	/* +0x39C */ MPTR								entrypoint;
+	/* +0x39C */ MEMPTR<void>						entrypoint;
 	/* +0x3A0 */ crt_t								crt;
 
 	/* +0x578 */ sint32								alarmRelatedUkn;
 	/* +0x57C */ std::array<MEMPTR<void>, 16>		specificArray;
 	/* +0x5BC */ betype<THREAD_TYPE>				type;
 	/* +0x5C0 */ MEMPTR<const char>					threadName;
-	/* +0x5C4 */ MPTR								waitAlarm;							// used only by OSWaitEventWithTimeout/OSSignalEvent ?
+	/* +0x5C4 */ MEMPTR<void>						waitAlarm;							// used only by OSWaitEventWithTimeout/OSSignalEvent ?
 
 	/* +0x5C8 */ uint32								userStackPointer;
 
-	/* +0x5CC */ MEMPTR<void>						cleanupCallback2;
+	/* +0x5CC */ MEMPTR<void>						cleanupCallback;
 	/* +0x5D0 */ MEMPTR<void>						deallocatorFunc;
 
 	/* +0x5D4 */ uint32								stateFlags;						// 0x5D4 | various flags? Controls if canceling/suspension is allowed (at cancel points) or not? If 1 -> Cancel/Suspension not allowed, if 0 -> Cancel/Suspension allowed
@@ -480,19 +485,21 @@ struct OSThread_t
 
 	/* +0x660 */ uint32								ukn660;
 
+	// todo - some of the members towards the end of the struct were only added in later COS versions. Figure out the mapping between version and members
+
 	// TLS
 	/* +0x664 */ uint16								numAllocatedTLSBlocks;
 	/* +0x666 */ sint16								tlsStatus;
 	/* +0x668 */ MPTR								tlsBlocksMPTR;
-
+	
 	/* +0x66C */ MEMPTR<coreinit::OSFastMutex>		waitingForFastMutex;
 	/* +0x670 */ coreinit::OSFastMutexLink			contendedFastMutex;
 	/* +0x678 */ coreinit::OSFastMutexLink			ownedFastMutex;
+	/* +0x680 */ MEMPTR<void>						alignmentExceptionCallback[Espresso::CORE_COUNT];
 
-	/* +0x680 */ uint32								padding680[28 / 4];
+	/* +0x68C */ uint32								padding68C[20 / 4];
 };
-
-static_assert(sizeof(OSThread_t) == 0x6A0-4); // todo - determine correct size
+static_assert(sizeof(OSThread_t) == 0x6A0);
 
 namespace coreinit
 {
diff --git a/src/Cafe/OS/libs/nsysnet/nsysnet.cpp b/src/Cafe/OS/libs/nsysnet/nsysnet.cpp
index 88bca8af..dd7c9189 100644
--- a/src/Cafe/OS/libs/nsysnet/nsysnet.cpp
+++ b/src/Cafe/OS/libs/nsysnet/nsysnet.cpp
@@ -117,10 +117,10 @@ void nsysnetExport_socket_lib_finish(PPCInterpreter_t* hCPU)
 	osLib_returnFromFunction(hCPU, 0); // 0 -> Success
 }
 
-uint32* __gh_errno_ptr()
+static uint32be* __gh_errno_ptr()
 {
 	OSThread_t* osThread = coreinit::OSGetCurrentThread();
-	return &osThread->context.error;
+	return &osThread->context.ghs_errno;
 }
 
 void _setSockError(sint32 errCode)
diff --git a/src/Cafe/OS/libs/snd_core/ax_ist.cpp b/src/Cafe/OS/libs/snd_core/ax_ist.cpp
index 30cbdbb1..17f247e0 100644
--- a/src/Cafe/OS/libs/snd_core/ax_ist.cpp
+++ b/src/Cafe/OS/libs/snd_core/ax_ist.cpp
@@ -963,7 +963,7 @@ namespace snd_core
 		OSInitMessageQueue(__AXIstThreadMsgQueue.GetPtr(), __AXIstThreadMsgArray.GetPtr(), 0x10);
 		// create thread
 		uint8 istThreadAttr = 0;
-		coreinit::OSCreateThreadType(__AXIstThread.GetPtr(), PPCInterpreter_makeCallableExportDepr(AXIst_ThreadEntry), 0, &__AXIstThreadMsgQueue, __AXIstThreadStack.GetPtr() + 0x4000, 0x4000, 14, istThreadAttr, OSThread_t::THREAD_TYPE::TYPE_DRIVER);
+		coreinit::__OSCreateThreadType(__AXIstThread.GetPtr(), PPCInterpreter_makeCallableExportDepr(AXIst_ThreadEntry), 0, &__AXIstThreadMsgQueue, __AXIstThreadStack.GetPtr() + 0x4000, 0x4000, 14, istThreadAttr, OSThread_t::THREAD_TYPE::TYPE_DRIVER);
 		coreinit::OSResumeThread(__AXIstThread.GetPtr());
 	}
 
diff --git a/src/Common/ExceptionHandler/ExceptionHandler.cpp b/src/Common/ExceptionHandler/ExceptionHandler.cpp
index 5fefc8ca..b6755fd8 100644
--- a/src/Common/ExceptionHandler/ExceptionHandler.cpp
+++ b/src/Common/ExceptionHandler/ExceptionHandler.cpp
@@ -155,7 +155,7 @@ void ExceptionHandler_LogGeneralInfo()
         const char* threadName = "NULL";
         if (!threadItrBE->threadName.IsNull())
             threadName = threadItrBE->threadName.GetPtr();
-        sprintf(dumpLine, "%08x Ent %08x IP %08x LR %08x %-9s Aff %d%d%d Pri %2d Name %s", threadItrMPTR, _swapEndianU32(threadItrBE->entrypoint), threadItrBE->context.srr0, _swapEndianU32(threadItrBE->context.lr), threadStateStr, (affinity >> 0) & 1, (affinity >> 1) & 1, (affinity >> 2) & 1, effectivePriority, threadName);
+        sprintf(dumpLine, "%08x Ent %08x IP %08x LR %08x %-9s Aff %d%d%d Pri %2d Name %s", threadItrMPTR, threadItrBE->entrypoint.GetMPTR(), threadItrBE->context.srr0, _swapEndianU32(threadItrBE->context.lr), threadStateStr, (affinity >> 0) & 1, (affinity >> 1) & 1, (affinity >> 2) & 1, effectivePriority, threadName);
         // write line to log
         CrashLog_WriteLine(dumpLine);
     }
diff --git a/src/gui/windows/PPCThreadsViewer/DebugPPCThreadsWindow.cpp b/src/gui/windows/PPCThreadsViewer/DebugPPCThreadsWindow.cpp
index bd71942f..dfbaf76e 100644
--- a/src/gui/windows/PPCThreadsViewer/DebugPPCThreadsWindow.cpp
+++ b/src/gui/windows/PPCThreadsViewer/DebugPPCThreadsWindow.cpp
@@ -195,10 +195,10 @@ void DebugPPCThreadsWindow::RefreshThreadList()
             m_thread_list->InsertItem(item);
             m_thread_list->SetItemData(item, (long)threadItrMPTR);
             // entry point
-            sprintf(tempStr, "%08X", _swapEndianU32(cafeThread->entrypoint));
+            sprintf(tempStr, "%08X", cafeThread->entrypoint.GetMPTR());
             m_thread_list->SetItem(i, 1, tempStr);
             // stack base (low)
-            sprintf(tempStr, "%08X - %08X", _swapEndianU32(cafeThread->stackEnd), _swapEndianU32(cafeThread->stackBase));
+            sprintf(tempStr, "%08X - %08X", cafeThread->stackEnd.GetMPTR(), cafeThread->stackBase.GetMPTR());
             m_thread_list->SetItem(i, 2, tempStr);
             // pc
             RPLStoredSymbol* symbol = rplSymbolStorage_getByAddress(cafeThread->context.srr0);