X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86%2Fproc.c;h=7d54d0c2ea1004121fe48b859f88d5a3bc6e53dd;hb=a20cfd571f504f5c7f2d29516442a12c200441d5;hp=94de734f5e8bf4fb38ae2406bfd1e36b8d90e834;hpb=31ca5892d8cdc523fbd22d95b9accb0e76c4f234;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86/proc.c b/Kernel/arch/x86/proc.c
index 94de734f..7d54d0c2 100644
--- a/Kernel/arch/x86/proc.c
+++ b/Kernel/arch/x86/proc.c
@@ -11,63 +11,75 @@
 #if USE_MP
 # include <mp.h>
 #endif
+#include <hal_proc.h>
 
 // === FLAGS ===
 #define DEBUG_TRACE_SWITCH	0
+#define DEBUG_DISABLE_DOUBLEFAULT	1
+#define DEBUG_VERY_SLOW_PERIOD	0
 
 // === CONSTANTS ===
-#define	SWITCH_MAGIC	0xFFFACE55	// There is no code in this area
 // Base is 1193182
 #define TIMER_BASE      1193182
-#define TIMER_DIVISOR   11931	//~100Hz
+#if DEBUG_VERY_SLOW_PERIOD
+# define TIMER_DIVISOR	1193	//~10Hz switch, with 10 quantum = 1s per thread
+#else
+# define TIMER_DIVISOR	11932	//~100Hz
+#endif
 
 // === TYPES ===
-#if USE_MP
 typedef struct sCPU
 {
 	Uint8	APICID;
 	Uint8	State;	// 0: Unavaliable, 1: Idle, 2: Active
 	Uint16	Resvd;
 	tThread	*Current;
-	tThread	*IdleThread;
 }	tCPU;
-#endif
 
 // === IMPORTS ===
 extern tGDT	gGDT[];
 extern tIDT	gIDT[];
-extern void APWait(void);	// 16-bit AP pause code
-extern void APStartup(void);	// 16-bit AP startup code
+extern void	APWait(void);	// 16-bit AP pause code
+extern void	APStartup(void);	// 16-bit AP startup code
 extern Uint	GetEIP(void);	// start.asm
-extern int	GetCPUNum(void);	// start.asm
+extern Uint	GetEIP_Sched(void);	// proc.asm
+extern void	NewTaskHeader(tThread *Thread, void *Fcn, int nArgs, ...);	// Actually takes cdecl args
+extern Uint	Proc_CloneInt(Uint *ESP, Uint32 *CR3);
 extern Uint32	gaInitPageDir[1024];	// start.asm
-extern void	Kernel_Stack_Top;
-extern tSpinlock	glThreadListLock;
+extern char	Kernel_Stack_Top[];
 extern int	giNumCPUs;
 extern int	giNextTID;
-extern int	giTotalTickets;
-extern int	giNumActiveThreads;
 extern tThread	gThreadZero;
-extern tThread	*gActiveThreads;
-extern tThread	*gSleepingThreads;
-extern tThread	*gDeleteThreads;
-extern void	Threads_Dump(void);
-extern tThread	*Threads_CloneTCB(Uint *Err, Uint Flags);
 extern void	Isr8(void);	// Double Fault
-extern void	Proc_ReturnToUser(void);
+extern void	Proc_ReturnToUser(tVAddr Handler, Uint Argument, tVAddr KernelStack);
+extern char	scheduler_return[];	// Return address in SchedulerBase
+extern char	IRQCommon[];	// Common IRQ handler code
+extern char	IRQCommon_handled[];	// IRQCommon call return location
+extern char	GetEIP_Sched_ret[];	// GetEIP call return location
+extern void	SwitchTasks(Uint NewSP, Uint *OldSP, Uint NewIP, Uint *OldIO, Uint CR3);
+extern void	Proc_InitialiseSSE(void);
+extern void	Proc_SaveSSE(Uint DestPtr);
+extern void	Proc_DisableSSE(void);
 
 // === PROTOTYPES ===
-void	ArchThreads_Init(void);
+//void	ArchThreads_Init(void);
 #if USE_MP
 void	MP_StartAP(int CPU);
+void	MP_SendIPIVector(int CPU, Uint8 Vector);
 void	MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
 #endif
-void	Proc_Start(void);
-tThread	*Proc_GetCurThread(void);
+void	Proc_IdleThread(void *Ptr);
+//void	Proc_Start(void);
+//tThread	*Proc_GetCurThread(void);
 void	Proc_ChangeStack(void);
- int	Proc_Clone(Uint *Err, Uint Flags);
-void	Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP);
-void	Proc_CallFaultHandler(tThread *Thread);
+// int	Proc_NewKThread(void (*Fcn)(void*), void *Data);
+// int	Proc_Clone(Uint *Err, Uint Flags);
+Uint	Proc_MakeUserStack(void);
+//void	Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize);
+void	Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP) NORETURN;
+ int	Proc_Demote(Uint *Err, int Dest, tRegs *Regs);
+//void	Proc_CallFaultHandler(tThread *Thread);
+//void	Proc_DumpThreadCPUState(tThread *Thread);
 void	Proc_Scheduler(int CPU);
 
 // === GLOBALS ===
@@ -78,16 +90,12 @@ tMPInfo	*gMPFloatPtr = NULL;
 volatile Uint32	giMP_TimerCount;	// Start Count for Local APIC Timer
 tAPIC	*gpMP_LocalAPIC = NULL;
 Uint8	gaAPIC_to_CPU[256] = {0};
-tCPU	gaCPUs[MAX_CPUS];
-tTSS	gaTSSs[MAX_CPUS];	// TSS Array
  int	giProc_BootProcessorID = 0;
-#else
-tThread	*gCurrentThread = NULL;
-tThread	*gpIdleThread = NULL;
-#endif
-#if USE_PAE
-Uint32	*gPML4s[4] = NULL;
+tTSS	gaTSSs[MAX_CPUS];	// TSS Array
 #endif
+tCPU	gaCPUs[MAX_CPUS] = {
+	{.Current = &gThreadZero}
+	};
 tTSS	*gTSSs = NULL;	// Pointer to TSS array
 tTSS	gTSS0 = {0};
 // --- Error Recovery ---
@@ -157,6 +165,7 @@ void ArchThreads_Init(void)
 	{
 		 int	i;
 	 	tMPTable_Ent	*ents;
+		#if DUMP_MP_TABLE
 		Log("gMPFloatPtr = %p", gMPFloatPtr);
 		Log("*gMPFloatPtr = {");
 		Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
@@ -170,8 +179,10 @@ void ArchThreads_Init(void)
 			gMPFloatPtr->Features[4]
 			);
 		Log("}");
-		
+		#endif		
+
 		mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
+		#if DUMP_MP_TABLE
 		Log("mptable = %p", mptable);
 		Log("*mptable = {");
 		Log("\t.Sig = 0x%08x", mptable->Sig);
@@ -187,6 +198,7 @@ void ArchThreads_Init(void)
 		Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
 		Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
 		Log("}");
+		#endif
 		
 		gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
 		
@@ -200,13 +212,14 @@ void ArchThreads_Init(void)
 			{
 			case 0:	// Processor
 				entSize = 20;
+				#if DUMP_MP_TABLE
 				Log("%i: Processor", i);
 				Log("\t.APICID = %i", ents->Proc.APICID);
 				Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
 				Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
 				Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
 				Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
-				
+				#endif
 				
 				if( !(ents->Proc.CPUFlags & 1) ) {
 					Log("DISABLED");
@@ -232,7 +245,7 @@ void ArchThreads_Init(void)
 				
 				break;
 			
-			#if DUMP_MP_TABLES
+			#if DUMP_MP_TABLE >= 2
 			case 1:	// Bus
 				entSize = 8;
 				Log("%i: Bus", i);
@@ -289,10 +302,9 @@ void ArchThreads_Init(void)
 	#else
 	giNumCPUs = 1;
 	gTSSs = &gTSS0;
-	MM_FinishVirtualInit();
 	#endif
 	
-	#if 0
+	#if !DEBUG_DISABLE_DOUBLEFAULT
 	// Initialise Double Fault TSS
 	gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
 	gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
@@ -310,6 +322,11 @@ void ArchThreads_Init(void)
 	outb(0x40, TIMER_DIVISOR&0xFF);	// Low Byte of Divisor
 	outb(0x40, (TIMER_DIVISOR>>8)&0xFF);	// High Byte
 	
+	Log_Debug("Proc", "PIT Frequency %i.%03i Hz",
+		TIMER_BASE/TIMER_DIVISOR,
+		((Uint64)TIMER_BASE*1000/TIMER_DIVISOR)%1000
+		);
+	
 	#if USE_MP
 	// Get the count setting for APIC timer
 	Log("Determining APIC Count");
@@ -319,8 +336,8 @@ void ArchThreads_Init(void)
 	Log("APIC Count %i", giMP_TimerCount);
 	{
 		Uint64	freq = giMP_TimerCount;
-		freq /= TIMER_DIVISOR;
 		freq *= TIMER_BASE;
+		freq /= TIMER_DIVISOR;
 		if( (freq /= 1000) < 2*1000)
 			Log("Bus Frequency %i KHz", freq);
 		else if( (freq /= 1000) < 2*1000)
@@ -340,7 +357,7 @@ void ArchThreads_Init(void)
 		gTSSs[pos].SS0 = 0x10;
 		gTSSs[pos].ESP0 = 0;	// Set properly by scheduler
 		gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
-		gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
+		gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos]) >> 16) & 0xFFFF;
 		gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
 	#if USE_MP
 	}
@@ -348,38 +365,40 @@ void ArchThreads_Init(void)
 	
 	// Load the BSP's TSS
 	__asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
+	// Set Current Thread and CPU Number in DR0 and DR1
+	__asm__ __volatile__ ("mov %0, %%db0"::"r"(&gThreadZero));
+	__asm__ __volatile__ ("mov %0, %%db1"::"r"(0));
 	
-	#if USE_MP
 	gaCPUs[0].Current = &gThreadZero;
-	#else
-	gCurrentThread = &gThreadZero;
-	#endif
 	gThreadZero.CurCPU = 0;
 	
-	#if USE_PAE
-	gThreadZero.MemState.PDP[0] = 0;
-	gThreadZero.MemState.PDP[1] = 0;
-	gThreadZero.MemState.PDP[2] = 0;
-	#else
 	gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
-	#endif
 	
 	// Create Per-Process Data Block
-	MM_Allocate(MM_PPD_CFG);
+	if( !MM_Allocate(MM_PPD_CFG) )
+	{
+		Panic("OOM - No space for initial Per-Process Config");
+	}
+
+	// Initialise SSE support
+	Proc_InitialiseSSE();
 	
 	// Change Stacks
 	Proc_ChangeStack();
 }
 
 #if USE_MP
+/**
+ * \brief Start an AP
+ */
 void MP_StartAP(int CPU)
 {
-	Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
+	Log_Log("Proc", "Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
 	
 	// Set location of AP startup code and mark for a warm restart
 	*(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
 	*(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
-	outb(0x70, 0x0F);	outb(0x71, 0x0A);	// Warm Reset
+	outb(0x70, 0x0F);	outb(0x71, 0x0A);	// Set warm reset flag
 	MP_SendIPI(gaCPUs[CPU].APICID, 0, 5);	// Init IPI
 	
 	// Delay
@@ -398,11 +417,17 @@ void MP_StartAP(int CPU)
 	giNumInitingCPUs ++;
 }
 
+void MP_SendIPIVector(int CPU, Uint8 Vector)
+{
+	MP_SendIPI(gaCPUs[CPU].APICID, Vector, 0);
+}
+
 /**
  * \brief Send an Inter-Processor Interrupt
  * \param APICID	Processor's Local APIC ID
  * \param Vector	Argument of some kind
- * \param DeliveryMode	Type of signal?
+ * \param DeliveryMode	Type of signal
+ * \note 3A 10.5 "APIC/Handling Local Interrupts"
  */
 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
 {
@@ -410,21 +435,35 @@ void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
 	
 	// Hi
 	val = (Uint)APICID << 24;
-	Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
+//	Log("%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
 	gpMP_LocalAPIC->ICR[1].Val = val;
 	// Low (and send)
 	val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
-	Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
+//	Log("%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
 	gpMP_LocalAPIC->ICR[0].Val = val;
 }
 #endif
 
+void Proc_IdleThread(void *Ptr)
+{
+	tCPU	*cpu = &gaCPUs[GetCPUNum()];
+	cpu->Current->ThreadName = strdup("Idle Thread");
+	Threads_SetPriority( cpu->Current, -1 );	// Never called randomly
+	cpu->Current->Quantum = 1;	// 1 slice quantum
+	for(;;) {
+		__asm__ __volatile__ ("sti");	// Make sure interrupts are enabled
+		__asm__ __volatile__ ("hlt");	// Make sure interrupts are enabled
+		Proc_Reschedule();
+	}
+}
+
 /**
  * \fn void Proc_Start(void)
  * \brief Start process scheduler
  */
 void Proc_Start(void)
 {
+	 int	tid;
 	#if USE_MP
 	 int	i;
 	#endif
@@ -433,16 +472,10 @@ void Proc_Start(void)
 	// Start APs
 	for( i = 0; i < giNumCPUs; i ++ )
 	{
+		if(i)	gaCPUs[i].Current = NULL;
+		
 		// Create Idle Task
-		if(Proc_Clone(0, 0) == 0)
-		{
-			gaCPUs[i].IdleThread = Proc_GetCurThread();
-			gaCPUs[i].IdleThread->ThreadName = "Idle Thread";
-			gaCPUs[i].IdleThread->NumTickets = 0;	// Never called randomly
-			gaCPUs[i].IdleThread->Quantum = 1;	// 1 slice quantum
-			for(;;)	HALT();	// Just yeilds
-		}
-		gaCPUs[i].Current = NULL;
+		tid = Proc_NewKThread(Proc_IdleThread, &gaCPUs[i]);
 		
 		// Start the AP
 		if( i != giProc_BootProcessorID ) {
@@ -454,27 +487,21 @@ void Proc_Start(void)
 	gaCPUs[0].Current = &gThreadZero;
 	
 	// Start interrupts and wait for APs to come up
-	Log("Waiting for APs to come up\n");
+	Log_Debug("Proc", "Waiting for APs to come up");
 	__asm__ __volatile__ ("sti");
 	while( giNumInitingCPUs )	__asm__ __volatile__ ("hlt");
-	MM_FinishVirtualInit();
 	#else
 	// Create Idle Task
-	if(Proc_Clone(0, 0) == 0)
-	{
-		gpIdleThread = Proc_GetCurThread();
-		gpIdleThread->ThreadName = "Idle Thread";
-		gpIdleThread->NumTickets = 0;	// Never called randomly
-		gpIdleThread->Quantum = 1;	// 1 slice quantum
-		for(;;)	HALT();	// Just yeilds
-	}
+	tid = Proc_NewKThread(Proc_IdleThread, &gaCPUs[0]);
+//	gaCPUs[0].IdleThread = Threads_GetThread(tid);
 	
 	// Set current task
-	gCurrentThread = &gThreadZero;
-	
+	gaCPUs[0].Current = &gThreadZero;
+
 	// Start Interrupts (and hence scheduler)
 	__asm__ __volatile__("sti");
 	#endif
+	MM_FinishVirtualInit();
 }
 
 /**
@@ -484,10 +511,9 @@ void Proc_Start(void)
 tThread *Proc_GetCurThread(void)
 {
 	#if USE_MP
-	//return gaCPUs[ gaAPIC_to_CPU[gpMP_LocalAPIC->ID.Val&0xFF] ].Current;
 	return gaCPUs[ GetCPUNum() ].Current;
 	#else
-	return gCurrentThread;
+	return gaCPUs[ 0 ].Current;
 	#endif
 }
 
@@ -542,74 +568,93 @@ void Proc_ChangeStack(void)
 	__asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
 }
 
+void Proc_ClearThread(tThread *Thread)
+{
+	Log_Warning("Proc", "TODO: Nuke address space etc");
+	if(Thread->SavedState.SSE) {
+		free(Thread->SavedState.SSE);
+		Thread->SavedState.SSE = NULL;
+	}
+}
+
+int Proc_NewKThread(void (*Fcn)(void*), void *Data)
+{
+	Uint	esp;
+	tThread	*newThread, *cur;
+	
+	cur = Proc_GetCurThread();
+	newThread = Threads_CloneTCB(0);
+	if(!newThread)	return -1;
+	
+	// Set CR3
+	newThread->MemState.CR3 = cur->MemState.CR3;
+
+	// Create new KStack
+	newThread->KernelStack = MM_NewKStack();
+	// Check for errors
+	if(newThread->KernelStack == 0) {
+		free(newThread);
+		return -1;
+	}
+
+	esp = newThread->KernelStack;
+	*(Uint*)(esp-=4) = (Uint)Data;	// Data (shadowed)
+	*(Uint*)(esp-=4) = 1;	// Number of params
+	*(Uint*)(esp-=4) = (Uint)Fcn;	// Function to call
+	*(Uint*)(esp-=4) = (Uint)newThread;	// Thread ID
+	
+	newThread->SavedState.ESP = esp;
+	newThread->SavedState.EIP = (Uint)&NewTaskHeader;
+	newThread->SavedState.SSE = NULL;
+//	Log("New (KThread) %p, esp = %p", newThread->SavedState.EIP, newThread->SavedState.ESP);
+	
+//	MAGIC_BREAK();	
+	Threads_AddActive(newThread);
+
+	return newThread->TID;
+}
+
 /**
  * \fn int Proc_Clone(Uint *Err, Uint Flags)
  * \brief Clone the current process
  */
-int Proc_Clone(Uint *Err, Uint Flags)
+int Proc_Clone(Uint Flags)
 {
 	tThread	*newThread;
 	tThread	*cur = Proc_GetCurThread();
-	Uint	eip, esp, ebp;
-	
-	__asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
-	__asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
-	
-	newThread = Threads_CloneTCB(Err, Flags);
-	if(!newThread)	return -1;
-	
-	// Initialise Memory Space (New Addr space or kernel stack)
-	if(Flags & CLONE_VM) {
-		newThread->MemState.CR3 = MM_Clone();
-		newThread->KernelStack = cur->KernelStack;
-	} else {
-		Uint	tmpEbp, oldEsp = esp;
-
-		// Set CR3
-		newThread->MemState.CR3 = cur->MemState.CR3;
-
-		// Create new KStack
-		newThread->KernelStack = MM_NewKStack();
-		// Check for errors
-		if(newThread->KernelStack == 0) {
-			free(newThread);
-			return -1;
-		}
+	Uint	eip;
 
-		// Get ESP as a used size
-		esp = cur->KernelStack - esp;
-		// Copy used stack
-		memcpy( (void*)(newThread->KernelStack - esp), (void*)(cur->KernelStack - esp), esp );
-		// Get ESP as an offset in the new stack
-		esp = newThread->KernelStack - esp;
-		// Adjust EBP
-		ebp = newThread->KernelStack - (cur->KernelStack - ebp);
-
-		// Repair EBPs & Stack Addresses
-		// Catches arguments also, but may trash stack-address-like values
-		for(tmpEbp = esp; tmpEbp < newThread->KernelStack; tmpEbp += 4)
-		{
-			if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < cur->KernelStack)
-				*(Uint*)tmpEbp += newThread->KernelStack - cur->KernelStack;
-		}
+	// Sanity, please
+	if( !(Flags & CLONE_VM) ) {
+		Log_Error("Proc", "Proc_Clone: Don't leave CLONE_VM unset, use Proc_NewKThread instead");
+		return -1;
 	}
 	
-	// Save core machine state
-	newThread->SavedState.ESP = esp;
-	newThread->SavedState.EBP = ebp;
-	eip = GetEIP();
-	if(eip == SWITCH_MAGIC) {
-		outb(0x20, 0x20);	// ACK Timer and return as child
-		__asm__ __volatile__ ("sti");	// Restart interrupts
+	// New thread
+	newThread = Threads_CloneTCB(Flags);
+	if(!newThread)	return -1;
+
+	newThread->KernelStack = cur->KernelStack;
+
+	// Clone state
+	eip = Proc_CloneInt(&newThread->SavedState.ESP, &newThread->MemState.CR3);
+	if( eip == 0 ) {
+		// ACK the interrupt
 		return 0;
 	}
-	
-	// Set EIP as parent
 	newThread->SavedState.EIP = eip;
+	newThread->SavedState.SSE = NULL;
+	newThread->SavedState.bSSEModified = 0;
 	
-	// Lock list and add to active
+	// Check for errors
+	if( newThread->MemState.CR3 == 0 ) {
+		Log_Error("Proc", "Proc_Clone: MM_Clone failed");
+		Threads_Delete(newThread);
+		return -1;
+	}
+
+	// Add the new thread to the run queue
 	Threads_AddActive(newThread);
-	
 	return newThread->TID;
 }
 
@@ -617,45 +662,35 @@ int Proc_Clone(Uint *Err, Uint Flags)
  * \fn int Proc_SpawnWorker(void)
  * \brief Spawns a new worker thread
  */
-int Proc_SpawnWorker(void)
+int Proc_SpawnWorker(void (*Fcn)(void*), void *Data)
 {
-	tThread	*new, *cur;
-	Uint	eip, esp, ebp;
-	
-	cur = Proc_GetCurThread();
+	tThread	*new;
+	Uint	stack_contents[4];
 	
 	// Create new thread
-	new = malloc( sizeof(tThread) );
+	new = Threads_CloneThreadZero();
 	if(!new) {
 		Warning("Proc_SpawnWorker - Out of heap space!\n");
 		return -1;
 	}
-	memcpy(new, &gThreadZero, sizeof(tThread));
-	// Set Thread ID
-	new->TID = giNextTID++;
-	// Create a new worker stack (in PID0's address space)
-	// The stack is relocated by this code
-	new->KernelStack = MM_NewWorkerStack();
 
-	// Get ESP and EBP based in the new stack
-	__asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
-	__asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
-	esp = new->KernelStack - (cur->KernelStack - esp);
-	ebp = new->KernelStack - (cur->KernelStack - ebp);	
+	// Create the stack contents
+	stack_contents[3] = (Uint)Data;
+	stack_contents[2] = 1;
+	stack_contents[1] = (Uint)Fcn;
+	stack_contents[0] = (Uint)new;
 	
+	// Create a new worker stack (in PID0's address space)
+	new->KernelStack = MM_NewWorkerStack(stack_contents, sizeof(stack_contents));
+
 	// Save core machine state
-	new->SavedState.ESP = esp;
-	new->SavedState.EBP = ebp;
-	eip = GetEIP();
-	if(eip == SWITCH_MAGIC) {
-		outb(0x20, 0x20);	// ACK Timer and return as child
-		return 0;
-	}
+	new->SavedState.ESP = new->KernelStack - sizeof(stack_contents);
+	new->SavedState.EIP = (Uint)NewTaskHeader;
+	new->SavedState.SSE = NULL;
+	new->SavedState.bSSEModified = 0;
 	
-	// Set EIP as parent
-	new->SavedState.EIP = eip;
 	// Mark as active
-	new->Status = THREAD_STAT_ACTIVE;
+	new->Status = THREAD_STAT_PREINIT;
 	Threads_AddActive( new );
 	
 	return new->TID;
@@ -679,57 +714,48 @@ Uint Proc_MakeUserStack(void)
 	
 	// Allocate Stack - Allocate incrementally to clean up MM_Dump output
 	for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
-		MM_Allocate( base + (i<<12) );
+	{
+		if( !MM_Allocate( base + (i<<12) ) )
+		{
+			Warning("OOM: Proc_MakeUserStack");
+			return 0;
+		}
+	}
 	
 	return base + USER_STACK_SZ;
 }
 
-/**
- * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
- * \brief Starts a user task
- */
-void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
+void Proc_StartUser(Uint Entrypoint, Uint Base, int ArgC, char **ArgV, int DataSize)
 {
-	Uint	*stack = (void*)Proc_MakeUserStack();
+	Uint	*stack;
 	 int	i;
-	Uint	delta;
+	char	**envp = NULL;
 	Uint16	ss, cs;
 	
-	//Log("stack = %p", stack);
-	
-	// Copy Arguments
+	// Copy data to the user stack and free original buffer
+	stack = (void*)Proc_MakeUserStack();
 	stack -= DataSize/sizeof(*stack);
 	memcpy( stack, ArgV, DataSize );
+	free(ArgV);
 	
-	//Log("stack = %p", stack);
-	
+	// Adjust Arguments and environment
 	if( DataSize )
 	{
-		// Adjust Arguments and environment
-		delta = (Uint)stack - (Uint)ArgV;
+		Uint delta = (Uint)stack - (Uint)ArgV;
 		ArgV = (char**)stack;
-		for( i = 0; ArgV[i]; i++ )
-			ArgV[i] += delta;
-		i ++;
-		
-		// Do we care about EnvP?
-		if( EnvP ) {
-			EnvP = &ArgV[i];
-			for( i = 0; EnvP[i]; i++ )
-				EnvP[i] += delta;
-		}
+		for( i = 0; ArgV[i]; i++ )	ArgV[i] += delta;
+		envp = &ArgV[i+1];
+		for( i = 0; envp[i]; i++ )	envp[i] += delta;
 	}
 	
 	// User Mode Segments
 	ss = 0x23;	cs = 0x1B;
 	
 	// Arguments
-	*--stack = (Uint)EnvP;
+	*--stack = (Uint)envp;
 	*--stack = (Uint)ArgV;
 	*--stack = (Uint)ArgC;
-	while(*Bases)
-		*--stack = *Bases++;
-	*--stack = 0;	// Return Address
+	*--stack = Base;
 	
 	Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
 }
@@ -810,131 +836,186 @@ void Proc_CallFaultHandler(tThread *Thread)
 {
 	// Rewinds the stack and calls the user function
 	// Never returns
-	__asm__ __volatile__ ("mov %0, %%ebp;\n\tcall Proc_ReturnToUser" :: "r"(Thread->FaultHandler));
+	Proc_ReturnToUser( Thread->FaultHandler, Thread->CurFaultNum, Thread->KernelStack );
 	for(;;);
 }
 
+void Proc_DumpThreadCPUState(tThread *Thread)
+{
+	if( Thread->CurCPU > -1 )
+	{
+		 int	maxBacktraceDistance = 6;
+		tRegs	*regs = NULL;
+		Uint32	*stack;
+		
+		if( Thread->CurCPU != GetCPUNum() ) {
+			Log("  Currently running");
+			return ;
+		}
+		
+		// Backtrace to find the IRQ entrypoint
+		// - This will usually only be called by an IRQ, so this should
+		//   work
+		__asm__ __volatile__ ("mov %%ebp, %0" : "=r" (stack));
+		while( maxBacktraceDistance -- )
+		{
+			// [ebp] = oldEbp
+			// [ebp+4] = retaddr
+			
+			if( stack[1] == (tVAddr)&IRQCommon_handled ) {
+				regs = (void*)stack[2];
+				break;
+			}
+			
+			stack = (void*)stack[0];
+		}
+		
+		if( !regs ) {
+			Log("  Unable to find IRQ Entry");
+			return ;
+		}
+		
+		Log("  at %04x:%08x", regs->cs, regs->eip);
+		return ;
+	}
+	
+	tVAddr	diffFromScheduler = Thread->SavedState.EIP - (tVAddr)SwitchTasks;
+	tVAddr	diffFromClone = Thread->SavedState.EIP - (tVAddr)Proc_CloneInt;
+	tVAddr	diffFromSpawn = Thread->SavedState.EIP - (tVAddr)NewTaskHeader;
+	
+	if( diffFromClone > 0 && diffFromClone < 40 )	// When I last checked, .newTask was at .+27
+	{
+		Log("  Creating process");
+		return ;
+	}
+	
+	if( diffFromSpawn == 0 )
+	{
+		Log("  Creating thread");
+		return ;
+	}
+	
+	if( diffFromScheduler > 0 && diffFromScheduler < 128 )	// When I last checked, GetEIP was at .+0x30
+	{
+		// Scheduled out
+		Log("  At %04x:%08x", Thread->SavedState.UserCS, Thread->SavedState.UserEIP);
+		return ;
+	}
+	
+	Log("  Just created (unknown %p)", Thread->SavedState.EIP);
+}
+
+void Proc_Reschedule(void)
+{
+	tThread	*nextthread, *curthread;
+	 int	cpu = GetCPUNum();
+
+	// TODO: Wait for the lock?
+	if(IS_LOCKED(&glThreadListLock))        return;
+	
+	curthread = Proc_GetCurThread();
+
+	nextthread = Threads_GetNextToRun(cpu, curthread);
+
+	if(!nextthread || nextthread == curthread)
+		return ;
+
+	#if DEBUG_TRACE_SWITCH
+	// HACK: Ignores switches to the idle threads
+	if( nextthread->TID == 0 || nextthread->TID > giNumCPUs )
+	{
+		LogF("\nSwitching CPU %i to %p (%i %s) - CR3 = 0x%x, EIP = %p, ESP = %p\n",
+			GetCPUNum(),
+			nextthread, nextthread->TID, nextthread->ThreadName,
+			nextthread->MemState.CR3,
+			nextthread->SavedState.EIP,
+			nextthread->SavedState.ESP
+			);
+	}
+	#endif
+
+	// Update CPU state
+	gaCPUs[cpu].Current = nextthread;
+	gTSSs[cpu].ESP0 = nextthread->KernelStack-4;
+	__asm__ __volatile__("mov %0, %%db0\n\t" : : "r"(nextthread) );
+
+	// Save FPU/MMX/XMM/SSE state
+	if( curthread && curthread->SavedState.SSE )
+	{
+		Proc_SaveSSE( ((Uint)curthread->SavedState.SSE + 0xF) & ~0xF );
+		curthread->SavedState.bSSEModified = 0;
+		Proc_DisableSSE();
+	}
+
+	if( curthread )
+	{
+		SwitchTasks(
+			nextthread->SavedState.ESP, &curthread->SavedState.ESP,
+			nextthread->SavedState.EIP, &curthread->SavedState.EIP,
+			nextthread->MemState.CR3
+			);
+	}
+	else
+	{
+		SwitchTasks(
+			nextthread->SavedState.ESP, 0,
+			nextthread->SavedState.EIP, 0,
+			nextthread->MemState.CR3
+			);
+	}
+
+	return ;
+}
+
 /**
  * \fn void Proc_Scheduler(int CPU)
  * \brief Swap current thread and clears dead threads
  */
 void Proc_Scheduler(int CPU)
 {
-	Uint	esp, ebp, eip;
 	tThread	*thread;
 	
 	// If the spinlock is set, let it complete
 	if(IS_LOCKED(&glThreadListLock))	return;
 	
-	// Clear Delete Queue
-	while(gDeleteThreads)
-	{
-		thread = gDeleteThreads->Next;
-		if(gDeleteThreads->IsLocked) {	// Only free if structure is unused
-			gDeleteThreads->Status = THREAD_STAT_NULL;
-			free( gDeleteThreads );
-		}
-		gDeleteThreads = thread;
-	}
-	
-	// Check if there is any tasks running
-	if(giNumActiveThreads == 0) {
-		#if 0
-		Log("No Active threads, sleeping");
-		#endif
-		#if USE_MP
-		if(CPU)
-			gpMP_LocalAPIC->EOI.Val = 0;
-		else
-		#endif
-			outb(0x20, 0x20);
-		__asm__ __volatile__ ("hlt");
-		return;
-	}
-	
 	// Get current thread
-	#if USE_MP
 	thread = gaCPUs[CPU].Current;
-	#else
-	thread = gCurrentThread;
-	#endif
 	
 	if( thread )
 	{
+		tRegs	*regs;
+		Uint	ebp;
 		// Reduce remaining quantum and continue timeslice if non-zero
-		if(thread->Remaining--)	return;
+		if( thread->Remaining-- )
+			return;
 		// Reset quantum for next call
 		thread->Remaining = thread->Quantum;
 		
-		// Get machine state
-		__asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
-		__asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
-		eip = GetEIP();
-		if(eip == SWITCH_MAGIC)	return;	// Check if a switch happened
+		// TODO: Make this more stable somehow
+		__asm__ __volatile__("mov %%ebp, %0" : "=r" (ebp));
+		regs = (tRegs*)(ebp+(2+2)*4);	// EBP,Ret + CPU,CurThread
+		thread->SavedState.UserCS = regs->cs;
+		thread->SavedState.UserEIP = regs->eip;
 		
-		// Save machine state
-		thread->SavedState.ESP = esp;
-		thread->SavedState.EBP = ebp;
-		thread->SavedState.EIP = eip;
-	}
-	
-	// Get next thread to run
-	thread = Threads_GetNextToRun(CPU, thread);
-	
-	// No avaliable tasks, just go into low power mode
-	if(thread == NULL) {
-		//HALT();
-		//return;
-		#if USE_MP
-		thread = gaCPUs[CPU].IdleThread;
-		#else
-		thread = gpIdleThread;
-		#endif
+		if(thread->bInstrTrace) {
+			regs->eflags |= 0x100;	// Set TF
+			Log("%p De-scheduled", thread);
+		}
+		else
+			regs->eflags &= ~0x100;	// Clear TF
 	}
-	
-	#if DEBUG_TRACE_SWITCH
-	Log("Switching to task %i, CR3 = 0x%x, EIP = %p",
-		thread->TID,
-		thread->MemState.CR3,
-		thread->SavedState.EIP
-		);
-	#endif
-	
-	// Set current thread
+
+#if 0
+	// TODO: Ack timer?
 	#if USE_MP
-	gaCPUs[CPU].Current = thread;
-	#else
-	gCurrentThread = thread;
-	#endif
-	
-	//Log("CPU = %i", CPU);
-	
-	// Update Kernel Stack pointer
-	gTSSs[CPU].ESP0 = thread->KernelStack-4;
-	
-	// Set address space
-	#if USE_PAE
-	# error "Todo: Implement PAE Address space switching"
-	#else
-		__asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
-	#endif
-	
-	#if 0
-	if(thread->SavedState.ESP > 0xC0000000
-	&& thread->SavedState.ESP < thread->KernelStack-0x2000) {
-		Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
-	}
+	if( GetCPUNum() )
+		gpMP_LocalAPIC->EOI.Val = 0;
+	else
 	#endif
-	
-	// Switch threads
-	__asm__ __volatile__ (
-		"mov %1, %%esp\n\t"	// Restore ESP
-		"mov %2, %%ebp\n\t"	// and EBP
-		"jmp *%3" : :	// And return to where we saved state (Proc_Clone or Proc_Scheduler)
-		"a"(SWITCH_MAGIC), "b"(thread->SavedState.ESP),
-		"d"(thread->SavedState.EBP), "c"(thread->SavedState.EIP)
-		);
-	for(;;);	// Shouldn't reach here
+		outb(0x20, 0x20);
+	__asm__ __volatile__ ("sti");
+	Proc_Reschedule();
+#endif
 }
 
 // === EXPORTS ===