2 * AcessOS Microkernel Version
15 #define DEBUG_TRACE_SWITCH 0
18 #define SWITCH_MAGIC 0xFFFACE55 // There is no code in this area
20 #define TIMER_DIVISOR 11931 //~100Hz
27 Uint8 State; // 0: Unavaliable, 1: Idle, 2: Active
36 extern void APWait(void); // 16-bit AP pause code
37 extern void APStartup(void); // 16-bit AP startup code
38 extern Uint GetEIP(void); // start.asm
39 extern int GetCPUNum(void); // start.asm
40 extern Uint32 gaInitPageDir[1024]; // start.asm
41 extern void Kernel_Stack_Top;
42 extern tSpinlock glThreadListLock;
45 extern int giTotalTickets;
46 extern int giNumActiveThreads;
47 extern tThread gThreadZero;
48 extern tThread *gActiveThreads;
49 extern tThread *gSleepingThreads;
50 extern tThread *gDeleteThreads;
51 extern tThread *Threads_GetNextToRun(int CPU);
52 extern void Threads_Dump(void);
53 extern tThread *Threads_CloneTCB(Uint *Err, Uint Flags);
54 extern void Isr8(void); // Double Fault
55 extern void Proc_ReturnToUser(void);
58 void ArchThreads_Init(void);
60 void MP_StartAP(int CPU);
61 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
63 void Proc_Start(void);
64 tThread *Proc_GetCurThread(void);
65 void Proc_ChangeStack(void);
66 int Proc_Clone(Uint *Err, Uint Flags);
67 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP);
68 void Proc_CallFaultHandler(tThread *Thread);
69 void Proc_Scheduler(int CPU);
72 // --- Multiprocessing ---
74 volatile int giNumInitingCPUs = 0;
75 tMPInfo *gMPFloatPtr = NULL;
76 tAPIC *gpMP_LocalAPIC = NULL;
77 Uint8 gaAPIC_to_CPU[256] = {0};
78 tCPU gaCPUs[MAX_CPUS];
79 int giProc_BootProcessorID = 0;
81 tThread *gCurrentThread = NULL;
84 Uint32 *gPML4s[4] = NULL;
88 // --- Error Recovery ---
89 char gaDoubleFaultStack[1024];
90 tTSS gDoubleFault_TSS = {
91 .ESP0 = (Uint)&gaDoubleFaultStack[1023],
93 .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
95 .ESP = (Uint)&gaDoubleFaultStack[1023],
96 .CS = 0x08, .SS = 0x10,
97 .DS = 0x10, .ES = 0x10,
98 .FS = 0x10, .GS = 0x10,
103 * \fn void ArchThreads_Init(void)
104 * \brief Starts the process scheduler
106 void ArchThreads_Init(void)
113 // Mark BSP as active
116 // -- Initialise Multiprocessing
117 // Find MP Floating Table
118 // - EBDA/Last 1Kib (640KiB)
119 for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
120 if( *(Uint*)(pos) == MPPTR_IDENT ) {
121 Log("Possible %p", pos);
122 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
123 gMPFloatPtr = (void*)pos;
127 // - Last KiB (512KiB base mem)
129 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
130 if( *(Uint*)(pos) == MPPTR_IDENT ) {
131 Log("Possible %p", pos);
132 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
133 gMPFloatPtr = (void*)pos;
140 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
141 if( *(Uint*)(pos) == MPPTR_IDENT ) {
142 Log("Possible %p", pos);
143 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
144 gMPFloatPtr = (void*)pos;
150 // If the MP Table Exists, parse it
155 Log("gMPFloatPtr = %p", gMPFloatPtr);
156 Log("*gMPFloatPtr = {");
157 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
158 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
159 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
160 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
161 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
162 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
163 gMPFloatPtr->Features[0], gMPFloatPtr->Features[1],
164 gMPFloatPtr->Features[2], gMPFloatPtr->Features[3],
165 gMPFloatPtr->Features[4]
169 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
170 Log("mptable = %p", mptable);
172 Log("\t.Sig = 0x%08x", mptable->Sig);
173 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
174 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
175 Log("\t.Checksum = 0x%02x", mptable->Checksum);
176 Log("\t.OEMID = '%8c'", mptable->OemID);
177 Log("\t.ProductID = '%8c'", mptable->ProductID);
178 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
179 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
180 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
181 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
182 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
183 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
186 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
188 ents = mptable->Entries;
191 for( i = 0; i < mptable->EntryCount; i ++ )
198 Log("%i: Processor", i);
199 Log("\t.APICID = %i", ents->Proc.APICID);
200 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
201 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
202 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
203 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
206 if( !(ents->Proc.CPUFlags & 1) ) {
211 // Check if there is too many processors
212 if(giNumCPUs >= MAX_CPUS) {
213 giNumCPUs ++; // If `giNumCPUs` > MAX_CPUS later, it will be clipped
217 // Initialise CPU Info
218 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
219 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
220 gaCPUs[giNumCPUs].State = 0;
224 if( ents->Proc.CPUFlags & 2 ) {
225 giProc_BootProcessorID = giNumCPUs-1;
232 Log("\t.ID = %i", ents->Bus.ID);
233 Log("\t.TypeString = '%6C'", ents->Bus.TypeString);
237 Log("%i: I/O APIC", i);
238 Log("\t.ID = %i", ents->IOAPIC.ID);
239 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
240 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
241 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
243 case 3: // I/O Interrupt Assignment
245 Log("%i: I/O Interrupt Assignment", i);
246 Log("\t.IntType = %i", ents->IOInt.IntType);
247 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
248 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
249 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
250 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
251 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
253 case 4: // Local Interrupt Assignment
255 Log("%i: Local Interrupt Assignment", i);
256 Log("\t.IntType = %i", ents->LocalInt.IntType);
257 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
258 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
259 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
260 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
261 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
264 Log("%i: Unknown (%i)", i, ents->Type);
267 ents = (void*)( (Uint)ents + entSize );
270 if( giNumCPUs > MAX_CPUS ) {
271 Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
272 giNumCPUs = MAX_CPUS;
276 Log("No MP Table was found, assuming uniprocessor\n");
283 MM_FinishVirtualInit();
286 // Initialise Double Fault TSS
287 gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
288 gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
289 gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
291 // Set double fault IDT to use the new TSS
292 gIDT[8].OffsetLo = 0;
294 gIDT[8].Flags = 0x8500;
295 gIDT[8].OffsetHi = 0;
298 // Initialise Normal TSS(s)
299 for(pos=0;pos<giNumCPUs;pos++)
304 gTSSs[pos].SS0 = 0x10;
305 gTSSs[pos].ESP0 = 0; // Set properly by scheduler
306 gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
307 gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
308 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
313 for( pos = 0; pos < giNumCPUs; pos ++ )
315 gaCPUs[pos].Current = NULL;
316 if( pos != giProc_BootProcessorID ) {
317 Log("Starting AP %i, (APIC %i)\n", pos, gaCPUs[pos].APICID);
322 Log("Waiting for APs to come up\n");
323 while( giNumInitingCPUs ) __asm__ __volatile__ ("hlt");
324 MM_FinishVirtualInit();
325 //Panic("Uh oh... MP Table Parsing is unimplemented\n");
328 // Load the BSP's TSS
329 __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
332 gaCPUs[0].Current = &gThreadZero;
334 gCurrentThread = &gThreadZero;
338 gThreadZero.MemState.PDP[0] = 0;
339 gThreadZero.MemState.PDP[1] = 0;
340 gThreadZero.MemState.PDP[2] = 0;
342 gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
345 // Set timer frequency
346 outb(0x43, 0x34); // Set Channel 0, Low/High, Rate Generator
347 outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
348 outb(0x40, (TIMER_DIVISOR>>8)&0xFF); // High Byte
350 // Create Per-Process Data Block
351 MM_Allocate(MM_PPD_CFG);
358 void MP_StartAP(int CPU)
360 Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
362 // Set location of AP startup code and mark for a warm restart
363 *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
364 *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
365 outb(0x70, 0x0F); outb(0x71, 0x0A); // Warm Reset
366 MP_SendIPI(gaCPUs[CPU].APICID, 0, 5); // Init IPI
369 inb(0x80); inb(0x80); inb(0x80); inb(0x80);
372 *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA; // Far JMP
373 *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0); // IP
374 *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF; // CS
375 // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
377 MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6); // StartupIPI
383 * \brief Send an Inter-Processor Interrupt
384 * \param APICID Processor's Local APIC ID
385 * \param Vector Argument of some kind
386 * \param DeliveryMode Type of signal?
388 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
390 Uint32 addr = (Uint)gpMP_LocalAPIC + 0x300;
394 val = (Uint)APICID << 24;
395 Log("*%p = 0x%08x", addr+0x10, val);
396 *(Uint32*)(addr+0x10) = val;
399 val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
400 Log("*%p = 0x%08x", addr, val);
401 *(Uint32*)addr = val;
406 * \fn void Proc_Start(void)
407 * \brief Start process scheduler
409 void Proc_Start(void)
411 // Start Interrupts (and hence scheduler)
412 __asm__ __volatile__("sti");
416 * \fn tThread *Proc_GetCurThread(void)
417 * \brief Gets the current thread
419 tThread *Proc_GetCurThread(void)
422 //return gaCPUs[ gaAPIC_to_CPU[gpMP_LocalAPIC->ID.Val&0xFF] ].Current;
423 return gaCPUs[ GetCPUNum() ].Current;
425 return gCurrentThread;
430 * \fn void Proc_ChangeStack(void)
431 * \brief Swaps the current stack for a new one (in the proper stack reigon)
433 void Proc_ChangeStack(void)
437 Uint curBase, newBase;
439 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
440 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
445 newBase = MM_NewKStack();
448 Panic("What the?? Unable to allocate space for initial kernel stack");
452 curBase = (Uint)&Kernel_Stack_Top;
454 LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
456 // Get ESP as a used size
458 LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
460 memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
461 // Get ESP as an offset in the new stack
464 ebp = newBase - (curBase - ebp);
466 // Repair EBPs & Stack Addresses
467 // Catches arguments also, but may trash stack-address-like values
468 for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
470 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
471 *(Uint*)tmpEbp += newBase - curBase;
474 Proc_GetCurThread()->KernelStack = newBase;
476 __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
477 __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
481 * \fn int Proc_Clone(Uint *Err, Uint Flags)
482 * \brief Clone the current process
484 int Proc_Clone(Uint *Err, Uint Flags)
487 tThread *cur = Proc_GetCurThread();
490 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
491 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
493 newThread = Threads_CloneTCB(Err, Flags);
494 if(!newThread) return -1;
496 // Initialise Memory Space (New Addr space or kernel stack)
497 if(Flags & CLONE_VM) {
498 newThread->MemState.CR3 = MM_Clone();
499 newThread->KernelStack = cur->KernelStack;
501 Uint tmpEbp, oldEsp = esp;
504 newThread->MemState.CR3 = cur->MemState.CR3;
507 newThread->KernelStack = MM_NewKStack();
509 if(newThread->KernelStack == 0) {
514 // Get ESP as a used size
515 esp = cur->KernelStack - esp;
517 memcpy( (void*)(newThread->KernelStack - esp), (void*)(cur->KernelStack - esp), esp );
518 // Get ESP as an offset in the new stack
519 esp = newThread->KernelStack - esp;
521 ebp = newThread->KernelStack - (cur->KernelStack - ebp);
523 // Repair EBPs & Stack Addresses
524 // Catches arguments also, but may trash stack-address-like values
525 for(tmpEbp = esp; tmpEbp < newThread->KernelStack; tmpEbp += 4)
527 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < cur->KernelStack)
528 *(Uint*)tmpEbp += newThread->KernelStack - cur->KernelStack;
532 // Save core machine state
533 newThread->SavedState.ESP = esp;
534 newThread->SavedState.EBP = ebp;
536 if(eip == SWITCH_MAGIC) {
537 outb(0x20, 0x20); // ACK Timer and return as child
542 newThread->SavedState.EIP = eip;
544 // Lock list and add to active
545 Threads_AddActive(newThread);
547 return newThread->TID;
551 * \fn int Proc_SpawnWorker(void)
552 * \brief Spawns a new worker thread
554 int Proc_SpawnWorker(void)
559 cur = Proc_GetCurThread();
562 new = malloc( sizeof(tThread) );
564 Warning("Proc_SpawnWorker - Out of heap space!\n");
567 memcpy(new, &gThreadZero, sizeof(tThread));
569 new->TID = giNextTID++;
570 // Create a new worker stack (in PID0's address space)
571 // The stack is relocated by this code
572 new->KernelStack = MM_NewWorkerStack();
574 // Get ESP and EBP based in the new stack
575 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
576 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
577 esp = new->KernelStack - (cur->KernelStack - esp);
578 ebp = new->KernelStack - (cur->KernelStack - ebp);
580 // Save core machine state
581 new->SavedState.ESP = esp;
582 new->SavedState.EBP = ebp;
584 if(eip == SWITCH_MAGIC) {
585 outb(0x20, 0x20); // ACK Timer and return as child
590 new->SavedState.EIP = eip;
592 new->Status = THREAD_STAT_ACTIVE;
593 Threads_AddActive( new );
599 * \fn Uint Proc_MakeUserStack(void)
600 * \brief Creates a new user stack
602 Uint Proc_MakeUserStack(void)
605 Uint base = USER_STACK_TOP - USER_STACK_SZ;
607 // Check Prospective Space
608 for( i = USER_STACK_SZ >> 12; i--; )
609 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
612 if(i != -1) return 0;
614 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
615 for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
616 MM_Allocate( base + (i<<12) );
618 return base + USER_STACK_SZ;
622 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
623 * \brief Starts a user task
625 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
627 Uint *stack = (void*)Proc_MakeUserStack();
632 //Log("stack = %p", stack);
635 stack -= DataSize/sizeof(*stack);
636 memcpy( stack, ArgV, DataSize );
638 //Log("stack = %p", stack);
642 // Adjust Arguments and environment
643 delta = (Uint)stack - (Uint)ArgV;
644 ArgV = (char**)stack;
645 for( i = 0; ArgV[i]; i++ )
649 // Do we care about EnvP?
652 for( i = 0; EnvP[i]; i++ )
657 // User Mode Segments
658 ss = 0x23; cs = 0x1B;
661 *--stack = (Uint)EnvP;
662 *--stack = (Uint)ArgV;
663 *--stack = (Uint)ArgC;
666 *--stack = 0; // Return Address
668 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
671 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
673 Uint *stack = (void*)Stack;
674 *--stack = SS; //Stack Segment
675 *--stack = Stack; //Stack Pointer
676 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
677 *--stack = CS; //Code Segment
680 *--stack = 0xAAAAAAAA; // eax
681 *--stack = 0xCCCCCCCC; // ecx
682 *--stack = 0xDDDDDDDD; // edx
683 *--stack = 0xBBBBBBBB; // ebx
684 *--stack = 0xD1D1D1D1; // edi
685 *--stack = 0x54545454; // esp - NOT POPED
686 *--stack = 0x51515151; // esi
687 *--stack = 0xB4B4B4B4; // ebp
694 __asm__ __volatile__ (
695 "mov %%eax,%%esp;\n\t" // Set stack pointer
701 "iret;\n\t" : : "a" (stack));
706 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
707 * \brief Demotes a process to a lower permission level
708 * \param Err Pointer to user's errno
709 * \param Dest New Permission Level
710 * \param Regs Pointer to user's register structure
712 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
714 int cpl = Regs->cs & 3;
716 if(Dest > 3 || Dest < 0) {
727 // Change the Segment Registers
728 Regs->cs = (((Dest+1)<<4) | Dest) - 8;
729 Regs->ss = ((Dest+1)<<4) | Dest;
730 // Check if the GP Segs are GDT, then change them
731 if(!(Regs->ds & 4)) Regs->ds = ((Dest+1)<<4) | Dest;
732 if(!(Regs->es & 4)) Regs->es = ((Dest+1)<<4) | Dest;
733 if(!(Regs->fs & 4)) Regs->fs = ((Dest+1)<<4) | Dest;
734 if(!(Regs->gs & 4)) Regs->gs = ((Dest+1)<<4) | Dest;
740 * \brief Calls a signal handler in user mode
741 * \note Used for signals
743 void Proc_CallFaultHandler(tThread *Thread)
745 // Rewinds the stack and calls the user function
747 __asm__ __volatile__ ("mov %0, %%ebp;\n\tcall Proc_ReturnToUser" :: "r"(Thread->FaultHandler));
752 * \fn void Proc_Scheduler(int CPU)
753 * \brief Swap current thread and clears dead threads
755 void Proc_Scheduler(int CPU)
760 // If the spinlock is set, let it complete
761 if(IS_LOCKED(&glThreadListLock)) return;
763 // Clear Delete Queue
764 while(gDeleteThreads)
766 thread = gDeleteThreads->Next;
767 if(gDeleteThreads->IsLocked) { // Only free if structure is unused
768 gDeleteThreads->Status = THREAD_STAT_NULL;
769 free( gDeleteThreads );
771 gDeleteThreads = thread;
774 // Check if there is any tasks running
775 if(giNumActiveThreads == 0) {
776 Log("No Active threads, sleeping");
777 __asm__ __volatile__ ("hlt");
781 // Get current thread
783 thread = gaCPUs[CPU].Current;
785 thread = gCurrentThread;
788 // Reduce remaining quantum and continue timeslice if non-zero
789 if(thread->Remaining--) return;
790 // Reset quantum for next call
791 thread->Remaining = thread->Quantum;
794 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
795 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
797 if(eip == SWITCH_MAGIC) return; // Check if a switch happened
799 // Save machine state
800 thread->SavedState.ESP = esp;
801 thread->SavedState.EBP = ebp;
802 thread->SavedState.EIP = eip;
805 thread = Threads_GetNextToRun(CPU);
809 Warning("Hmm... Threads_GetNextToRun returned NULL, I don't think this should happen.\n");
813 #if DEBUG_TRACE_SWITCH
814 Log("Switching to task %i, CR3 = 0x%x, EIP = %p",
816 thread->MemState.CR3,
817 thread->SavedState.EIP
821 // Set current thread
823 gaCPUs[CPU].Current = thread;
825 gCurrentThread = thread;
828 // Update Kernel Stack pointer
829 gTSSs[CPU].ESP0 = thread->KernelStack-4;
833 # error "Todo: Implement PAE Address space switching"
835 __asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
839 if(thread->SavedState.ESP > 0xC0000000
840 && thread->SavedState.ESP < thread->KernelStack-0x2000) {
841 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
846 __asm__ __volatile__ (
847 "mov %1, %%esp\n\t" // Restore ESP
848 "mov %2, %%ebp\n\t" // and EBP
849 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
850 "a"(SWITCH_MAGIC), "b"(thread->SavedState.ESP),
851 "d"(thread->SavedState.EBP), "c"(thread->SavedState.EIP)
853 for(;;); // Shouldn't reach here
857 EXPORT(Proc_SpawnWorker);