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 tTSS gaTSSs[MAX_CPUS]; // TSS Array
80 int giProc_BootProcessorID = 0;
82 tThread *gCurrentThread = NULL;
85 Uint32 *gPML4s[4] = NULL;
87 tTSS *gTSSs = NULL; // Pointer to TSS array
89 // --- Error Recovery ---
90 char gaDoubleFaultStack[1024];
91 tTSS gDoubleFault_TSS = {
92 .ESP0 = (Uint)&gaDoubleFaultStack[1023],
94 .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
96 .ESP = (Uint)&gaDoubleFaultStack[1023],
97 .CS = 0x08, .SS = 0x10,
98 .DS = 0x10, .ES = 0x10,
99 .FS = 0x10, .GS = 0x10,
104 * \fn void ArchThreads_Init(void)
105 * \brief Starts the process scheduler
107 void ArchThreads_Init(void)
114 // Mark BSP as active
117 // -- Initialise Multiprocessing
118 // Find MP Floating Table
119 // - EBDA/Last 1Kib (640KiB)
120 for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
121 if( *(Uint*)(pos) == MPPTR_IDENT ) {
122 Log("Possible %p", pos);
123 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
124 gMPFloatPtr = (void*)pos;
128 // - Last KiB (512KiB base mem)
130 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
131 if( *(Uint*)(pos) == MPPTR_IDENT ) {
132 Log("Possible %p", pos);
133 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
134 gMPFloatPtr = (void*)pos;
141 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
142 if( *(Uint*)(pos) == MPPTR_IDENT ) {
143 Log("Possible %p", pos);
144 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
145 gMPFloatPtr = (void*)pos;
151 // If the MP Table Exists, parse it
156 Log("gMPFloatPtr = %p", gMPFloatPtr);
157 Log("*gMPFloatPtr = {");
158 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
159 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
160 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
161 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
162 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
163 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
164 gMPFloatPtr->Features[0], gMPFloatPtr->Features[1],
165 gMPFloatPtr->Features[2], gMPFloatPtr->Features[3],
166 gMPFloatPtr->Features[4]
170 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
171 Log("mptable = %p", mptable);
173 Log("\t.Sig = 0x%08x", mptable->Sig);
174 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
175 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
176 Log("\t.Checksum = 0x%02x", mptable->Checksum);
177 Log("\t.OEMID = '%8c'", mptable->OemID);
178 Log("\t.ProductID = '%8c'", mptable->ProductID);
179 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
180 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
181 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
182 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
183 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
184 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
187 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
189 ents = mptable->Entries;
192 for( i = 0; i < mptable->EntryCount; i ++ )
199 Log("%i: Processor", i);
200 Log("\t.APICID = %i", ents->Proc.APICID);
201 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
202 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
203 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
204 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
207 if( !(ents->Proc.CPUFlags & 1) ) {
212 // Check if there is too many processors
213 if(giNumCPUs >= MAX_CPUS) {
214 giNumCPUs ++; // If `giNumCPUs` > MAX_CPUS later, it will be clipped
218 // Initialise CPU Info
219 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
220 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
221 gaCPUs[giNumCPUs].State = 0;
225 if( ents->Proc.CPUFlags & 2 ) {
226 giProc_BootProcessorID = giNumCPUs-1;
233 Log("\t.ID = %i", ents->Bus.ID);
234 Log("\t.TypeString = '%6C'", ents->Bus.TypeString);
238 Log("%i: I/O APIC", i);
239 Log("\t.ID = %i", ents->IOAPIC.ID);
240 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
241 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
242 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
244 case 3: // I/O Interrupt Assignment
246 Log("%i: I/O Interrupt Assignment", i);
247 Log("\t.IntType = %i", ents->IOInt.IntType);
248 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
249 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
250 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
251 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
252 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
254 case 4: // Local Interrupt Assignment
256 Log("%i: Local Interrupt Assignment", i);
257 Log("\t.IntType = %i", ents->LocalInt.IntType);
258 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
259 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
260 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
261 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
262 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
265 Log("%i: Unknown (%i)", i, ents->Type);
268 ents = (void*)( (Uint)ents + entSize );
271 if( giNumCPUs > MAX_CPUS ) {
272 Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
273 giNumCPUs = MAX_CPUS;
278 Log("No MP Table was found, assuming uniprocessor\n");
285 MM_FinishVirtualInit();
288 // Initialise Double Fault TSS
289 gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
290 gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
291 gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
293 // Set double fault IDT to use the new TSS
294 gIDT[8].OffsetLo = 0;
296 gIDT[8].Flags = 0x8500;
297 gIDT[8].OffsetHi = 0;
300 // Initialise Normal TSS(s)
301 for(pos=0;pos<giNumCPUs;pos++)
306 gTSSs[pos].SS0 = 0x10;
307 gTSSs[pos].ESP0 = 0; // Set properly by scheduler
308 gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
309 gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
310 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
315 for( pos = 0; pos < giNumCPUs; pos ++ )
317 gaCPUs[pos].Current = NULL;
318 if( pos != giProc_BootProcessorID ) {
319 Log("Starting AP %i, (APIC %i)\n", pos, gaCPUs[pos].APICID);
324 Log("Waiting for APs to come up\n");
325 while( giNumInitingCPUs ) __asm__ __volatile__ ("hlt");
326 MM_FinishVirtualInit();
327 //Panic("Uh oh... MP Table Parsing is unimplemented\n");
330 // Load the BSP's TSS
331 __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
334 gaCPUs[0].Current = &gThreadZero;
336 gCurrentThread = &gThreadZero;
340 gThreadZero.MemState.PDP[0] = 0;
341 gThreadZero.MemState.PDP[1] = 0;
342 gThreadZero.MemState.PDP[2] = 0;
344 gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
347 // Set timer frequency
348 outb(0x43, 0x34); // Set Channel 0, Low/High, Rate Generator
349 outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
350 outb(0x40, (TIMER_DIVISOR>>8)&0xFF); // High Byte
352 // Create Per-Process Data Block
353 MM_Allocate(MM_PPD_CFG);
360 void MP_StartAP(int CPU)
362 Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
364 // Set location of AP startup code and mark for a warm restart
365 *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
366 *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
367 outb(0x70, 0x0F); outb(0x71, 0x0A); // Warm Reset
368 MP_SendIPI(gaCPUs[CPU].APICID, 0, 5); // Init IPI
371 inb(0x80); inb(0x80); inb(0x80); inb(0x80);
374 *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA; // Far JMP
375 *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0); // IP
376 *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF; // CS
377 // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
379 MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6); // StartupIPI
385 * \brief Send an Inter-Processor Interrupt
386 * \param APICID Processor's Local APIC ID
387 * \param Vector Argument of some kind
388 * \param DeliveryMode Type of signal?
390 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
392 Uint32 addr = (Uint)gpMP_LocalAPIC + 0x300;
396 val = (Uint)APICID << 24;
397 Log("*%p = 0x%08x", addr+0x10, val);
398 *(Uint32*)(addr+0x10) = val;
401 val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
402 Log("*%p = 0x%08x", addr, val);
403 *(Uint32*)addr = val;
408 * \fn void Proc_Start(void)
409 * \brief Start process scheduler
411 void Proc_Start(void)
413 // Start Interrupts (and hence scheduler)
414 __asm__ __volatile__("sti");
418 * \fn tThread *Proc_GetCurThread(void)
419 * \brief Gets the current thread
421 tThread *Proc_GetCurThread(void)
424 //return gaCPUs[ gaAPIC_to_CPU[gpMP_LocalAPIC->ID.Val&0xFF] ].Current;
425 return gaCPUs[ GetCPUNum() ].Current;
427 return gCurrentThread;
432 * \fn void Proc_ChangeStack(void)
433 * \brief Swaps the current stack for a new one (in the proper stack reigon)
435 void Proc_ChangeStack(void)
439 Uint curBase, newBase;
441 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
442 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
447 newBase = MM_NewKStack();
450 Panic("What the?? Unable to allocate space for initial kernel stack");
454 curBase = (Uint)&Kernel_Stack_Top;
456 LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
458 // Get ESP as a used size
460 LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
462 memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
463 // Get ESP as an offset in the new stack
466 ebp = newBase - (curBase - ebp);
468 // Repair EBPs & Stack Addresses
469 // Catches arguments also, but may trash stack-address-like values
470 for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
472 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
473 *(Uint*)tmpEbp += newBase - curBase;
476 Proc_GetCurThread()->KernelStack = newBase;
478 __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
479 __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
483 * \fn int Proc_Clone(Uint *Err, Uint Flags)
484 * \brief Clone the current process
486 int Proc_Clone(Uint *Err, Uint Flags)
489 tThread *cur = Proc_GetCurThread();
492 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
493 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
495 newThread = Threads_CloneTCB(Err, Flags);
496 if(!newThread) return -1;
498 // Initialise Memory Space (New Addr space or kernel stack)
499 if(Flags & CLONE_VM) {
500 newThread->MemState.CR3 = MM_Clone();
501 newThread->KernelStack = cur->KernelStack;
503 Uint tmpEbp, oldEsp = esp;
506 newThread->MemState.CR3 = cur->MemState.CR3;
509 newThread->KernelStack = MM_NewKStack();
511 if(newThread->KernelStack == 0) {
516 // Get ESP as a used size
517 esp = cur->KernelStack - esp;
519 memcpy( (void*)(newThread->KernelStack - esp), (void*)(cur->KernelStack - esp), esp );
520 // Get ESP as an offset in the new stack
521 esp = newThread->KernelStack - esp;
523 ebp = newThread->KernelStack - (cur->KernelStack - ebp);
525 // Repair EBPs & Stack Addresses
526 // Catches arguments also, but may trash stack-address-like values
527 for(tmpEbp = esp; tmpEbp < newThread->KernelStack; tmpEbp += 4)
529 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < cur->KernelStack)
530 *(Uint*)tmpEbp += newThread->KernelStack - cur->KernelStack;
534 // Save core machine state
535 newThread->SavedState.ESP = esp;
536 newThread->SavedState.EBP = ebp;
538 if(eip == SWITCH_MAGIC) {
539 outb(0x20, 0x20); // ACK Timer and return as child
544 newThread->SavedState.EIP = eip;
546 // Lock list and add to active
547 Threads_AddActive(newThread);
549 return newThread->TID;
553 * \fn int Proc_SpawnWorker(void)
554 * \brief Spawns a new worker thread
556 int Proc_SpawnWorker(void)
561 cur = Proc_GetCurThread();
564 new = malloc( sizeof(tThread) );
566 Warning("Proc_SpawnWorker - Out of heap space!\n");
569 memcpy(new, &gThreadZero, sizeof(tThread));
571 new->TID = giNextTID++;
572 // Create a new worker stack (in PID0's address space)
573 // The stack is relocated by this code
574 new->KernelStack = MM_NewWorkerStack();
576 // Get ESP and EBP based in the new stack
577 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
578 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
579 esp = new->KernelStack - (cur->KernelStack - esp);
580 ebp = new->KernelStack - (cur->KernelStack - ebp);
582 // Save core machine state
583 new->SavedState.ESP = esp;
584 new->SavedState.EBP = ebp;
586 if(eip == SWITCH_MAGIC) {
587 outb(0x20, 0x20); // ACK Timer and return as child
592 new->SavedState.EIP = eip;
594 new->Status = THREAD_STAT_ACTIVE;
595 Threads_AddActive( new );
601 * \fn Uint Proc_MakeUserStack(void)
602 * \brief Creates a new user stack
604 Uint Proc_MakeUserStack(void)
607 Uint base = USER_STACK_TOP - USER_STACK_SZ;
609 // Check Prospective Space
610 for( i = USER_STACK_SZ >> 12; i--; )
611 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
614 if(i != -1) return 0;
616 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
617 for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
618 MM_Allocate( base + (i<<12) );
620 return base + USER_STACK_SZ;
624 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
625 * \brief Starts a user task
627 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
629 Uint *stack = (void*)Proc_MakeUserStack();
634 //Log("stack = %p", stack);
637 stack -= DataSize/sizeof(*stack);
638 memcpy( stack, ArgV, DataSize );
640 //Log("stack = %p", stack);
644 // Adjust Arguments and environment
645 delta = (Uint)stack - (Uint)ArgV;
646 ArgV = (char**)stack;
647 for( i = 0; ArgV[i]; i++ )
651 // Do we care about EnvP?
654 for( i = 0; EnvP[i]; i++ )
659 // User Mode Segments
660 ss = 0x23; cs = 0x1B;
663 *--stack = (Uint)EnvP;
664 *--stack = (Uint)ArgV;
665 *--stack = (Uint)ArgC;
668 *--stack = 0; // Return Address
670 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
673 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
675 Uint *stack = (void*)Stack;
676 *--stack = SS; //Stack Segment
677 *--stack = Stack; //Stack Pointer
678 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
679 *--stack = CS; //Code Segment
682 *--stack = 0xAAAAAAAA; // eax
683 *--stack = 0xCCCCCCCC; // ecx
684 *--stack = 0xDDDDDDDD; // edx
685 *--stack = 0xBBBBBBBB; // ebx
686 *--stack = 0xD1D1D1D1; // edi
687 *--stack = 0x54545454; // esp - NOT POPED
688 *--stack = 0x51515151; // esi
689 *--stack = 0xB4B4B4B4; // ebp
696 __asm__ __volatile__ (
697 "mov %%eax,%%esp;\n\t" // Set stack pointer
703 "iret;\n\t" : : "a" (stack));
708 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
709 * \brief Demotes a process to a lower permission level
710 * \param Err Pointer to user's errno
711 * \param Dest New Permission Level
712 * \param Regs Pointer to user's register structure
714 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
716 int cpl = Regs->cs & 3;
718 if(Dest > 3 || Dest < 0) {
729 // Change the Segment Registers
730 Regs->cs = (((Dest+1)<<4) | Dest) - 8;
731 Regs->ss = ((Dest+1)<<4) | Dest;
732 // Check if the GP Segs are GDT, then change them
733 if(!(Regs->ds & 4)) Regs->ds = ((Dest+1)<<4) | Dest;
734 if(!(Regs->es & 4)) Regs->es = ((Dest+1)<<4) | Dest;
735 if(!(Regs->fs & 4)) Regs->fs = ((Dest+1)<<4) | Dest;
736 if(!(Regs->gs & 4)) Regs->gs = ((Dest+1)<<4) | Dest;
742 * \brief Calls a signal handler in user mode
743 * \note Used for signals
745 void Proc_CallFaultHandler(tThread *Thread)
747 // Rewinds the stack and calls the user function
749 __asm__ __volatile__ ("mov %0, %%ebp;\n\tcall Proc_ReturnToUser" :: "r"(Thread->FaultHandler));
754 * \fn void Proc_Scheduler(int CPU)
755 * \brief Swap current thread and clears dead threads
757 void Proc_Scheduler(int CPU)
762 // If the spinlock is set, let it complete
763 if(IS_LOCKED(&glThreadListLock)) return;
765 // Clear Delete Queue
766 while(gDeleteThreads)
768 thread = gDeleteThreads->Next;
769 if(gDeleteThreads->IsLocked) { // Only free if structure is unused
770 gDeleteThreads->Status = THREAD_STAT_NULL;
771 free( gDeleteThreads );
773 gDeleteThreads = thread;
776 // Check if there is any tasks running
777 if(giNumActiveThreads == 0) {
778 Log("No Active threads, sleeping");
779 __asm__ __volatile__ ("hlt");
783 // Get current thread
785 thread = gaCPUs[CPU].Current;
787 thread = gCurrentThread;
790 // Reduce remaining quantum and continue timeslice if non-zero
791 if(thread->Remaining--) return;
792 // Reset quantum for next call
793 thread->Remaining = thread->Quantum;
796 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
797 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
799 if(eip == SWITCH_MAGIC) return; // Check if a switch happened
801 // Save machine state
802 thread->SavedState.ESP = esp;
803 thread->SavedState.EBP = ebp;
804 thread->SavedState.EIP = eip;
807 thread = Threads_GetNextToRun(CPU);
811 Warning("Hmm... Threads_GetNextToRun returned NULL, I don't think this should happen.\n");
815 #if DEBUG_TRACE_SWITCH
816 Log("Switching to task %i, CR3 = 0x%x, EIP = %p",
818 thread->MemState.CR3,
819 thread->SavedState.EIP
823 // Set current thread
825 gaCPUs[CPU].Current = thread;
827 gCurrentThread = thread;
830 //Log("CPU = %i", CPU);
832 // Update Kernel Stack pointer
833 gTSSs[CPU].ESP0 = thread->KernelStack-4;
837 # error "Todo: Implement PAE Address space switching"
839 __asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
843 if(thread->SavedState.ESP > 0xC0000000
844 && thread->SavedState.ESP < thread->KernelStack-0x2000) {
845 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
850 __asm__ __volatile__ (
851 "mov %1, %%esp\n\t" // Restore ESP
852 "mov %2, %%ebp\n\t" // and EBP
853 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
854 "a"(SWITCH_MAGIC), "b"(thread->SavedState.ESP),
855 "d"(thread->SavedState.EBP), "c"(thread->SavedState.EIP)
857 for(;;); // Shouldn't reach here
861 EXPORT(Proc_SpawnWorker);