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_BASE 1193182
21 #define TIMER_DIVISOR 11931 //~100Hz
28 Uint8 State; // 0: Unavaliable, 1: Idle, 2: Active
37 extern void APWait(void); // 16-bit AP pause code
38 extern void APStartup(void); // 16-bit AP startup code
39 extern Uint GetEIP(void); // start.asm
40 extern int GetCPUNum(void); // start.asm
41 extern Uint32 gaInitPageDir[1024]; // start.asm
42 extern void Kernel_Stack_Top;
43 extern tSpinlock glThreadListLock;
46 extern int giTotalTickets;
47 extern int giNumActiveThreads;
48 extern tThread gThreadZero;
49 extern tThread *gActiveThreads;
50 extern tThread *gSleepingThreads;
51 extern tThread *gDeleteThreads;
52 extern tThread *Threads_GetNextToRun(int CPU);
53 extern void Threads_Dump(void);
54 extern tThread *Threads_CloneTCB(Uint *Err, Uint Flags);
55 extern void Isr8(void); // Double Fault
56 extern void Proc_ReturnToUser(void);
59 void ArchThreads_Init(void);
61 void MP_StartAP(int CPU);
62 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
64 void Proc_Start(void);
65 tThread *Proc_GetCurThread(void);
66 void Proc_ChangeStack(void);
67 int Proc_Clone(Uint *Err, Uint Flags);
68 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP);
69 void Proc_CallFaultHandler(tThread *Thread);
70 void Proc_Scheduler(int CPU);
73 // --- Multiprocessing ---
75 volatile int giNumInitingCPUs = 0;
76 tMPInfo *gMPFloatPtr = NULL;
77 volatile Uint32 giMP_TimerCount; // Start Count for Local APIC Timer
78 tAPIC *gpMP_LocalAPIC = NULL;
79 Uint8 gaAPIC_to_CPU[256] = {0};
80 tCPU gaCPUs[MAX_CPUS];
81 tTSS gaTSSs[MAX_CPUS]; // TSS Array
82 int giProc_BootProcessorID = 0;
84 tThread *gCurrentThread = NULL;
87 Uint32 *gPML4s[4] = NULL;
89 tTSS *gTSSs = NULL; // Pointer to TSS array
91 // --- Error Recovery ---
92 char gaDoubleFaultStack[1024] __attribute__ ((section(".padata")));
93 tTSS gDoubleFault_TSS = {
94 .ESP0 = (Uint)&gaDoubleFaultStack[1024],
96 .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
98 .ESP = (Uint)&gaDoubleFaultStack[1024],
99 .CS = 0x08, .SS = 0x10,
100 .DS = 0x10, .ES = 0x10,
101 .FS = 0x10, .GS = 0x10,
106 * \fn void ArchThreads_Init(void)
107 * \brief Starts the process scheduler
109 void ArchThreads_Init(void)
116 // Mark BSP as active
119 // -- Initialise Multiprocessing
120 // Find MP Floating Table
121 // - EBDA/Last 1Kib (640KiB)
122 for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
123 if( *(Uint*)(pos) == MPPTR_IDENT ) {
124 Log("Possible %p", pos);
125 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
126 gMPFloatPtr = (void*)pos;
130 // - Last KiB (512KiB base mem)
132 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
133 if( *(Uint*)(pos) == MPPTR_IDENT ) {
134 Log("Possible %p", pos);
135 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
136 gMPFloatPtr = (void*)pos;
143 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
144 if( *(Uint*)(pos) == MPPTR_IDENT ) {
145 Log("Possible %p", pos);
146 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
147 gMPFloatPtr = (void*)pos;
153 // If the MP Table Exists, parse it
158 Log("gMPFloatPtr = %p", gMPFloatPtr);
159 Log("*gMPFloatPtr = {");
160 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
161 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
162 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
163 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
164 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
165 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
166 gMPFloatPtr->Features[0], gMPFloatPtr->Features[1],
167 gMPFloatPtr->Features[2], gMPFloatPtr->Features[3],
168 gMPFloatPtr->Features[4]
172 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
173 Log("mptable = %p", mptable);
175 Log("\t.Sig = 0x%08x", mptable->Sig);
176 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
177 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
178 Log("\t.Checksum = 0x%02x", mptable->Checksum);
179 Log("\t.OEMID = '%8c'", mptable->OemID);
180 Log("\t.ProductID = '%8c'", mptable->ProductID);
181 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
182 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
183 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
184 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
185 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
186 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
189 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
191 ents = mptable->Entries;
194 for( i = 0; i < mptable->EntryCount; i ++ )
201 Log("%i: Processor", i);
202 Log("\t.APICID = %i", ents->Proc.APICID);
203 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
204 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
205 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
206 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
209 if( !(ents->Proc.CPUFlags & 1) ) {
214 // Check if there is too many processors
215 if(giNumCPUs >= MAX_CPUS) {
216 giNumCPUs ++; // If `giNumCPUs` > MAX_CPUS later, it will be clipped
220 // Initialise CPU Info
221 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
222 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
223 gaCPUs[giNumCPUs].State = 0;
227 if( ents->Proc.CPUFlags & 2 ) {
228 giProc_BootProcessorID = giNumCPUs-1;
237 Log("\t.ID = %i", ents->Bus.ID);
238 Log("\t.TypeString = '%6C'", ents->Bus.TypeString);
242 Log("%i: I/O APIC", i);
243 Log("\t.ID = %i", ents->IOAPIC.ID);
244 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
245 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
246 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
248 case 3: // I/O Interrupt Assignment
250 Log("%i: I/O Interrupt Assignment", i);
251 Log("\t.IntType = %i", ents->IOInt.IntType);
252 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
253 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
254 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
255 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
256 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
258 case 4: // Local Interrupt Assignment
260 Log("%i: Local Interrupt Assignment", i);
261 Log("\t.IntType = %i", ents->LocalInt.IntType);
262 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
263 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
264 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
265 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
266 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
269 Log("%i: Unknown (%i)", i, ents->Type);
273 ents = (void*)( (Uint)ents + entSize );
276 if( giNumCPUs > MAX_CPUS ) {
277 Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
278 giNumCPUs = MAX_CPUS;
283 Log("No MP Table was found, assuming uniprocessor\n");
290 MM_FinishVirtualInit();
294 // Initialise Double Fault TSS
295 gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
296 gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
297 gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
299 // Set double fault IDT to use the new TSS
300 gIDT[8].OffsetLo = 0;
302 gIDT[8].Flags = 0x8500;
303 gIDT[8].OffsetHi = 0;
306 // Set timer frequency
307 outb(0x43, 0x34); // Set Channel 0, Low/High, Rate Generator
308 outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
309 outb(0x40, (TIMER_DIVISOR>>8)&0xFF); // High Byte
312 // Get the count setting for APIC timer
313 Log("Determining APIC Count");
314 __asm__ __volatile__ ("sti");
315 while( giMP_TimerCount == 0 ) __asm__ __volatile__ ("hlt");
316 __asm__ __volatile__ ("cli");
317 Log("APIC Count %i", giMP_TimerCount);
319 Uint64 freq = giMP_TimerCount;
320 freq /= TIMER_DIVISOR;
322 if( (freq /= 1000) < 2*1000)
323 Log("Bus Frequency %i KHz", freq);
324 else if( (freq /= 1000) < 2*1000)
325 Log("Bus Frequency %i MHz", freq);
326 else if( (freq /= 1000) < 2*1000)
327 Log("Bus Frequency %i GHz", freq);
329 Log("Bus Frequency %i THz", freq);
332 // Initialise Normal TSS(s)
333 for(pos=0;pos<giNumCPUs;pos++)
338 gTSSs[pos].SS0 = 0x10;
339 gTSSs[pos].ESP0 = 0; // Set properly by scheduler
340 gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
341 gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
342 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
347 for( pos = 0; pos < giNumCPUs; pos ++ )
349 gaCPUs[pos].Current = NULL;
350 if( pos != giProc_BootProcessorID ) {
355 Log("Waiting for APs to come up\n");
356 //__asm__ __volatile__ ("xchg %bx, %bx");
357 __asm__ __volatile__ ("sti");
358 while( giNumInitingCPUs ) __asm__ __volatile__ ("hlt");
359 __asm__ __volatile__ ("cli");
360 MM_FinishVirtualInit();
361 //Panic("Uh oh... MP Table Parsing is unimplemented\n");
364 // Load the BSP's TSS
365 __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
368 gaCPUs[0].Current = &gThreadZero;
370 gCurrentThread = &gThreadZero;
374 gThreadZero.MemState.PDP[0] = 0;
375 gThreadZero.MemState.PDP[1] = 0;
376 gThreadZero.MemState.PDP[2] = 0;
378 gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
381 // Create Per-Process Data Block
382 MM_Allocate(MM_PPD_CFG);
389 void MP_StartAP(int CPU)
391 Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
393 // Set location of AP startup code and mark for a warm restart
394 *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
395 *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
396 outb(0x70, 0x0F); outb(0x71, 0x0A); // Warm Reset
397 MP_SendIPI(gaCPUs[CPU].APICID, 0, 5); // Init IPI
400 inb(0x80); inb(0x80); inb(0x80); inb(0x80);
402 // TODO: Use a better address, preferably registered with the MM
403 // - MM_AllocDMA mabye?
405 *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA; // Far JMP
406 *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0); // IP
407 *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF; // CS
408 // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
410 MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6); // StartupIPI
416 * \brief Send an Inter-Processor Interrupt
417 * \param APICID Processor's Local APIC ID
418 * \param Vector Argument of some kind
419 * \param DeliveryMode Type of signal?
421 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
426 val = (Uint)APICID << 24;
427 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
428 gpMP_LocalAPIC->ICR[1].Val = val;
430 val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
431 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
432 gpMP_LocalAPIC->ICR[0].Val = val;
437 * \fn void Proc_Start(void)
438 * \brief Start process scheduler
440 void Proc_Start(void)
442 // Start Interrupts (and hence scheduler)
443 __asm__ __volatile__("sti");
447 * \fn tThread *Proc_GetCurThread(void)
448 * \brief Gets the current thread
450 tThread *Proc_GetCurThread(void)
453 //return gaCPUs[ gaAPIC_to_CPU[gpMP_LocalAPIC->ID.Val&0xFF] ].Current;
454 return gaCPUs[ GetCPUNum() ].Current;
456 return gCurrentThread;
461 * \fn void Proc_ChangeStack(void)
462 * \brief Swaps the current stack for a new one (in the proper stack reigon)
464 void Proc_ChangeStack(void)
468 Uint curBase, newBase;
470 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
471 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
476 newBase = MM_NewKStack();
479 Panic("What the?? Unable to allocate space for initial kernel stack");
483 curBase = (Uint)&Kernel_Stack_Top;
485 LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
487 // Get ESP as a used size
489 LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
491 memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
492 // Get ESP as an offset in the new stack
495 ebp = newBase - (curBase - ebp);
497 // Repair EBPs & Stack Addresses
498 // Catches arguments also, but may trash stack-address-like values
499 for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
501 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
502 *(Uint*)tmpEbp += newBase - curBase;
505 Proc_GetCurThread()->KernelStack = newBase;
507 __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
508 __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
512 * \fn int Proc_Clone(Uint *Err, Uint Flags)
513 * \brief Clone the current process
515 int Proc_Clone(Uint *Err, Uint Flags)
518 tThread *cur = Proc_GetCurThread();
521 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
522 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
524 newThread = Threads_CloneTCB(Err, Flags);
525 if(!newThread) return -1;
527 // Initialise Memory Space (New Addr space or kernel stack)
528 if(Flags & CLONE_VM) {
529 newThread->MemState.CR3 = MM_Clone();
530 newThread->KernelStack = cur->KernelStack;
532 Uint tmpEbp, oldEsp = esp;
535 newThread->MemState.CR3 = cur->MemState.CR3;
538 newThread->KernelStack = MM_NewKStack();
540 if(newThread->KernelStack == 0) {
545 // Get ESP as a used size
546 esp = cur->KernelStack - esp;
548 memcpy( (void*)(newThread->KernelStack - esp), (void*)(cur->KernelStack - esp), esp );
549 // Get ESP as an offset in the new stack
550 esp = newThread->KernelStack - esp;
552 ebp = newThread->KernelStack - (cur->KernelStack - ebp);
554 // Repair EBPs & Stack Addresses
555 // Catches arguments also, but may trash stack-address-like values
556 for(tmpEbp = esp; tmpEbp < newThread->KernelStack; tmpEbp += 4)
558 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < cur->KernelStack)
559 *(Uint*)tmpEbp += newThread->KernelStack - cur->KernelStack;
563 // Save core machine state
564 newThread->SavedState.ESP = esp;
565 newThread->SavedState.EBP = ebp;
567 if(eip == SWITCH_MAGIC) {
568 outb(0x20, 0x20); // ACK Timer and return as child
573 newThread->SavedState.EIP = eip;
575 // Lock list and add to active
576 Threads_AddActive(newThread);
578 return newThread->TID;
582 * \fn int Proc_SpawnWorker(void)
583 * \brief Spawns a new worker thread
585 int Proc_SpawnWorker(void)
590 cur = Proc_GetCurThread();
593 new = malloc( sizeof(tThread) );
595 Warning("Proc_SpawnWorker - Out of heap space!\n");
598 memcpy(new, &gThreadZero, sizeof(tThread));
600 new->TID = giNextTID++;
601 // Create a new worker stack (in PID0's address space)
602 // The stack is relocated by this code
603 new->KernelStack = MM_NewWorkerStack();
605 // Get ESP and EBP based in the new stack
606 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
607 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
608 esp = new->KernelStack - (cur->KernelStack - esp);
609 ebp = new->KernelStack - (cur->KernelStack - ebp);
611 // Save core machine state
612 new->SavedState.ESP = esp;
613 new->SavedState.EBP = ebp;
615 if(eip == SWITCH_MAGIC) {
616 outb(0x20, 0x20); // ACK Timer and return as child
621 new->SavedState.EIP = eip;
623 new->Status = THREAD_STAT_ACTIVE;
624 Threads_AddActive( new );
630 * \fn Uint Proc_MakeUserStack(void)
631 * \brief Creates a new user stack
633 Uint Proc_MakeUserStack(void)
636 Uint base = USER_STACK_TOP - USER_STACK_SZ;
638 // Check Prospective Space
639 for( i = USER_STACK_SZ >> 12; i--; )
640 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
643 if(i != -1) return 0;
645 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
646 for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
647 MM_Allocate( base + (i<<12) );
649 return base + USER_STACK_SZ;
653 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
654 * \brief Starts a user task
656 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
658 Uint *stack = (void*)Proc_MakeUserStack();
663 //Log("stack = %p", stack);
666 stack -= DataSize/sizeof(*stack);
667 memcpy( stack, ArgV, DataSize );
669 //Log("stack = %p", stack);
673 // Adjust Arguments and environment
674 delta = (Uint)stack - (Uint)ArgV;
675 ArgV = (char**)stack;
676 for( i = 0; ArgV[i]; i++ )
680 // Do we care about EnvP?
683 for( i = 0; EnvP[i]; i++ )
688 // User Mode Segments
689 ss = 0x23; cs = 0x1B;
692 *--stack = (Uint)EnvP;
693 *--stack = (Uint)ArgV;
694 *--stack = (Uint)ArgC;
697 *--stack = 0; // Return Address
699 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
702 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
704 Uint *stack = (void*)Stack;
705 *--stack = SS; //Stack Segment
706 *--stack = Stack; //Stack Pointer
707 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
708 *--stack = CS; //Code Segment
711 *--stack = 0xAAAAAAAA; // eax
712 *--stack = 0xCCCCCCCC; // ecx
713 *--stack = 0xDDDDDDDD; // edx
714 *--stack = 0xBBBBBBBB; // ebx
715 *--stack = 0xD1D1D1D1; // edi
716 *--stack = 0x54545454; // esp - NOT POPED
717 *--stack = 0x51515151; // esi
718 *--stack = 0xB4B4B4B4; // ebp
725 __asm__ __volatile__ (
726 "mov %%eax,%%esp;\n\t" // Set stack pointer
732 "iret;\n\t" : : "a" (stack));
737 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
738 * \brief Demotes a process to a lower permission level
739 * \param Err Pointer to user's errno
740 * \param Dest New Permission Level
741 * \param Regs Pointer to user's register structure
743 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
745 int cpl = Regs->cs & 3;
747 if(Dest > 3 || Dest < 0) {
758 // Change the Segment Registers
759 Regs->cs = (((Dest+1)<<4) | Dest) - 8;
760 Regs->ss = ((Dest+1)<<4) | Dest;
761 // Check if the GP Segs are GDT, then change them
762 if(!(Regs->ds & 4)) Regs->ds = ((Dest+1)<<4) | Dest;
763 if(!(Regs->es & 4)) Regs->es = ((Dest+1)<<4) | Dest;
764 if(!(Regs->fs & 4)) Regs->fs = ((Dest+1)<<4) | Dest;
765 if(!(Regs->gs & 4)) Regs->gs = ((Dest+1)<<4) | Dest;
771 * \brief Calls a signal handler in user mode
772 * \note Used for signals
774 void Proc_CallFaultHandler(tThread *Thread)
776 // Rewinds the stack and calls the user function
778 __asm__ __volatile__ ("mov %0, %%ebp;\n\tcall Proc_ReturnToUser" :: "r"(Thread->FaultHandler));
783 * \fn void Proc_Scheduler(int CPU)
784 * \brief Swap current thread and clears dead threads
786 void Proc_Scheduler(int CPU)
791 // If the spinlock is set, let it complete
792 if(IS_LOCKED(&glThreadListLock)) return;
794 // Clear Delete Queue
795 while(gDeleteThreads)
797 thread = gDeleteThreads->Next;
798 if(gDeleteThreads->IsLocked) { // Only free if structure is unused
799 gDeleteThreads->Status = THREAD_STAT_NULL;
800 free( gDeleteThreads );
802 gDeleteThreads = thread;
805 // Check if there is any tasks running
806 if(giNumActiveThreads == 0) {
807 Log("No Active threads, sleeping");
808 __asm__ __volatile__ ("hlt");
812 // Get current thread
814 thread = gaCPUs[CPU].Current;
816 thread = gCurrentThread;
819 // Reduce remaining quantum and continue timeslice if non-zero
820 if(thread->Remaining--) return;
821 // Reset quantum for next call
822 thread->Remaining = thread->Quantum;
825 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
826 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
828 if(eip == SWITCH_MAGIC) return; // Check if a switch happened
830 // Save machine state
831 thread->SavedState.ESP = esp;
832 thread->SavedState.EBP = ebp;
833 thread->SavedState.EIP = eip;
836 thread = Threads_GetNextToRun(CPU);
840 Warning("Hmm... Threads_GetNextToRun returned NULL, I don't think this should happen.\n");
844 #if DEBUG_TRACE_SWITCH
845 Log("Switching to task %i, CR3 = 0x%x, EIP = %p",
847 thread->MemState.CR3,
848 thread->SavedState.EIP
852 // Set current thread
854 gaCPUs[CPU].Current = thread;
856 gCurrentThread = thread;
859 //Log("CPU = %i", CPU);
861 // Update Kernel Stack pointer
862 gTSSs[CPU].ESP0 = thread->KernelStack-4;
866 # error "Todo: Implement PAE Address space switching"
868 __asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
872 if(thread->SavedState.ESP > 0xC0000000
873 && thread->SavedState.ESP < thread->KernelStack-0x2000) {
874 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
879 __asm__ __volatile__ (
880 "mov %1, %%esp\n\t" // Restore ESP
881 "mov %2, %%ebp\n\t" // and EBP
882 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
883 "a"(SWITCH_MAGIC), "b"(thread->SavedState.ESP),
884 "d"(thread->SavedState.EBP), "c"(thread->SavedState.EIP)
886 for(;;); // Shouldn't reach here
890 EXPORT(Proc_SpawnWorker);