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 Uint32 giMP_TimerCount; // Start Count for Local APIC Timer
77 tAPIC *gpMP_LocalAPIC = NULL;
78 Uint8 gaAPIC_to_CPU[256] = {0};
79 tCPU gaCPUs[MAX_CPUS];
80 tTSS gaTSSs[MAX_CPUS]; // TSS Array
81 int giProc_BootProcessorID = 0;
83 tThread *gCurrentThread = NULL;
86 Uint32 *gPML4s[4] = NULL;
88 tTSS *gTSSs = NULL; // Pointer to TSS array
90 // --- Error Recovery ---
91 char gaDoubleFaultStack[1024];
92 tTSS gDoubleFault_TSS = {
93 .ESP0 = (Uint)&gaDoubleFaultStack[1023],
95 .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
97 .ESP = (Uint)&gaDoubleFaultStack[1023],
98 .CS = 0x08, .SS = 0x10,
99 .DS = 0x10, .ES = 0x10,
100 .FS = 0x10, .GS = 0x10,
105 * \fn void ArchThreads_Init(void)
106 * \brief Starts the process scheduler
108 void ArchThreads_Init(void)
115 // Mark BSP as active
118 // -- Initialise Multiprocessing
119 // Find MP Floating Table
120 // - EBDA/Last 1Kib (640KiB)
121 for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
122 if( *(Uint*)(pos) == MPPTR_IDENT ) {
123 Log("Possible %p", pos);
124 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
125 gMPFloatPtr = (void*)pos;
129 // - Last KiB (512KiB base mem)
131 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
132 if( *(Uint*)(pos) == MPPTR_IDENT ) {
133 Log("Possible %p", pos);
134 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
135 gMPFloatPtr = (void*)pos;
142 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
143 if( *(Uint*)(pos) == MPPTR_IDENT ) {
144 Log("Possible %p", pos);
145 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
146 gMPFloatPtr = (void*)pos;
152 // If the MP Table Exists, parse it
157 Log("gMPFloatPtr = %p", gMPFloatPtr);
158 Log("*gMPFloatPtr = {");
159 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
160 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
161 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
162 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
163 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
164 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
165 gMPFloatPtr->Features[0], gMPFloatPtr->Features[1],
166 gMPFloatPtr->Features[2], gMPFloatPtr->Features[3],
167 gMPFloatPtr->Features[4]
171 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
172 Log("mptable = %p", mptable);
174 Log("\t.Sig = 0x%08x", mptable->Sig);
175 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
176 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
177 Log("\t.Checksum = 0x%02x", mptable->Checksum);
178 Log("\t.OEMID = '%8c'", mptable->OemID);
179 Log("\t.ProductID = '%8c'", mptable->ProductID);
180 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
181 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
182 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
183 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
184 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
185 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
188 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
190 ents = mptable->Entries;
193 for( i = 0; i < mptable->EntryCount; i ++ )
200 Log("%i: Processor", i);
201 Log("\t.APICID = %i", ents->Proc.APICID);
202 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
203 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
204 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
205 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
208 if( !(ents->Proc.CPUFlags & 1) ) {
213 // Check if there is too many processors
214 if(giNumCPUs >= MAX_CPUS) {
215 giNumCPUs ++; // If `giNumCPUs` > MAX_CPUS later, it will be clipped
219 // Initialise CPU Info
220 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
221 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
222 gaCPUs[giNumCPUs].State = 0;
226 if( ents->Proc.CPUFlags & 2 ) {
227 giProc_BootProcessorID = giNumCPUs-1;
234 Log("\t.ID = %i", ents->Bus.ID);
235 Log("\t.TypeString = '%6C'", ents->Bus.TypeString);
239 Log("%i: I/O APIC", i);
240 Log("\t.ID = %i", ents->IOAPIC.ID);
241 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
242 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
243 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
245 case 3: // I/O Interrupt Assignment
247 Log("%i: I/O Interrupt Assignment", i);
248 Log("\t.IntType = %i", ents->IOInt.IntType);
249 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
250 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
251 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
252 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
253 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
255 case 4: // Local Interrupt Assignment
257 Log("%i: Local Interrupt Assignment", i);
258 Log("\t.IntType = %i", ents->LocalInt.IntType);
259 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
260 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
261 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
262 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
263 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
266 Log("%i: Unknown (%i)", i, ents->Type);
269 ents = (void*)( (Uint)ents + entSize );
272 if( giNumCPUs > MAX_CPUS ) {
273 Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
274 giNumCPUs = MAX_CPUS;
279 Log("No MP Table was found, assuming uniprocessor\n");
286 MM_FinishVirtualInit();
289 // Initialise Double Fault TSS
290 gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
291 gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
292 gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
294 // Set double fault IDT to use the new TSS
295 gIDT[8].OffsetLo = 0;
297 gIDT[8].Flags = 0x8500;
298 gIDT[8].OffsetHi = 0;
300 // Set timer frequency
301 outb(0x43, 0x34); // Set Channel 0, Low/High, Rate Generator
302 outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
303 outb(0x40, (TIMER_DIVISOR>>8)&0xFF); // High Byte
304 // Get the count setting for APIC timer
305 Log("Determining APIC Count");
306 __asm__ __volatile__ ("sti");
307 while( giMP_TimerCount == 0 ) __asm__ __volatile__ ("hlt");
308 __asm__ __volatile__ ("cli");
309 Log("APIC Count %i\n", giMP_TimerCount);
312 // Initialise Normal TSS(s)
313 for(pos=0;pos<giNumCPUs;pos++)
318 gTSSs[pos].SS0 = 0x10;
319 gTSSs[pos].ESP0 = 0; // Set properly by scheduler
320 gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
321 gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
322 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
327 for( pos = 0; pos < giNumCPUs; pos ++ )
329 gaCPUs[pos].Current = NULL;
330 if( pos != giProc_BootProcessorID ) {
335 Log("Waiting for APs to come up\n");
336 while( giNumInitingCPUs ) __asm__ __volatile__ ("hlt");
337 MM_FinishVirtualInit();
338 //Panic("Uh oh... MP Table Parsing is unimplemented\n");
341 // Load the BSP's TSS
342 __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
345 gaCPUs[0].Current = &gThreadZero;
347 gCurrentThread = &gThreadZero;
351 gThreadZero.MemState.PDP[0] = 0;
352 gThreadZero.MemState.PDP[1] = 0;
353 gThreadZero.MemState.PDP[2] = 0;
355 gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
358 // Create Per-Process Data Block
359 MM_Allocate(MM_PPD_CFG);
366 void MP_StartAP(int CPU)
368 Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
370 // Set location of AP startup code and mark for a warm restart
371 *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
372 *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
373 outb(0x70, 0x0F); outb(0x71, 0x0A); // Warm Reset
374 MP_SendIPI(gaCPUs[CPU].APICID, 0, 5); // Init IPI
377 inb(0x80); inb(0x80); inb(0x80); inb(0x80);
379 // TODO: Use a better address, preferably registered with the MM
380 // - MM_AllocDMA mabye?
382 *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA; // Far JMP
383 *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0); // IP
384 *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF; // CS
385 // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
387 MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6); // StartupIPI
393 * \brief Send an Inter-Processor Interrupt
394 * \param APICID Processor's Local APIC ID
395 * \param Vector Argument of some kind
396 * \param DeliveryMode Type of signal?
398 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
403 val = (Uint)APICID << 24;
404 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
405 gpMP_LocalAPIC->ICR[1].Val = val;
407 val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
408 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
409 gpMP_LocalAPIC->ICR[0].Val = val;
414 * \fn void Proc_Start(void)
415 * \brief Start process scheduler
417 void Proc_Start(void)
419 // Start Interrupts (and hence scheduler)
420 __asm__ __volatile__("sti");
424 * \fn tThread *Proc_GetCurThread(void)
425 * \brief Gets the current thread
427 tThread *Proc_GetCurThread(void)
430 //return gaCPUs[ gaAPIC_to_CPU[gpMP_LocalAPIC->ID.Val&0xFF] ].Current;
431 return gaCPUs[ GetCPUNum() ].Current;
433 return gCurrentThread;
438 * \fn void Proc_ChangeStack(void)
439 * \brief Swaps the current stack for a new one (in the proper stack reigon)
441 void Proc_ChangeStack(void)
445 Uint curBase, newBase;
447 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
448 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
453 newBase = MM_NewKStack();
456 Panic("What the?? Unable to allocate space for initial kernel stack");
460 curBase = (Uint)&Kernel_Stack_Top;
462 LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
464 // Get ESP as a used size
466 LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
468 memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
469 // Get ESP as an offset in the new stack
472 ebp = newBase - (curBase - ebp);
474 // Repair EBPs & Stack Addresses
475 // Catches arguments also, but may trash stack-address-like values
476 for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
478 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
479 *(Uint*)tmpEbp += newBase - curBase;
482 Proc_GetCurThread()->KernelStack = newBase;
484 __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
485 __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
489 * \fn int Proc_Clone(Uint *Err, Uint Flags)
490 * \brief Clone the current process
492 int Proc_Clone(Uint *Err, Uint Flags)
495 tThread *cur = Proc_GetCurThread();
498 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
499 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
501 newThread = Threads_CloneTCB(Err, Flags);
502 if(!newThread) return -1;
504 // Initialise Memory Space (New Addr space or kernel stack)
505 if(Flags & CLONE_VM) {
506 newThread->MemState.CR3 = MM_Clone();
507 newThread->KernelStack = cur->KernelStack;
509 Uint tmpEbp, oldEsp = esp;
512 newThread->MemState.CR3 = cur->MemState.CR3;
515 newThread->KernelStack = MM_NewKStack();
517 if(newThread->KernelStack == 0) {
522 // Get ESP as a used size
523 esp = cur->KernelStack - esp;
525 memcpy( (void*)(newThread->KernelStack - esp), (void*)(cur->KernelStack - esp), esp );
526 // Get ESP as an offset in the new stack
527 esp = newThread->KernelStack - esp;
529 ebp = newThread->KernelStack - (cur->KernelStack - ebp);
531 // Repair EBPs & Stack Addresses
532 // Catches arguments also, but may trash stack-address-like values
533 for(tmpEbp = esp; tmpEbp < newThread->KernelStack; tmpEbp += 4)
535 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < cur->KernelStack)
536 *(Uint*)tmpEbp += newThread->KernelStack - cur->KernelStack;
540 // Save core machine state
541 newThread->SavedState.ESP = esp;
542 newThread->SavedState.EBP = ebp;
544 if(eip == SWITCH_MAGIC) {
545 outb(0x20, 0x20); // ACK Timer and return as child
550 newThread->SavedState.EIP = eip;
552 // Lock list and add to active
553 Threads_AddActive(newThread);
555 return newThread->TID;
559 * \fn int Proc_SpawnWorker(void)
560 * \brief Spawns a new worker thread
562 int Proc_SpawnWorker(void)
567 cur = Proc_GetCurThread();
570 new = malloc( sizeof(tThread) );
572 Warning("Proc_SpawnWorker - Out of heap space!\n");
575 memcpy(new, &gThreadZero, sizeof(tThread));
577 new->TID = giNextTID++;
578 // Create a new worker stack (in PID0's address space)
579 // The stack is relocated by this code
580 new->KernelStack = MM_NewWorkerStack();
582 // Get ESP and EBP based in the new stack
583 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
584 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
585 esp = new->KernelStack - (cur->KernelStack - esp);
586 ebp = new->KernelStack - (cur->KernelStack - ebp);
588 // Save core machine state
589 new->SavedState.ESP = esp;
590 new->SavedState.EBP = ebp;
592 if(eip == SWITCH_MAGIC) {
593 outb(0x20, 0x20); // ACK Timer and return as child
598 new->SavedState.EIP = eip;
600 new->Status = THREAD_STAT_ACTIVE;
601 Threads_AddActive( new );
607 * \fn Uint Proc_MakeUserStack(void)
608 * \brief Creates a new user stack
610 Uint Proc_MakeUserStack(void)
613 Uint base = USER_STACK_TOP - USER_STACK_SZ;
615 // Check Prospective Space
616 for( i = USER_STACK_SZ >> 12; i--; )
617 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
620 if(i != -1) return 0;
622 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
623 for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
624 MM_Allocate( base + (i<<12) );
626 return base + USER_STACK_SZ;
630 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
631 * \brief Starts a user task
633 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
635 Uint *stack = (void*)Proc_MakeUserStack();
640 //Log("stack = %p", stack);
643 stack -= DataSize/sizeof(*stack);
644 memcpy( stack, ArgV, DataSize );
646 //Log("stack = %p", stack);
650 // Adjust Arguments and environment
651 delta = (Uint)stack - (Uint)ArgV;
652 ArgV = (char**)stack;
653 for( i = 0; ArgV[i]; i++ )
657 // Do we care about EnvP?
660 for( i = 0; EnvP[i]; i++ )
665 // User Mode Segments
666 ss = 0x23; cs = 0x1B;
669 *--stack = (Uint)EnvP;
670 *--stack = (Uint)ArgV;
671 *--stack = (Uint)ArgC;
674 *--stack = 0; // Return Address
676 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
679 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
681 Uint *stack = (void*)Stack;
682 *--stack = SS; //Stack Segment
683 *--stack = Stack; //Stack Pointer
684 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
685 *--stack = CS; //Code Segment
688 *--stack = 0xAAAAAAAA; // eax
689 *--stack = 0xCCCCCCCC; // ecx
690 *--stack = 0xDDDDDDDD; // edx
691 *--stack = 0xBBBBBBBB; // ebx
692 *--stack = 0xD1D1D1D1; // edi
693 *--stack = 0x54545454; // esp - NOT POPED
694 *--stack = 0x51515151; // esi
695 *--stack = 0xB4B4B4B4; // ebp
702 __asm__ __volatile__ (
703 "mov %%eax,%%esp;\n\t" // Set stack pointer
709 "iret;\n\t" : : "a" (stack));
714 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
715 * \brief Demotes a process to a lower permission level
716 * \param Err Pointer to user's errno
717 * \param Dest New Permission Level
718 * \param Regs Pointer to user's register structure
720 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
722 int cpl = Regs->cs & 3;
724 if(Dest > 3 || Dest < 0) {
735 // Change the Segment Registers
736 Regs->cs = (((Dest+1)<<4) | Dest) - 8;
737 Regs->ss = ((Dest+1)<<4) | Dest;
738 // Check if the GP Segs are GDT, then change them
739 if(!(Regs->ds & 4)) Regs->ds = ((Dest+1)<<4) | Dest;
740 if(!(Regs->es & 4)) Regs->es = ((Dest+1)<<4) | Dest;
741 if(!(Regs->fs & 4)) Regs->fs = ((Dest+1)<<4) | Dest;
742 if(!(Regs->gs & 4)) Regs->gs = ((Dest+1)<<4) | Dest;
748 * \brief Calls a signal handler in user mode
749 * \note Used for signals
751 void Proc_CallFaultHandler(tThread *Thread)
753 // Rewinds the stack and calls the user function
755 __asm__ __volatile__ ("mov %0, %%ebp;\n\tcall Proc_ReturnToUser" :: "r"(Thread->FaultHandler));
760 * \fn void Proc_Scheduler(int CPU)
761 * \brief Swap current thread and clears dead threads
763 void Proc_Scheduler(int CPU)
768 // If the spinlock is set, let it complete
769 if(IS_LOCKED(&glThreadListLock)) return;
771 // Clear Delete Queue
772 while(gDeleteThreads)
774 thread = gDeleteThreads->Next;
775 if(gDeleteThreads->IsLocked) { // Only free if structure is unused
776 gDeleteThreads->Status = THREAD_STAT_NULL;
777 free( gDeleteThreads );
779 gDeleteThreads = thread;
782 // Check if there is any tasks running
783 if(giNumActiveThreads == 0) {
784 Log("No Active threads, sleeping");
785 __asm__ __volatile__ ("hlt");
789 // Get current thread
791 thread = gaCPUs[CPU].Current;
793 thread = gCurrentThread;
796 // Reduce remaining quantum and continue timeslice if non-zero
797 if(thread->Remaining--) return;
798 // Reset quantum for next call
799 thread->Remaining = thread->Quantum;
802 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
803 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
805 if(eip == SWITCH_MAGIC) return; // Check if a switch happened
807 // Save machine state
808 thread->SavedState.ESP = esp;
809 thread->SavedState.EBP = ebp;
810 thread->SavedState.EIP = eip;
813 thread = Threads_GetNextToRun(CPU);
817 Warning("Hmm... Threads_GetNextToRun returned NULL, I don't think this should happen.\n");
821 #if DEBUG_TRACE_SWITCH
822 Log("Switching to task %i, CR3 = 0x%x, EIP = %p",
824 thread->MemState.CR3,
825 thread->SavedState.EIP
829 // Set current thread
831 gaCPUs[CPU].Current = thread;
833 gCurrentThread = thread;
836 //Log("CPU = %i", CPU);
838 // Update Kernel Stack pointer
839 gTSSs[CPU].ESP0 = thread->KernelStack-4;
843 # error "Todo: Implement PAE Address space switching"
845 __asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
849 if(thread->SavedState.ESP > 0xC0000000
850 && thread->SavedState.ESP < thread->KernelStack-0x2000) {
851 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
856 __asm__ __volatile__ (
857 "mov %1, %%esp\n\t" // Restore ESP
858 "mov %2, %%ebp\n\t" // and EBP
859 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
860 "a"(SWITCH_MAGIC), "b"(thread->SavedState.ESP),
861 "d"(thread->SavedState.EBP), "c"(thread->SavedState.EIP)
863 for(;;); // Shouldn't reach here
867 EXPORT(Proc_SpawnWorker);