2 * AcessOS Microkernel Version
16 #define DEBUG_TRACE_SWITCH 0
19 #define SWITCH_MAGIC 0xFFFACE55 // There is no code in this area
21 #define TIMER_BASE 1193182
22 #define TIMER_DIVISOR 11931 //~100Hz
29 Uint8 State; // 0: Unavaliable, 1: Idle, 2: Active
39 extern void APWait(void); // 16-bit AP pause code
40 extern void APStartup(void); // 16-bit AP startup code
41 extern Uint GetEIP(void); // start.asm
42 extern int GetCPUNum(void); // start.asm
43 extern Uint32 gaInitPageDir[1024]; // start.asm
44 extern void Kernel_Stack_Top;
45 extern tSpinlock glThreadListLock;
48 extern int giTotalTickets;
49 extern int giNumActiveThreads;
50 extern tThread gThreadZero;
51 extern tThread *gActiveThreads;
52 extern tThread *gSleepingThreads;
53 extern tThread *gDeleteThreads;
54 extern void Threads_Dump(void);
55 extern tThread *Threads_CloneTCB(Uint *Err, Uint Flags);
56 extern void Isr8(void); // Double Fault
57 extern void Proc_ReturnToUser(void);
60 void ArchThreads_Init(void);
62 void MP_StartAP(int CPU);
63 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
65 void Proc_Start(void);
66 tThread *Proc_GetCurThread(void);
67 void Proc_ChangeStack(void);
68 int Proc_Clone(Uint *Err, Uint Flags);
69 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP);
70 void Proc_CallFaultHandler(tThread *Thread);
71 void Proc_Scheduler(int CPU);
74 // --- Multiprocessing ---
76 volatile int giNumInitingCPUs = 0;
77 tMPInfo *gMPFloatPtr = NULL;
78 volatile Uint32 giMP_TimerCount; // Start Count for Local APIC Timer
79 tAPIC *gpMP_LocalAPIC = NULL;
80 Uint8 gaAPIC_to_CPU[256] = {0};
81 tCPU gaCPUs[MAX_CPUS];
82 tTSS gaTSSs[MAX_CPUS]; // TSS Array
83 int giProc_BootProcessorID = 0;
85 tThread *gCurrentThread = NULL;
86 tThread *gpIdleThread = NULL;
89 Uint32 *gPML4s[4] = NULL;
91 tTSS *gTSSs = NULL; // Pointer to TSS array
93 // --- Error Recovery ---
94 char gaDoubleFaultStack[1024] __attribute__ ((section(".padata")));
95 tTSS gDoubleFault_TSS = {
96 .ESP0 = (Uint)&gaDoubleFaultStack[1024],
98 .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
100 .ESP = (Uint)&gaDoubleFaultStack[1024],
101 .CS = 0x08, .SS = 0x10,
102 .DS = 0x10, .ES = 0x10,
103 .FS = 0x10, .GS = 0x10,
108 * \fn void ArchThreads_Init(void)
109 * \brief Starts the process scheduler
111 void ArchThreads_Init(void)
118 // Mark BSP as active
121 // -- Initialise Multiprocessing
122 // Find MP Floating Table
123 // - EBDA/Last 1Kib (640KiB)
124 for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
125 if( *(Uint*)(pos) == MPPTR_IDENT ) {
126 Log("Possible %p", pos);
127 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
128 gMPFloatPtr = (void*)pos;
132 // - Last KiB (512KiB base mem)
134 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
135 if( *(Uint*)(pos) == MPPTR_IDENT ) {
136 Log("Possible %p", pos);
137 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
138 gMPFloatPtr = (void*)pos;
145 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
146 if( *(Uint*)(pos) == MPPTR_IDENT ) {
147 Log("Possible %p", pos);
148 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
149 gMPFloatPtr = (void*)pos;
155 // If the MP Table Exists, parse it
160 Log("gMPFloatPtr = %p", gMPFloatPtr);
161 Log("*gMPFloatPtr = {");
162 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
163 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
164 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
165 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
166 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
167 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
168 gMPFloatPtr->Features[0], gMPFloatPtr->Features[1],
169 gMPFloatPtr->Features[2], gMPFloatPtr->Features[3],
170 gMPFloatPtr->Features[4]
174 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
175 Log("mptable = %p", mptable);
177 Log("\t.Sig = 0x%08x", mptable->Sig);
178 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
179 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
180 Log("\t.Checksum = 0x%02x", mptable->Checksum);
181 Log("\t.OEMID = '%8c'", mptable->OemID);
182 Log("\t.ProductID = '%8c'", mptable->ProductID);
183 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
184 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
185 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
186 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
187 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
188 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
191 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
193 ents = mptable->Entries;
196 for( i = 0; i < mptable->EntryCount; i ++ )
203 Log("%i: Processor", i);
204 Log("\t.APICID = %i", ents->Proc.APICID);
205 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
206 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
207 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
208 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
211 if( !(ents->Proc.CPUFlags & 1) ) {
216 // Check if there is too many processors
217 if(giNumCPUs >= MAX_CPUS) {
218 giNumCPUs ++; // If `giNumCPUs` > MAX_CPUS later, it will be clipped
222 // Initialise CPU Info
223 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
224 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
225 gaCPUs[giNumCPUs].State = 0;
229 if( ents->Proc.CPUFlags & 2 ) {
230 giProc_BootProcessorID = giNumCPUs-1;
239 Log("\t.ID = %i", ents->Bus.ID);
240 Log("\t.TypeString = '%6C'", ents->Bus.TypeString);
244 Log("%i: I/O APIC", i);
245 Log("\t.ID = %i", ents->IOAPIC.ID);
246 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
247 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
248 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
250 case 3: // I/O Interrupt Assignment
252 Log("%i: I/O Interrupt Assignment", i);
253 Log("\t.IntType = %i", ents->IOInt.IntType);
254 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
255 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
256 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
257 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
258 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
260 case 4: // Local Interrupt Assignment
262 Log("%i: Local Interrupt Assignment", i);
263 Log("\t.IntType = %i", ents->LocalInt.IntType);
264 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
265 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
266 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
267 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
268 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
271 Log("%i: Unknown (%i)", i, ents->Type);
275 ents = (void*)( (Uint)ents + entSize );
278 if( giNumCPUs > MAX_CPUS ) {
279 Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
280 giNumCPUs = MAX_CPUS;
285 Log("No MP Table was found, assuming uniprocessor\n");
292 MM_FinishVirtualInit();
296 // Initialise Double Fault TSS
297 gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
298 gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
299 gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
301 // Set double fault IDT to use the new TSS
302 gIDT[8].OffsetLo = 0;
304 gIDT[8].Flags = 0x8500;
305 gIDT[8].OffsetHi = 0;
308 // Set timer frequency
309 outb(0x43, 0x34); // Set Channel 0, Low/High, Rate Generator
310 outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
311 outb(0x40, (TIMER_DIVISOR>>8)&0xFF); // High Byte
314 // Get the count setting for APIC timer
315 Log("Determining APIC Count");
316 __asm__ __volatile__ ("sti");
317 while( giMP_TimerCount == 0 ) __asm__ __volatile__ ("hlt");
318 __asm__ __volatile__ ("cli");
319 Log("APIC Count %i", giMP_TimerCount);
321 Uint64 freq = giMP_TimerCount;
322 freq /= TIMER_DIVISOR;
324 if( (freq /= 1000) < 2*1000)
325 Log("Bus Frequency %i KHz", freq);
326 else if( (freq /= 1000) < 2*1000)
327 Log("Bus Frequency %i MHz", freq);
328 else if( (freq /= 1000) < 2*1000)
329 Log("Bus Frequency %i GHz", freq);
331 Log("Bus Frequency %i THz", freq);
334 // Initialise Normal TSS(s)
335 for(pos=0;pos<giNumCPUs;pos++)
340 gTSSs[pos].SS0 = 0x10;
341 gTSSs[pos].ESP0 = 0; // Set properly by scheduler
342 gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
343 gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
344 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
349 // Load the BSP's TSS
350 __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
353 gaCPUs[0].Current = &gThreadZero;
355 gCurrentThread = &gThreadZero;
357 gThreadZero.CurCPU = 0;
360 gThreadZero.MemState.PDP[0] = 0;
361 gThreadZero.MemState.PDP[1] = 0;
362 gThreadZero.MemState.PDP[2] = 0;
364 gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
367 // Create Per-Process Data Block
368 MM_Allocate(MM_PPD_CFG);
375 void MP_StartAP(int CPU)
377 Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
379 // Set location of AP startup code and mark for a warm restart
380 *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
381 *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
382 outb(0x70, 0x0F); outb(0x71, 0x0A); // Warm Reset
383 MP_SendIPI(gaCPUs[CPU].APICID, 0, 5); // Init IPI
386 inb(0x80); inb(0x80); inb(0x80); inb(0x80);
388 // TODO: Use a better address, preferably registered with the MM
389 // - MM_AllocDMA mabye?
391 *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA; // Far JMP
392 *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0); // IP
393 *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF; // CS
394 // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
396 MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6); // StartupIPI
402 * \brief Send an Inter-Processor Interrupt
403 * \param APICID Processor's Local APIC ID
404 * \param Vector Argument of some kind
405 * \param DeliveryMode Type of signal?
407 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
412 val = (Uint)APICID << 24;
413 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
414 gpMP_LocalAPIC->ICR[1].Val = val;
416 val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
417 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
418 gpMP_LocalAPIC->ICR[0].Val = val;
423 * \fn void Proc_Start(void)
424 * \brief Start process scheduler
426 void Proc_Start(void)
434 for( i = 0; i < giNumCPUs; i ++ )
437 if(Proc_Clone(0, 0) == 0)
439 gaCPUs[i].IdleThread = Proc_GetCurThread();
440 gaCPUs[i].IdleThread->ThreadName = "Idle Thread";
441 gaCPUs[i].IdleThread->NumTickets = 0; // Never called randomly
442 gaCPUs[i].IdleThread->Quantum = 1; // 1 slice quantum
443 for(;;) HALT(); // Just yeilds
445 gaCPUs[i].Current = NULL;
448 if( i != giProc_BootProcessorID ) {
453 // BSP still should run the current task
454 gaCPUs[0].Current = &gThreadZero;
456 // Start interrupts and wait for APs to come up
457 Log("Waiting for APs to come up\n");
458 __asm__ __volatile__ ("sti");
459 while( giNumInitingCPUs ) __asm__ __volatile__ ("hlt");
460 MM_FinishVirtualInit();
463 if(Proc_Clone(0, 0) == 0)
465 gpIdleThread = Proc_GetCurThread();
466 gpIdleThread->ThreadName = "Idle Thread";
467 gpIdleThread->NumTickets = 0; // Never called randomly
468 gpIdleThread->Quantum = 1; // 1 slice quantum
469 for(;;) HALT(); // Just yeilds
473 gCurrentThread = &gThreadZero;
475 // Start Interrupts (and hence scheduler)
476 __asm__ __volatile__("sti");
481 * \fn tThread *Proc_GetCurThread(void)
482 * \brief Gets the current thread
484 tThread *Proc_GetCurThread(void)
487 //return gaCPUs[ gaAPIC_to_CPU[gpMP_LocalAPIC->ID.Val&0xFF] ].Current;
488 return gaCPUs[ GetCPUNum() ].Current;
490 return gCurrentThread;
495 * \fn void Proc_ChangeStack(void)
496 * \brief Swaps the current stack for a new one (in the proper stack reigon)
498 void Proc_ChangeStack(void)
502 Uint curBase, newBase;
504 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
505 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
510 newBase = MM_NewKStack();
513 Panic("What the?? Unable to allocate space for initial kernel stack");
517 curBase = (Uint)&Kernel_Stack_Top;
519 LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
521 // Get ESP as a used size
523 LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
525 memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
526 // Get ESP as an offset in the new stack
529 ebp = newBase - (curBase - ebp);
531 // Repair EBPs & Stack Addresses
532 // Catches arguments also, but may trash stack-address-like values
533 for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
535 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
536 *(Uint*)tmpEbp += newBase - curBase;
539 Proc_GetCurThread()->KernelStack = newBase;
541 __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
542 __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
546 * \fn int Proc_Clone(Uint *Err, Uint Flags)
547 * \brief Clone the current process
549 int Proc_Clone(Uint *Err, Uint Flags)
552 tThread *cur = Proc_GetCurThread();
555 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
556 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
558 newThread = Threads_CloneTCB(Err, Flags);
559 if(!newThread) return -1;
561 // Initialise Memory Space (New Addr space or kernel stack)
562 if(Flags & CLONE_VM) {
563 newThread->MemState.CR3 = MM_Clone();
564 newThread->KernelStack = cur->KernelStack;
566 Uint tmpEbp, oldEsp = esp;
569 newThread->MemState.CR3 = cur->MemState.CR3;
572 newThread->KernelStack = MM_NewKStack();
574 if(newThread->KernelStack == 0) {
579 // Get ESP as a used size
580 esp = cur->KernelStack - esp;
582 memcpy( (void*)(newThread->KernelStack - esp), (void*)(cur->KernelStack - esp), esp );
583 // Get ESP as an offset in the new stack
584 esp = newThread->KernelStack - esp;
586 ebp = newThread->KernelStack - (cur->KernelStack - ebp);
588 // Repair EBPs & Stack Addresses
589 // Catches arguments also, but may trash stack-address-like values
590 for(tmpEbp = esp; tmpEbp < newThread->KernelStack; tmpEbp += 4)
592 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < cur->KernelStack)
593 *(Uint*)tmpEbp += newThread->KernelStack - cur->KernelStack;
597 // Save core machine state
598 newThread->SavedState.ESP = esp;
599 newThread->SavedState.EBP = ebp;
601 if(eip == SWITCH_MAGIC) {
602 outb(0x20, 0x20); // ACK Timer and return as child
603 __asm__ __volatile__ ("sti"); // Restart interrupts
608 newThread->SavedState.EIP = eip;
610 // Lock list and add to active
611 Threads_AddActive(newThread);
613 return newThread->TID;
617 * \fn int Proc_SpawnWorker(void)
618 * \brief Spawns a new worker thread
620 int Proc_SpawnWorker(void)
625 cur = Proc_GetCurThread();
628 new = malloc( sizeof(tThread) );
630 Warning("Proc_SpawnWorker - Out of heap space!\n");
633 memcpy(new, &gThreadZero, sizeof(tThread));
635 new->TID = giNextTID++;
636 // Create a new worker stack (in PID0's address space)
637 // The stack is relocated by this code
638 new->KernelStack = MM_NewWorkerStack();
640 // Get ESP and EBP based in the new stack
641 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
642 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
643 esp = new->KernelStack - (cur->KernelStack - esp);
644 ebp = new->KernelStack - (cur->KernelStack - ebp);
646 // Save core machine state
647 new->SavedState.ESP = esp;
648 new->SavedState.EBP = ebp;
650 if(eip == SWITCH_MAGIC) {
651 outb(0x20, 0x20); // ACK Timer and return as child
656 new->SavedState.EIP = eip;
658 new->Status = THREAD_STAT_ACTIVE;
659 Threads_AddActive( new );
665 * \fn Uint Proc_MakeUserStack(void)
666 * \brief Creates a new user stack
668 Uint Proc_MakeUserStack(void)
671 Uint base = USER_STACK_TOP - USER_STACK_SZ;
673 // Check Prospective Space
674 for( i = USER_STACK_SZ >> 12; i--; )
675 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
678 if(i != -1) return 0;
680 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
681 for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
682 MM_Allocate( base + (i<<12) );
684 return base + USER_STACK_SZ;
688 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
689 * \brief Starts a user task
691 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
693 Uint *stack = (void*)Proc_MakeUserStack();
698 //Log("stack = %p", stack);
701 stack -= DataSize/sizeof(*stack);
702 memcpy( stack, ArgV, DataSize );
704 //Log("stack = %p", stack);
708 // Adjust Arguments and environment
709 delta = (Uint)stack - (Uint)ArgV;
710 ArgV = (char**)stack;
711 for( i = 0; ArgV[i]; i++ )
715 // Do we care about EnvP?
718 for( i = 0; EnvP[i]; i++ )
723 // User Mode Segments
724 ss = 0x23; cs = 0x1B;
727 *--stack = (Uint)EnvP;
728 *--stack = (Uint)ArgV;
729 *--stack = (Uint)ArgC;
732 *--stack = 0; // Return Address
734 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
737 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
739 Uint *stack = (void*)Stack;
740 *--stack = SS; //Stack Segment
741 *--stack = Stack; //Stack Pointer
742 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
743 *--stack = CS; //Code Segment
746 *--stack = 0xAAAAAAAA; // eax
747 *--stack = 0xCCCCCCCC; // ecx
748 *--stack = 0xDDDDDDDD; // edx
749 *--stack = 0xBBBBBBBB; // ebx
750 *--stack = 0xD1D1D1D1; // edi
751 *--stack = 0x54545454; // esp - NOT POPED
752 *--stack = 0x51515151; // esi
753 *--stack = 0xB4B4B4B4; // ebp
760 __asm__ __volatile__ (
761 "mov %%eax,%%esp;\n\t" // Set stack pointer
767 "iret;\n\t" : : "a" (stack));
772 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
773 * \brief Demotes a process to a lower permission level
774 * \param Err Pointer to user's errno
775 * \param Dest New Permission Level
776 * \param Regs Pointer to user's register structure
778 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
780 int cpl = Regs->cs & 3;
782 if(Dest > 3 || Dest < 0) {
793 // Change the Segment Registers
794 Regs->cs = (((Dest+1)<<4) | Dest) - 8;
795 Regs->ss = ((Dest+1)<<4) | Dest;
796 // Check if the GP Segs are GDT, then change them
797 if(!(Regs->ds & 4)) Regs->ds = ((Dest+1)<<4) | Dest;
798 if(!(Regs->es & 4)) Regs->es = ((Dest+1)<<4) | Dest;
799 if(!(Regs->fs & 4)) Regs->fs = ((Dest+1)<<4) | Dest;
800 if(!(Regs->gs & 4)) Regs->gs = ((Dest+1)<<4) | Dest;
806 * \brief Calls a signal handler in user mode
807 * \note Used for signals
809 void Proc_CallFaultHandler(tThread *Thread)
811 // Rewinds the stack and calls the user function
813 __asm__ __volatile__ ("mov %0, %%ebp;\n\tcall Proc_ReturnToUser" :: "r"(Thread->FaultHandler));
818 * \fn void Proc_Scheduler(int CPU)
819 * \brief Swap current thread and clears dead threads
821 void Proc_Scheduler(int CPU)
826 // If the spinlock is set, let it complete
827 if(IS_LOCKED(&glThreadListLock)) return;
829 // Clear Delete Queue
830 while(gDeleteThreads)
832 thread = gDeleteThreads->Next;
833 if(gDeleteThreads->IsLocked) { // Only free if structure is unused
834 gDeleteThreads->Status = THREAD_STAT_NULL;
835 free( gDeleteThreads );
837 gDeleteThreads = thread;
840 // Check if there is any tasks running
841 if(giNumActiveThreads == 0) {
843 Log("No Active threads, sleeping");
847 gpMP_LocalAPIC->EOI.Val = 0;
851 __asm__ __volatile__ ("hlt");
855 // Get current thread
857 thread = gaCPUs[CPU].Current;
859 thread = gCurrentThread;
864 // Reduce remaining quantum and continue timeslice if non-zero
865 if(thread->Remaining--) return;
866 // Reset quantum for next call
867 thread->Remaining = thread->Quantum;
870 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
871 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
873 if(eip == SWITCH_MAGIC) return; // Check if a switch happened
875 // Save machine state
876 thread->SavedState.ESP = esp;
877 thread->SavedState.EBP = ebp;
878 thread->SavedState.EIP = eip;
881 // Get next thread to run
882 thread = Threads_GetNextToRun(CPU, thread);
884 // No avaliable tasks, just go into low power mode
889 thread = gaCPUs[CPU].IdleThread;
891 thread = gpIdleThread;
895 #if DEBUG_TRACE_SWITCH
896 Log("Switching to task %i, CR3 = 0x%x, EIP = %p",
898 thread->MemState.CR3,
899 thread->SavedState.EIP
903 // Set current thread
905 gaCPUs[CPU].Current = thread;
907 gCurrentThread = thread;
910 //Log("CPU = %i", CPU);
912 // Update Kernel Stack pointer
913 gTSSs[CPU].ESP0 = thread->KernelStack-4;
917 # error "Todo: Implement PAE Address space switching"
919 __asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
923 if(thread->SavedState.ESP > 0xC0000000
924 && thread->SavedState.ESP < thread->KernelStack-0x2000) {
925 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
930 __asm__ __volatile__ (
931 "mov %1, %%esp\n\t" // Restore ESP
932 "mov %2, %%ebp\n\t" // and EBP
933 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
934 "a"(SWITCH_MAGIC), "b"(thread->SavedState.ESP),
935 "d"(thread->SavedState.EBP), "c"(thread->SavedState.EIP)
937 for(;;); // Shouldn't reach here
941 EXPORT(Proc_SpawnWorker);