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;
88 Uint32 *gPML4s[4] = NULL;
90 tTSS *gTSSs = NULL; // Pointer to TSS array
92 // --- Error Recovery ---
93 char gaDoubleFaultStack[1024] __attribute__ ((section(".padata")));
94 tTSS gDoubleFault_TSS = {
95 .ESP0 = (Uint)&gaDoubleFaultStack[1024],
97 .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
99 .ESP = (Uint)&gaDoubleFaultStack[1024],
100 .CS = 0x08, .SS = 0x10,
101 .DS = 0x10, .ES = 0x10,
102 .FS = 0x10, .GS = 0x10,
107 * \fn void ArchThreads_Init(void)
108 * \brief Starts the process scheduler
110 void ArchThreads_Init(void)
117 // Mark BSP as active
120 // -- Initialise Multiprocessing
121 // Find MP Floating Table
122 // - EBDA/Last 1Kib (640KiB)
123 for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
124 if( *(Uint*)(pos) == MPPTR_IDENT ) {
125 Log("Possible %p", pos);
126 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
127 gMPFloatPtr = (void*)pos;
131 // - Last KiB (512KiB base mem)
133 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
134 if( *(Uint*)(pos) == MPPTR_IDENT ) {
135 Log("Possible %p", pos);
136 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
137 gMPFloatPtr = (void*)pos;
144 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
145 if( *(Uint*)(pos) == MPPTR_IDENT ) {
146 Log("Possible %p", pos);
147 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
148 gMPFloatPtr = (void*)pos;
154 // If the MP Table Exists, parse it
159 Log("gMPFloatPtr = %p", gMPFloatPtr);
160 Log("*gMPFloatPtr = {");
161 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
162 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
163 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
164 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
165 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
166 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
167 gMPFloatPtr->Features[0], gMPFloatPtr->Features[1],
168 gMPFloatPtr->Features[2], gMPFloatPtr->Features[3],
169 gMPFloatPtr->Features[4]
173 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
174 Log("mptable = %p", mptable);
176 Log("\t.Sig = 0x%08x", mptable->Sig);
177 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
178 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
179 Log("\t.Checksum = 0x%02x", mptable->Checksum);
180 Log("\t.OEMID = '%8c'", mptable->OemID);
181 Log("\t.ProductID = '%8c'", mptable->ProductID);
182 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
183 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
184 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
185 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
186 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
187 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
190 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
192 ents = mptable->Entries;
195 for( i = 0; i < mptable->EntryCount; i ++ )
202 Log("%i: Processor", i);
203 Log("\t.APICID = %i", ents->Proc.APICID);
204 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
205 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
206 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
207 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
210 if( !(ents->Proc.CPUFlags & 1) ) {
215 // Check if there is too many processors
216 if(giNumCPUs >= MAX_CPUS) {
217 giNumCPUs ++; // If `giNumCPUs` > MAX_CPUS later, it will be clipped
221 // Initialise CPU Info
222 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
223 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
224 gaCPUs[giNumCPUs].State = 0;
228 if( ents->Proc.CPUFlags & 2 ) {
229 giProc_BootProcessorID = giNumCPUs-1;
238 Log("\t.ID = %i", ents->Bus.ID);
239 Log("\t.TypeString = '%6C'", ents->Bus.TypeString);
243 Log("%i: I/O APIC", i);
244 Log("\t.ID = %i", ents->IOAPIC.ID);
245 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
246 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
247 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
249 case 3: // I/O Interrupt Assignment
251 Log("%i: I/O Interrupt Assignment", i);
252 Log("\t.IntType = %i", ents->IOInt.IntType);
253 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
254 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
255 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
256 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
257 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
259 case 4: // Local Interrupt Assignment
261 Log("%i: Local Interrupt Assignment", i);
262 Log("\t.IntType = %i", ents->LocalInt.IntType);
263 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
264 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
265 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
266 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
267 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
270 Log("%i: Unknown (%i)", i, ents->Type);
274 ents = (void*)( (Uint)ents + entSize );
277 if( giNumCPUs > MAX_CPUS ) {
278 Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
279 giNumCPUs = MAX_CPUS;
284 Log("No MP Table was found, assuming uniprocessor\n");
291 MM_FinishVirtualInit();
295 // Initialise Double Fault TSS
296 gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
297 gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
298 gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
300 // Set double fault IDT to use the new TSS
301 gIDT[8].OffsetLo = 0;
303 gIDT[8].Flags = 0x8500;
304 gIDT[8].OffsetHi = 0;
307 // Set timer frequency
308 outb(0x43, 0x34); // Set Channel 0, Low/High, Rate Generator
309 outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
310 outb(0x40, (TIMER_DIVISOR>>8)&0xFF); // High Byte
313 // Get the count setting for APIC timer
314 Log("Determining APIC Count");
315 __asm__ __volatile__ ("sti");
316 while( giMP_TimerCount == 0 ) __asm__ __volatile__ ("hlt");
317 __asm__ __volatile__ ("cli");
318 Log("APIC Count %i", giMP_TimerCount);
320 Uint64 freq = giMP_TimerCount;
321 freq /= TIMER_DIVISOR;
323 if( (freq /= 1000) < 2*1000)
324 Log("Bus Frequency %i KHz", freq);
325 else if( (freq /= 1000) < 2*1000)
326 Log("Bus Frequency %i MHz", freq);
327 else if( (freq /= 1000) < 2*1000)
328 Log("Bus Frequency %i GHz", freq);
330 Log("Bus Frequency %i THz", freq);
333 // Initialise Normal TSS(s)
334 for(pos=0;pos<giNumCPUs;pos++)
339 gTSSs[pos].SS0 = 0x10;
340 gTSSs[pos].ESP0 = 0; // Set properly by scheduler
341 gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
342 gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
343 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
348 // Load the BSP's TSS
349 __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
352 gaCPUs[0].Current = &gThreadZero;
354 gCurrentThread = &gThreadZero;
356 gThreadZero.CurCPU = 0;
359 gThreadZero.MemState.PDP[0] = 0;
360 gThreadZero.MemState.PDP[1] = 0;
361 gThreadZero.MemState.PDP[2] = 0;
363 gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
366 // Create Per-Process Data Block
367 MM_Allocate(MM_PPD_CFG);
374 void MP_StartAP(int CPU)
376 Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
378 // Set location of AP startup code and mark for a warm restart
379 *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
380 *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
381 outb(0x70, 0x0F); outb(0x71, 0x0A); // Warm Reset
382 MP_SendIPI(gaCPUs[CPU].APICID, 0, 5); // Init IPI
385 inb(0x80); inb(0x80); inb(0x80); inb(0x80);
387 // TODO: Use a better address, preferably registered with the MM
388 // - MM_AllocDMA mabye?
390 *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA; // Far JMP
391 *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0); // IP
392 *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF; // CS
393 // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
395 MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6); // StartupIPI
401 * \brief Send an Inter-Processor Interrupt
402 * \param APICID Processor's Local APIC ID
403 * \param Vector Argument of some kind
404 * \param DeliveryMode Type of signal?
406 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
411 val = (Uint)APICID << 24;
412 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
413 gpMP_LocalAPIC->ICR[1].Val = val;
415 val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
416 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
417 gpMP_LocalAPIC->ICR[0].Val = val;
422 * \fn void Proc_Start(void)
423 * \brief Start process scheduler
425 void Proc_Start(void)
433 for( i = 0; i < giNumCPUs; i ++ )
436 if(Proc_Clone(0, 0) == 0)
438 gaCPUs[i].IdleThread = Proc_GetCurThread();
439 gaCPUs[i].IdleThread->ThreadName = "Idle Thread";
440 gaCPUs[i].IdleThread->NumTickets = 0; // Never called randomly
441 gaCPUs[i].IdleThread->Quantum = 1; // 1 slice quantum
442 for(;;) HALT(); // Just yeilds
444 gaCPUs[i].Current = NULL;
447 if( i != giProc_BootProcessorID ) {
452 // BSP still should run the current task
453 gaCPUs[0].Current = &gThreadZero;
455 // Start interrupts and wait for APs to come up
456 Log("Waiting for APs to come up\n");
457 __asm__ __volatile__ ("sti");
458 while( giNumInitingCPUs ) __asm__ __volatile__ ("hlt");
459 MM_FinishVirtualInit();
462 if(Proc_Clone(0, 0) == 0)
464 tThread *cur = Proc_GetCurThread();
465 cur->ThreadName = "Idle Thread";
466 Threads_SetTickets(0); // Never called randomly
467 cur->Quantum = 1; // 1 slice quantum
468 for(;;) HALT(); // Just yeilds
472 gCurrentThread = &gThreadZero;
474 // Start Interrupts (and hence scheduler)
475 __asm__ __volatile__("sti");
480 * \fn tThread *Proc_GetCurThread(void)
481 * \brief Gets the current thread
483 tThread *Proc_GetCurThread(void)
486 //return gaCPUs[ gaAPIC_to_CPU[gpMP_LocalAPIC->ID.Val&0xFF] ].Current;
487 return gaCPUs[ GetCPUNum() ].Current;
489 return gCurrentThread;
494 * \fn void Proc_ChangeStack(void)
495 * \brief Swaps the current stack for a new one (in the proper stack reigon)
497 void Proc_ChangeStack(void)
501 Uint curBase, newBase;
503 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
504 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
509 newBase = MM_NewKStack();
512 Panic("What the?? Unable to allocate space for initial kernel stack");
516 curBase = (Uint)&Kernel_Stack_Top;
518 LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
520 // Get ESP as a used size
522 LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
524 memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
525 // Get ESP as an offset in the new stack
528 ebp = newBase - (curBase - ebp);
530 // Repair EBPs & Stack Addresses
531 // Catches arguments also, but may trash stack-address-like values
532 for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
534 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
535 *(Uint*)tmpEbp += newBase - curBase;
538 Proc_GetCurThread()->KernelStack = newBase;
540 __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
541 __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
545 * \fn int Proc_Clone(Uint *Err, Uint Flags)
546 * \brief Clone the current process
548 int Proc_Clone(Uint *Err, Uint Flags)
551 tThread *cur = Proc_GetCurThread();
554 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
555 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
557 newThread = Threads_CloneTCB(Err, Flags);
558 if(!newThread) return -1;
560 // Initialise Memory Space (New Addr space or kernel stack)
561 if(Flags & CLONE_VM) {
562 newThread->MemState.CR3 = MM_Clone();
563 newThread->KernelStack = cur->KernelStack;
565 Uint tmpEbp, oldEsp = esp;
568 newThread->MemState.CR3 = cur->MemState.CR3;
571 newThread->KernelStack = MM_NewKStack();
573 if(newThread->KernelStack == 0) {
578 // Get ESP as a used size
579 esp = cur->KernelStack - esp;
581 memcpy( (void*)(newThread->KernelStack - esp), (void*)(cur->KernelStack - esp), esp );
582 // Get ESP as an offset in the new stack
583 esp = newThread->KernelStack - esp;
585 ebp = newThread->KernelStack - (cur->KernelStack - ebp);
587 // Repair EBPs & Stack Addresses
588 // Catches arguments also, but may trash stack-address-like values
589 for(tmpEbp = esp; tmpEbp < newThread->KernelStack; tmpEbp += 4)
591 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < cur->KernelStack)
592 *(Uint*)tmpEbp += newThread->KernelStack - cur->KernelStack;
596 // Save core machine state
597 newThread->SavedState.ESP = esp;
598 newThread->SavedState.EBP = ebp;
600 if(eip == SWITCH_MAGIC) {
601 outb(0x20, 0x20); // ACK Timer and return as child
602 __asm__ __volatile__ ("sti"); // Restart interrupts
607 newThread->SavedState.EIP = eip;
609 // Lock list and add to active
610 Threads_AddActive(newThread);
612 return newThread->TID;
616 * \fn int Proc_SpawnWorker(void)
617 * \brief Spawns a new worker thread
619 int Proc_SpawnWorker(void)
624 cur = Proc_GetCurThread();
627 new = malloc( sizeof(tThread) );
629 Warning("Proc_SpawnWorker - Out of heap space!\n");
632 memcpy(new, &gThreadZero, sizeof(tThread));
634 new->TID = giNextTID++;
635 // Create a new worker stack (in PID0's address space)
636 // The stack is relocated by this code
637 new->KernelStack = MM_NewWorkerStack();
639 // Get ESP and EBP based in the new stack
640 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
641 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
642 esp = new->KernelStack - (cur->KernelStack - esp);
643 ebp = new->KernelStack - (cur->KernelStack - ebp);
645 // Save core machine state
646 new->SavedState.ESP = esp;
647 new->SavedState.EBP = ebp;
649 if(eip == SWITCH_MAGIC) {
650 outb(0x20, 0x20); // ACK Timer and return as child
655 new->SavedState.EIP = eip;
657 new->Status = THREAD_STAT_ACTIVE;
658 Threads_AddActive( new );
664 * \fn Uint Proc_MakeUserStack(void)
665 * \brief Creates a new user stack
667 Uint Proc_MakeUserStack(void)
670 Uint base = USER_STACK_TOP - USER_STACK_SZ;
672 // Check Prospective Space
673 for( i = USER_STACK_SZ >> 12; i--; )
674 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
677 if(i != -1) return 0;
679 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
680 for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
681 MM_Allocate( base + (i<<12) );
683 return base + USER_STACK_SZ;
687 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
688 * \brief Starts a user task
690 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
692 Uint *stack = (void*)Proc_MakeUserStack();
697 //Log("stack = %p", stack);
700 stack -= DataSize/sizeof(*stack);
701 memcpy( stack, ArgV, DataSize );
703 //Log("stack = %p", stack);
707 // Adjust Arguments and environment
708 delta = (Uint)stack - (Uint)ArgV;
709 ArgV = (char**)stack;
710 for( i = 0; ArgV[i]; i++ )
714 // Do we care about EnvP?
717 for( i = 0; EnvP[i]; i++ )
722 // User Mode Segments
723 ss = 0x23; cs = 0x1B;
726 *--stack = (Uint)EnvP;
727 *--stack = (Uint)ArgV;
728 *--stack = (Uint)ArgC;
731 *--stack = 0; // Return Address
733 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
736 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
738 Uint *stack = (void*)Stack;
739 *--stack = SS; //Stack Segment
740 *--stack = Stack; //Stack Pointer
741 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
742 *--stack = CS; //Code Segment
745 *--stack = 0xAAAAAAAA; // eax
746 *--stack = 0xCCCCCCCC; // ecx
747 *--stack = 0xDDDDDDDD; // edx
748 *--stack = 0xBBBBBBBB; // ebx
749 *--stack = 0xD1D1D1D1; // edi
750 *--stack = 0x54545454; // esp - NOT POPED
751 *--stack = 0x51515151; // esi
752 *--stack = 0xB4B4B4B4; // ebp
759 __asm__ __volatile__ (
760 "mov %%eax,%%esp;\n\t" // Set stack pointer
766 "iret;\n\t" : : "a" (stack));
771 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
772 * \brief Demotes a process to a lower permission level
773 * \param Err Pointer to user's errno
774 * \param Dest New Permission Level
775 * \param Regs Pointer to user's register structure
777 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
779 int cpl = Regs->cs & 3;
781 if(Dest > 3 || Dest < 0) {
792 // Change the Segment Registers
793 Regs->cs = (((Dest+1)<<4) | Dest) - 8;
794 Regs->ss = ((Dest+1)<<4) | Dest;
795 // Check if the GP Segs are GDT, then change them
796 if(!(Regs->ds & 4)) Regs->ds = ((Dest+1)<<4) | Dest;
797 if(!(Regs->es & 4)) Regs->es = ((Dest+1)<<4) | Dest;
798 if(!(Regs->fs & 4)) Regs->fs = ((Dest+1)<<4) | Dest;
799 if(!(Regs->gs & 4)) Regs->gs = ((Dest+1)<<4) | Dest;
805 * \brief Calls a signal handler in user mode
806 * \note Used for signals
808 void Proc_CallFaultHandler(tThread *Thread)
810 // Rewinds the stack and calls the user function
812 __asm__ __volatile__ ("mov %0, %%ebp;\n\tcall Proc_ReturnToUser" :: "r"(Thread->FaultHandler));
817 * \fn void Proc_Scheduler(int CPU)
818 * \brief Swap current thread and clears dead threads
820 void Proc_Scheduler(int CPU)
825 // If the spinlock is set, let it complete
826 if(IS_LOCKED(&glThreadListLock)) return;
828 // Clear Delete Queue
829 while(gDeleteThreads)
831 thread = gDeleteThreads->Next;
832 if(gDeleteThreads->IsLocked) { // Only free if structure is unused
833 gDeleteThreads->Status = THREAD_STAT_NULL;
834 free( gDeleteThreads );
836 gDeleteThreads = thread;
839 // Check if there is any tasks running
840 if(giNumActiveThreads == 0) {
842 Log("No Active threads, sleeping");
846 gpMP_LocalAPIC->EOI.Val = 0;
850 __asm__ __volatile__ ("hlt");
854 // Get current thread
856 thread = gaCPUs[CPU].Current;
858 thread = gCurrentThread;
863 // Reduce remaining quantum and continue timeslice if non-zero
864 if(thread->Remaining--) return;
865 // Reset quantum for next call
866 thread->Remaining = thread->Quantum;
869 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
870 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
872 if(eip == SWITCH_MAGIC) return; // Check if a switch happened
874 // Save machine state
875 thread->SavedState.ESP = esp;
876 thread->SavedState.EBP = ebp;
877 thread->SavedState.EIP = eip;
880 // Get next thread to run
881 thread = Threads_GetNextToRun(CPU, thread);
883 // No avaliable tasks, just go into low power mode
887 thread = gaCPUs[CPU].IdleThread;
890 #if DEBUG_TRACE_SWITCH
891 Log("Switching to task %i, CR3 = 0x%x, EIP = %p",
893 thread->MemState.CR3,
894 thread->SavedState.EIP
898 // Set current thread
900 gaCPUs[CPU].Current = thread;
902 gCurrentThread = thread;
905 //Log("CPU = %i", CPU);
907 // Update Kernel Stack pointer
908 gTSSs[CPU].ESP0 = thread->KernelStack-4;
912 # error "Todo: Implement PAE Address space switching"
914 __asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
918 if(thread->SavedState.ESP > 0xC0000000
919 && thread->SavedState.ESP < thread->KernelStack-0x2000) {
920 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
925 __asm__ __volatile__ (
926 "mov %1, %%esp\n\t" // Restore ESP
927 "mov %2, %%ebp\n\t" // and EBP
928 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
929 "a"(SWITCH_MAGIC), "b"(thread->SavedState.ESP),
930 "d"(thread->SavedState.EBP), "c"(thread->SavedState.EIP)
932 for(;;); // Shouldn't reach here
936 EXPORT(Proc_SpawnWorker);