2 * AcessOS Microkernel Version
16 #define DEBUG_TRACE_SWITCH 0
17 #define DEBUG_DISABLE_DOUBLEFAULT 1
20 #define SWITCH_MAGIC 0xFF5317C8 // FF SWITCH - There is no code in this area
22 #define TIMER_BASE 1193182
23 #define TIMER_DIVISOR 11932 //~100Hz
30 Uint8 State; // 0: Unavaliable, 1: Idle, 2: Active
40 extern void APWait(void); // 16-bit AP pause code
41 extern void APStartup(void); // 16-bit AP startup code
42 extern Uint GetEIP(void); // start.asm
43 extern int GetCPUNum(void); // start.asm
44 extern Uint32 gaInitPageDir[1024]; // start.asm
45 extern char Kernel_Stack_Top[];
46 extern tShortSpinlock glThreadListLock;
49 extern tThread gThreadZero;
50 extern void Isr8(void); // Double Fault
51 extern void Proc_ReturnToUser(tVAddr Handler, Uint Argument, tVAddr KernelStack);
54 void ArchThreads_Init(void);
56 void MP_StartAP(int CPU);
57 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
59 void Proc_Start(void);
60 tThread *Proc_GetCurThread(void);
61 void Proc_ChangeStack(void);
62 int Proc_Clone(Uint *Err, Uint Flags);
63 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP);
64 void Proc_CallFaultHandler(tThread *Thread);
65 void Proc_Scheduler(int CPU);
68 // --- Multiprocessing ---
70 volatile int giNumInitingCPUs = 0;
71 tMPInfo *gMPFloatPtr = NULL;
72 volatile Uint32 giMP_TimerCount; // Start Count for Local APIC Timer
73 tAPIC *gpMP_LocalAPIC = NULL;
74 Uint8 gaAPIC_to_CPU[256] = {0};
75 tCPU gaCPUs[MAX_CPUS];
76 tTSS gaTSSs[MAX_CPUS]; // TSS Array
77 int giProc_BootProcessorID = 0;
79 tThread *gCurrentThread = NULL;
80 tThread *gpIdleThread = NULL;
83 Uint32 *gPML4s[4] = NULL;
85 tTSS *gTSSs = NULL; // Pointer to TSS array
87 // --- Error Recovery ---
88 char gaDoubleFaultStack[1024] __attribute__ ((section(".padata")));
89 tTSS gDoubleFault_TSS = {
90 .ESP0 = (Uint)&gaDoubleFaultStack[1024],
92 .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
94 .ESP = (Uint)&gaDoubleFaultStack[1024],
95 .CS = 0x08, .SS = 0x10,
96 .DS = 0x10, .ES = 0x10,
97 .FS = 0x10, .GS = 0x10,
102 * \fn void ArchThreads_Init(void)
103 * \brief Starts the process scheduler
105 void ArchThreads_Init(void)
112 // Mark BSP as active
115 // -- Initialise Multiprocessing
116 // Find MP Floating Table
117 // - EBDA/Last 1Kib (640KiB)
118 for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
119 if( *(Uint*)(pos) == MPPTR_IDENT ) {
120 Log("Possible %p", pos);
121 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
122 gMPFloatPtr = (void*)pos;
126 // - Last KiB (512KiB base mem)
128 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
129 if( *(Uint*)(pos) == MPPTR_IDENT ) {
130 Log("Possible %p", pos);
131 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
132 gMPFloatPtr = (void*)pos;
139 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
140 if( *(Uint*)(pos) == MPPTR_IDENT ) {
141 Log("Possible %p", pos);
142 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
143 gMPFloatPtr = (void*)pos;
149 // If the MP Table Exists, parse it
154 Log("gMPFloatPtr = %p", gMPFloatPtr);
155 Log("*gMPFloatPtr = {");
156 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
157 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
158 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
159 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
160 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
161 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
162 gMPFloatPtr->Features[0], gMPFloatPtr->Features[1],
163 gMPFloatPtr->Features[2], gMPFloatPtr->Features[3],
164 gMPFloatPtr->Features[4]
168 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
169 Log("mptable = %p", mptable);
171 Log("\t.Sig = 0x%08x", mptable->Sig);
172 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
173 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
174 Log("\t.Checksum = 0x%02x", mptable->Checksum);
175 Log("\t.OEMID = '%8c'", mptable->OemID);
176 Log("\t.ProductID = '%8c'", mptable->ProductID);
177 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
178 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
179 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
180 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
181 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
182 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
185 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
187 ents = mptable->Entries;
190 for( i = 0; i < mptable->EntryCount; i ++ )
197 Log("%i: Processor", i);
198 Log("\t.APICID = %i", ents->Proc.APICID);
199 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
200 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
201 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
202 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
205 if( !(ents->Proc.CPUFlags & 1) ) {
210 // Check if there is too many processors
211 if(giNumCPUs >= MAX_CPUS) {
212 giNumCPUs ++; // If `giNumCPUs` > MAX_CPUS later, it will be clipped
216 // Initialise CPU Info
217 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
218 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
219 gaCPUs[giNumCPUs].State = 0;
223 if( ents->Proc.CPUFlags & 2 ) {
224 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);
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 #if !DEBUG_DISABLE_DOUBLEFAULT
290 // Initialise Double Fault TSS
291 gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
292 gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
293 gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
295 // Set double fault IDT to use the new TSS
296 gIDT[8].OffsetLo = 0;
298 gIDT[8].Flags = 0x8500;
299 gIDT[8].OffsetHi = 0;
302 // Set timer frequency
303 outb(0x43, 0x34); // Set Channel 0, Low/High, Rate Generator
304 outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
305 outb(0x40, (TIMER_DIVISOR>>8)&0xFF); // High Byte
307 Log("Timer Frequency %i.%03i Hz",
308 TIMER_BASE/TIMER_DIVISOR,
309 ((Uint64)TIMER_BASE*1000/TIMER_DIVISOR)%1000
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) & 0xFFFF;
343 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
348 // Load the BSP's TSS
349 __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
350 // Set Current Thread and CPU Number in DR0 and DR1
351 __asm__ __volatile__ ("mov %0, %%db0"::"r"(&gThreadZero));
352 __asm__ __volatile__ ("mov %0, %%db1"::"r"(0));
355 gaCPUs[0].Current = &gThreadZero;
357 gCurrentThread = &gThreadZero;
359 gThreadZero.CurCPU = 0;
362 gThreadZero.MemState.PDP[0] = 0;
363 gThreadZero.MemState.PDP[1] = 0;
364 gThreadZero.MemState.PDP[2] = 0;
366 gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
369 // Create Per-Process Data Block
370 if( !MM_Allocate(MM_PPD_CFG) )
372 Panic("OOM - No space for initiali Per-Process Config");
380 void MP_StartAP(int CPU)
382 Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
384 // Set location of AP startup code and mark for a warm restart
385 *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
386 *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
387 outb(0x70, 0x0F); outb(0x71, 0x0A); // Set warm reset flag
388 MP_SendIPI(gaCPUs[CPU].APICID, 0, 5); // Init IPI
391 inb(0x80); inb(0x80); inb(0x80); inb(0x80);
393 // TODO: Use a better address, preferably registered with the MM
394 // - MM_AllocDMA mabye?
396 *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA; // Far JMP
397 *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0); // IP
398 *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF; // CS
399 // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
401 MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6); // StartupIPI
407 * \brief Send an Inter-Processor Interrupt
408 * \param APICID Processor's Local APIC ID
409 * \param Vector Argument of some kind
410 * \param DeliveryMode Type of signal?
412 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
417 val = (Uint)APICID << 24;
418 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
419 gpMP_LocalAPIC->ICR[1].Val = val;
421 val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
422 Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
423 gpMP_LocalAPIC->ICR[0].Val = val;
428 * \fn void Proc_Start(void)
429 * \brief Start process scheduler
431 void Proc_Start(void)
439 for( i = 0; i < giNumCPUs; i ++ )
442 if(i) gaCPUs[i].Current = NULL;
445 if( (tid = Proc_Clone(0, 0)) == 0)
447 for(;;) HALT(); // Just yeilds
449 gaCPUs[i].IdleThread = Threads_GetThread(tid);
450 gaCPUs[i].IdleThread->ThreadName = "Idle Thread";
451 Threads_SetPriority( gaCPUs[i].IdleThread, -1 ); // Never called randomly
452 gaCPUs[i].IdleThread->Quantum = 1; // 1 slice quantum
456 if( i != giProc_BootProcessorID ) {
461 // BSP still should run the current task
462 gaCPUs[0].Current = &gThreadZero;
464 // Start interrupts and wait for APs to come up
465 Log("Waiting for APs to come up\n");
466 __asm__ __volatile__ ("sti");
467 while( giNumInitingCPUs ) __asm__ __volatile__ ("hlt");
470 if(Proc_Clone(0, 0) == 0)
472 gpIdleThread = Proc_GetCurThread();
473 gpIdleThread->ThreadName = "Idle Thread";
474 Threads_SetPriority( gpIdleThread, -1 ); // Never called randomly
475 gpIdleThread->Quantum = 1; // 1 slice quantum
476 for(;;) HALT(); // Just yeilds
480 gCurrentThread = &gThreadZero;
482 // Start Interrupts (and hence scheduler)
483 __asm__ __volatile__("sti");
485 MM_FinishVirtualInit();
489 * \fn tThread *Proc_GetCurThread(void)
490 * \brief Gets the current thread
492 tThread *Proc_GetCurThread(void)
495 return gaCPUs[ GetCPUNum() ].Current;
497 return gCurrentThread;
502 * \fn void Proc_ChangeStack(void)
503 * \brief Swaps the current stack for a new one (in the proper stack reigon)
505 void Proc_ChangeStack(void)
509 Uint curBase, newBase;
511 __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
512 __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
517 newBase = MM_NewKStack();
520 Panic("What the?? Unable to allocate space for initial kernel stack");
524 curBase = (Uint)&Kernel_Stack_Top;
526 LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
528 // Get ESP as a used size
530 LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
532 memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
533 // Get ESP as an offset in the new stack
536 ebp = newBase - (curBase - ebp);
538 // Repair EBPs & Stack Addresses
539 // Catches arguments also, but may trash stack-address-like values
540 for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
542 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
543 *(Uint*)tmpEbp += newBase - curBase;
546 Proc_GetCurThread()->KernelStack = newBase;
548 __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
549 __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
553 * \fn int Proc_Clone(Uint *Err, Uint Flags)
554 * \brief Clone the current process
556 int Proc_Clone(Uint *Err, Uint Flags)
559 tThread *cur = Proc_GetCurThread();
562 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
563 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
565 newThread = Threads_CloneTCB(Err, Flags);
566 if(!newThread) return -1;
568 // Initialise Memory Space (New Addr space or kernel stack)
569 if(Flags & CLONE_VM) {
570 newThread->MemState.CR3 = MM_Clone();
572 if(newThread->MemState.CR3 == 0) {
573 Threads_Kill(newThread, -2);
576 newThread->KernelStack = cur->KernelStack;
578 Uint tmpEbp, oldEsp = esp;
582 # warning "PAE Unimplemented"
584 newThread->MemState.CR3 = cur->MemState.CR3;
588 newThread->KernelStack = MM_NewKStack();
590 if(newThread->KernelStack == 0) {
591 Threads_Kill(newThread, -2);
595 // Get ESP as a used size
596 esp = cur->KernelStack - esp;
598 memcpy( (void*)(newThread->KernelStack - esp), (void*)(cur->KernelStack - esp), esp );
599 // Get ESP as an offset in the new stack
600 esp = newThread->KernelStack - esp;
602 ebp = newThread->KernelStack - (cur->KernelStack - ebp);
604 // Repair EBPs & Stack Addresses
605 // Catches arguments also, but may trash stack-address-like values
606 for(tmpEbp = esp; tmpEbp < newThread->KernelStack; tmpEbp += 4)
608 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < cur->KernelStack)
609 *(Uint*)tmpEbp += newThread->KernelStack - cur->KernelStack;
613 // Save core machine state
614 newThread->SavedState.ESP = esp;
615 newThread->SavedState.EBP = ebp;
617 if(eip == SWITCH_MAGIC) {
618 __asm__ __volatile__ ("mov %0, %%db0" : : "r" (newThread) );
622 gpMP_LocalAPIC->EOI.Val = 0;
625 outb(0x20, 0x20); // ACK Timer and return as child
626 __asm__ __volatile__ ("sti"); // Restart interrupts
631 newThread->SavedState.EIP = eip;
633 // Lock list and add to active
634 Threads_AddActive(newThread);
636 return newThread->TID;
640 * \fn int Proc_SpawnWorker(void)
641 * \brief Spawns a new worker thread
643 int Proc_SpawnWorker(void)
648 cur = Proc_GetCurThread();
651 new = Threads_CloneThreadZero();
653 Warning("Proc_SpawnWorker - Out of heap space!\n");
656 // Create a new worker stack (in PID0's address space)
657 // - The stack is relocated by this function
658 new->KernelStack = MM_NewWorkerStack();
660 // Get ESP and EBP based in the new stack
661 __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
662 __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
663 esp = new->KernelStack - (cur->KernelStack - esp);
664 ebp = new->KernelStack - (cur->KernelStack - ebp);
666 // Save core machine state
667 new->SavedState.ESP = esp;
668 new->SavedState.EBP = ebp;
670 if(eip == SWITCH_MAGIC) {
671 __asm__ __volatile__ ("mov %0, %%db0" : : "r"(new));
675 gpMP_LocalAPIC->EOI.Val = 0;
678 outb(0x20, 0x20); // ACK Timer and return as child
679 __asm__ __volatile__ ("sti"); // Restart interrupts
684 new->SavedState.EIP = eip;
686 Threads_AddActive( new );
692 * \fn Uint Proc_MakeUserStack(void)
693 * \brief Creates a new user stack
695 Uint Proc_MakeUserStack(void)
698 Uint base = USER_STACK_TOP - USER_STACK_SZ;
700 // Check Prospective Space
701 for( i = USER_STACK_SZ >> 12; i--; )
702 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
705 if(i != -1) return 0;
707 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
708 for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
710 if( !MM_Allocate( base + (i<<12) ) )
712 Warning("OOM: Proc_MakeUserStack");
717 return base + USER_STACK_SZ;
721 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
722 * \brief Starts a user task
724 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
726 Uint *stack = (void*)Proc_MakeUserStack();
731 //Log("stack = %p", stack);
734 stack -= DataSize/sizeof(*stack);
735 memcpy( stack, ArgV, DataSize );
737 //Log("stack = %p", stack);
741 // Adjust Arguments and environment
742 delta = (Uint)stack - (Uint)ArgV;
743 ArgV = (char**)stack;
744 for( i = 0; ArgV[i]; i++ )
748 // Do we care about EnvP?
751 for( i = 0; EnvP[i]; i++ )
756 // User Mode Segments
757 ss = 0x23; cs = 0x1B;
760 *--stack = (Uint)EnvP;
761 *--stack = (Uint)ArgV;
762 *--stack = (Uint)ArgC;
765 *--stack = 0; // Return Address
767 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
770 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
772 Uint *stack = (void*)Stack;
773 *--stack = SS; //Stack Segment
774 *--stack = Stack; //Stack Pointer
775 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
776 *--stack = CS; //Code Segment
779 *--stack = 0xAAAAAAAA; // eax
780 *--stack = 0xCCCCCCCC; // ecx
781 *--stack = 0xDDDDDDDD; // edx
782 *--stack = 0xBBBBBBBB; // ebx
783 *--stack = 0xD1D1D1D1; // edi
784 *--stack = 0x54545454; // esp - NOT POPED
785 *--stack = 0x51515151; // esi
786 *--stack = 0xB4B4B4B4; // ebp
793 __asm__ __volatile__ (
794 "mov %%eax,%%esp;\n\t" // Set stack pointer
800 "iret;\n\t" : : "a" (stack));
805 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
806 * \brief Demotes a process to a lower permission level
807 * \param Err Pointer to user's errno
808 * \param Dest New Permission Level
809 * \param Regs Pointer to user's register structure
811 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
813 int cpl = Regs->cs & 3;
815 if(Dest > 3 || Dest < 0) {
826 // Change the Segment Registers
827 Regs->cs = (((Dest+1)<<4) | Dest) - 8;
828 Regs->ss = ((Dest+1)<<4) | Dest;
829 // Check if the GP Segs are GDT, then change them
830 if(!(Regs->ds & 4)) Regs->ds = ((Dest+1)<<4) | Dest;
831 if(!(Regs->es & 4)) Regs->es = ((Dest+1)<<4) | Dest;
832 if(!(Regs->fs & 4)) Regs->fs = ((Dest+1)<<4) | Dest;
833 if(!(Regs->gs & 4)) Regs->gs = ((Dest+1)<<4) | Dest;
839 * \brief Calls a signal handler in user mode
840 * \note Used for signals
842 void Proc_CallFaultHandler(tThread *Thread)
844 // Rewinds the stack and calls the user function
846 Proc_ReturnToUser( Thread->FaultHandler, Thread->CurFaultNum, Thread->KernelStack );
851 * \fn void Proc_Scheduler(int CPU)
852 * \brief Swap current thread and clears dead threads
854 void Proc_Scheduler(int CPU)
859 // If the spinlock is set, let it complete
860 if(IS_LOCKED(&glThreadListLock)) return;
862 // Get current thread
864 thread = gaCPUs[CPU].Current;
866 thread = gCurrentThread;
871 // Reduce remaining quantum and continue timeslice if non-zero
872 if( thread->Remaining-- )
874 // Reset quantum for next call
875 thread->Remaining = thread->Quantum;
878 __asm__ __volatile__ ( "mov %%esp, %0" : "=r" (esp) );
879 __asm__ __volatile__ ( "mov %%ebp, %0" : "=r" (ebp) );
881 if(eip == SWITCH_MAGIC) return; // Check if a switch happened
883 // Save machine state
884 thread->SavedState.ESP = esp;
885 thread->SavedState.EBP = ebp;
886 thread->SavedState.EIP = eip;
889 // Get next thread to run
890 thread = Threads_GetNextToRun(CPU, thread);
892 // No avaliable tasks, just go into low power mode (idle thread)
895 thread = gaCPUs[CPU].IdleThread;
896 Log("CPU %i Running Idle Thread", CPU);
898 thread = gpIdleThread;
902 // Set current thread
904 gaCPUs[CPU].Current = thread;
906 gCurrentThread = thread;
909 #if DEBUG_TRACE_SWITCH
910 Log("Switching to task %i, CR3 = 0x%x, EIP = %p",
912 thread->MemState.CR3,
913 thread->SavedState.EIP
917 #if USE_MP // MP Debug
918 Log("CPU = %i, Thread %p", CPU, thread);
921 // Update Kernel Stack pointer
922 gTSSs[CPU].ESP0 = thread->KernelStack-4;
925 if(thread->SavedState.ESP > 0xC0000000
926 && thread->SavedState.ESP < thread->KernelStack-0x2000) {
927 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
932 # error "Todo: Implement PAE Address space switching"
935 __asm__ __volatile__ (
936 "mov %4, %%cr3\n\t" // Set address space
937 "mov %1, %%esp\n\t" // Restore ESP
938 "mov %2, %%ebp\n\t" // and EBP
939 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
940 "a"(SWITCH_MAGIC), "b"(thread->SavedState.ESP),
941 "d"(thread->SavedState.EBP), "c"(thread->SavedState.EIP),
942 "r"(thread->MemState.CR3)
945 for(;;); // Shouldn't reach here
949 EXPORT(Proc_SpawnWorker);