2 * AcessOS Microkernel Version
16 #define DEBUG_TRACE_SWITCH 0
19 #define SWITCH_MAGIC 0x55ECAFFF##FFFACE55 // There is no code in this area
21 #define TIMER_DIVISOR 11931 //~100Hz
25 extern void APStartup(); // 16-bit AP startup code
26 extern Uint GetRIP(); // start.asm
27 extern Uint64 gInitialPML4[512]; // start.asm
28 extern void gInitialKernelStack;
29 extern tSpinlock glThreadListLock;
32 extern int giTotalTickets;
33 extern int giNumActiveThreads;
34 extern tThread gThreadZero;
35 extern tThread *gActiveThreads;
36 extern tThread *gSleepingThreads;
37 extern tThread *gDeleteThreads;
38 extern tThread *Threads_GetNextToRun(int CPU);
39 extern void Threads_Dump();
40 extern tThread *Threads_CloneTCB(Uint *Err, Uint Flags);
41 extern void Proc_AlterUserReturnAddr();
44 void ArchThreads_Init();
46 void MP_StartAP(int CPU);
47 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
50 tThread *Proc_GetCurThread();
51 void Proc_ChangeStack();
52 int Proc_Clone(Uint *Err, Uint Flags);
53 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP);
54 void Proc_CallFaultHandler(tThread *Thread);
55 void Proc_Scheduler();
58 // --- Multiprocessing ---
60 volatile int giNumInitingCPUs = 0;
61 tMPInfo *gMPFloatPtr = NULL;
62 tAPIC *gpMP_LocalAPIC = NULL;
63 Uint8 gaAPIC_to_CPU[256] = {0};
64 tCPU gaCPUs[MAX_CPUS];
66 tThread *gCurrentThread = NULL;
70 // --- Error Recovery ---
71 Uint32 gaDoubleFaultStack[1024];
75 * \fn void ArchThreads_Init()
76 * \brief Starts the process scheduler
78 void ArchThreads_Init()
88 // -- Initialise Multiprocessing
89 // Find MP Floating Table
90 // - EBDA/Last 1Kib (640KiB)
91 for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
92 if( *(Uint*)(pos) == MPPTR_IDENT ) {
93 Log("Possible %p", pos);
94 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
95 gMPFloatPtr = (void*)pos;
99 // - Last KiB (512KiB base mem)
101 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
102 if( *(Uint*)(pos) == MPPTR_IDENT ) {
103 Log("Possible %p", pos);
104 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
105 gMPFloatPtr = (void*)pos;
112 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
113 if( *(Uint*)(pos) == MPPTR_IDENT ) {
114 Log("Possible %p", pos);
115 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
116 gMPFloatPtr = (void*)pos;
122 // If the MP Table Exists, parse it
127 Log("gMPFloatPtr = %p", gMPFloatPtr);
128 Log("*gMPFloatPtr = {");
129 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
130 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
131 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
132 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
133 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
134 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
135 gMPFloatPtr->Features[0], gMPFloatPtr->Features[1],
136 gMPFloatPtr->Features[2], gMPFloatPtr->Features[3],
137 gMPFloatPtr->Features[4]
141 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
142 Log("mptable = %p", mptable);
144 Log("\t.Sig = 0x%08x", mptable->Sig);
145 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
146 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
147 Log("\t.Checksum = 0x%02x", mptable->Checksum);
148 Log("\t.OEMID = '%8c'", mptable->OemID);
149 Log("\t.ProductID = '%8c'", mptable->ProductID);
150 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
151 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
152 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
153 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
154 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
155 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
158 gpMP_LocalAPIC = (void*)MM_MapHWPage(mptable->LocalAPICMemMap, 1);
160 ents = mptable->Entries;
163 for( i = 0; i < mptable->EntryCount; i ++ )
170 Log("%i: Processor", i);
171 Log("\t.APICID = %i", ents->Proc.APICID);
172 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
173 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
174 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
175 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
178 if( !(ents->Proc.CPUFlags & 1) ) {
183 // Check if there is too many processors
184 if(giNumCPUs >= MAX_CPUS) {
185 giNumCPUs ++; // If `giNumCPUs` > MAX_CPUS later, it will be clipped
189 // Initialise CPU Info
190 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
191 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
192 gaCPUs[giNumCPUs].State = 0;
196 if( !(ents->Proc.CPUFlags & 2) )
198 MP_StartAP( giNumCPUs-1 );
205 Log("\t.ID = %i", ents->Bus.ID);
206 Log("\t.TypeString = '%6c'", ents->Bus.TypeString);
210 Log("%i: I/O APIC", i);
211 Log("\t.ID = %i", ents->IOAPIC.ID);
212 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
213 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
214 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
216 case 3: // I/O Interrupt Assignment
218 Log("%i: I/O Interrupt Assignment", i);
219 Log("\t.IntType = %i", ents->IOInt.IntType);
220 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
221 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
222 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
223 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
224 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
226 case 4: // Local Interrupt Assignment
228 Log("%i: Local Interrupt Assignment", i);
229 Log("\t.IntType = %i", ents->LocalInt.IntType);
230 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
231 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
232 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
233 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
234 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
237 Log("%i: Unknown (%i)", i, ents->Type);
240 ents = (void*)( (Uint)ents + entSize );
243 if( giNumCPUs > MAX_CPUS ) {
244 Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
245 giNumCPUs = MAX_CPUS;
248 while( giNumInitingCPUs )
249 MM_FinishVirtualInit();
251 Panic("Uh oh... MP Table Parsing is unimplemented\n");
254 Log("No MP Table was found, assuming uniprocessor\n");
261 MM_FinishVirtualInit();
265 // Initialise Normal TSS(s)
266 for(pos=0;pos<giNumCPUs;pos++)
271 gTSSs[pos].RSP0 = 0; // Set properly by scheduler
272 gGDT[6+pos*2].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
273 gGDT[6+pos*2].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
274 gGDT[6+pos*2].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
275 gGDT[6+pos*2+1].DWord[0] = ((Uint)(&gTSSs[pos])) >> 32;
278 for(pos=0;pos<giNumCPUs;pos++) {
280 __asm__ __volatile__ ("ltr %%ax"::"a"(0x30+pos*8));
286 gaCPUs[0].Current = &gThreadZero;
288 gCurrentThread = &gThreadZero;
291 gThreadZero.MemState.CR3 = (Uint)gInitialPML4 - KERNEL_BASE;
293 // Set timer frequency
294 outb(0x43, 0x34); // Set Channel 0, Low/High, Rate Generator
295 outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
296 outb(0x40, (TIMER_DIVISOR>>8)&0xFF); // High Byte
298 // Create Per-Process Data Block
299 MM_Allocate(MM_PPD_CFG);
306 void MP_StartAP(int CPU)
308 Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
309 // Set location of AP startup code and mark for a warm restart
310 *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0);
311 *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
312 outb(0x70, 0x0F); outb(0x71, 0x0A); // Warm Reset
313 MP_SendIPI(gaCPUs[CPU].APICID, 0, 5);
317 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
319 Uint32 addr = (Uint)gpMP_LocalAPIC + 0x300;
323 val = (Uint)APICID << 24;
324 Log("*%p = 0x%08x", addr+0x10, val);
325 *(Uint32*)(addr+0x10) = val;
327 val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
328 Log("*%p = 0x%08x", addr, val);
329 *(Uint32*)addr = val;
334 * \fn void Proc_Start()
335 * \brief Start process scheduler
339 // Start Interrupts (and hence scheduler)
340 __asm__ __volatile__("sti");
344 * \fn tThread *Proc_GetCurThread()
345 * \brief Gets the current thread
347 tThread *Proc_GetCurThread()
350 return gaCPUs[ gaAPIC_to_CPU[gpMP_LocalAPIC->ID.Val&0xFF] ].Current;
352 return gCurrentThread;
357 * \fn void Proc_ChangeStack()
358 * \brief Swaps the current stack for a new one (in the proper stack reigon)
360 void Proc_ChangeStack()
363 Uint tmp_rbp, old_rsp;
364 Uint curBase, newBase;
366 __asm__ __volatile__ ("mov %%rsp, %0":"=r"(rsp));
367 __asm__ __volatile__ ("mov %%rbp, %0":"=r"(rbp));
372 newBase = MM_NewKStack();
375 Panic("What the?? Unable to allocate space for initial kernel stack");
379 curBase = (Uint)&gInitialKernelStack;
381 LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
383 // Get ESP as a used size
385 LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - rsp), (void*)(curBase - rsp), rsp );
387 memcpy( (void*)(newBase - rsp), (void*)(curBase - rsp), rsp );
388 // Get ESP as an offset in the new stack
391 rbp = newBase - (curBase - rbp);
393 // Repair EBPs & Stack Addresses
394 // Catches arguments also, but may trash stack-address-like values
395 for(tmp_rbp = rsp; tmp_rbp < newBase; tmp_rbp += 4)
397 if(old_rsp < *(Uint*)tmp_rbp && *(Uint*)tmp_rbp < curBase)
398 *(Uint*)tmp_rbp += newBase - curBase;
401 Proc_GetCurThread()->KernelStack = newBase;
403 __asm__ __volatile__ ("mov %0, %%rsp"::"r"(rsp));
404 __asm__ __volatile__ ("mov %0, %%rbp"::"r"(rbp));
408 * \fn int Proc_Clone(Uint *Err, Uint Flags)
409 * \brief Clone the current process
411 int Proc_Clone(Uint *Err, Uint Flags)
414 tThread *cur = Proc_GetCurThread();
417 __asm__ __volatile__ ("mov %%rsp, %0": "=r"(rsp));
418 __asm__ __volatile__ ("mov %%rbp, %0": "=r"(rbp));
420 newThread = Threads_CloneTCB(Err, Flags);
421 if(!newThread) return -1;
423 // Initialise Memory Space (New Addr space or kernel stack)
424 if(Flags & CLONE_VM) {
425 newThread->MemState.CR3 = MM_Clone();
426 newThread->KernelStack = cur->KernelStack;
428 Uint tmp_rbp, old_rsp = rsp;
431 newThread->MemState.CR3 = cur->MemState.CR3;
434 newThread->KernelStack = MM_NewKStack();
436 if(newThread->KernelStack == 0) {
441 // Get ESP as a used size
442 rsp = cur->KernelStack - rsp;
445 (void*)(newThread->KernelStack - rsp),
446 (void*)(cur->KernelStack - rsp),
449 // Get ESP as an offset in the new stack
450 rsp = newThread->KernelStack - rsp;
452 rbp = newThread->KernelStack - (cur->KernelStack - rbp);
454 // Repair EBPs & Stack Addresses
455 // Catches arguments also, but may trash stack-address-like values
456 for(tmp_rbp = rsp; tmp_rbp < newThread->KernelStack; tmp_rbp += 4)
458 if(old_rsp < *(Uint*)tmp_rbp && *(Uint*)tmp_rbp < cur->KernelStack)
459 *(Uint*)tmp_rbp += newThread->KernelStack - cur->KernelStack;
463 // Save core machine state
464 newThread->SavedState.RSP = rsp;
465 newThread->SavedState.RBP = rbp;
467 if(rip == SWITCH_MAGIC) {
468 outb(0x20, 0x20); // ACK Timer and return as child
473 newThread->SavedState.RIP = rip;
475 // Lock list and add to active
476 Threads_AddActive(newThread);
478 return newThread->TID;
482 * \fn int Proc_SpawnWorker()
483 * \brief Spawns a new worker thread
485 int Proc_SpawnWorker()
490 cur = Proc_GetCurThread();
493 new = malloc( sizeof(tThread) );
495 Warning("Proc_SpawnWorker - Out of heap space!\n");
498 memcpy(new, &gThreadZero, sizeof(tThread));
500 new->TID = giNextTID++;
501 // Create a new worker stack (in PID0's address space)
502 // The stack is relocated by this code
503 new->KernelStack = MM_NewWorkerStack();
505 // Get ESP and EBP based in the new stack
506 __asm__ __volatile__ ("mov %%rsp, %0": "=r"(rsp));
507 __asm__ __volatile__ ("mov %%rbp, %0": "=r"(rbp));
508 rsp = new->KernelStack - (cur->KernelStack - rsp);
509 rbp = new->KernelStack - (cur->KernelStack - rbp);
511 // Save core machine state
512 new->SavedState.RSP = rsp;
513 new->SavedState.RBP = rbp;
515 if(rip == SWITCH_MAGIC) {
516 outb(0x20, 0x20); // ACK Timer and return as child
521 new->SavedState.RIP = rip;
523 new->Status = THREAD_STAT_ACTIVE;
524 Threads_AddActive( new );
530 * \fn Uint Proc_MakeUserStack()
531 * \brief Creates a new user stack
533 Uint Proc_MakeUserStack()
536 Uint base = USER_STACK_TOP - USER_STACK_SZ;
538 // Check Prospective Space
539 for( i = USER_STACK_SZ >> 12; i--; )
540 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
543 if(i != -1) return 0;
545 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
546 for( i = 0; i < USER_STACK_SZ/4069; i++ )
547 MM_Allocate( base + (i<<12) );
549 return base + USER_STACK_SZ;
554 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
555 * \brief Starts a user task
557 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
559 Uint *stack = (void*)Proc_MakeUserStack();
564 LOG("stack = 0x%x", stack);
567 stack = (void*)( (Uint)stack - DataSize );
568 memcpy( stack, ArgV, DataSize );
570 // Adjust Arguments and environment
571 delta = (Uint)stack - (Uint)ArgV;
572 ArgV = (char**)stack;
573 for( i = 0; ArgV[i]; i++ ) ArgV[i] += delta;
576 for( i = 0; EnvP[i]; i++ ) EnvP[i] += delta;
578 // User Mode Segments
579 ss = 0x23; cs = 0x1B;
582 *--stack = (Uint)EnvP;
583 *--stack = (Uint)ArgV;
584 *--stack = (Uint)ArgC;
587 *--stack = 0; // Return Address
589 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
592 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
594 Uint *stack = (void*)Stack;
595 *--stack = SS; //Stack Segment
596 *--stack = Stack; //Stack Pointer
597 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
598 *--stack = CS; //Code Segment
601 *--stack = 0xAAAAAAAA; // eax
602 *--stack = 0xCCCCCCCC; // ecx
603 *--stack = 0xDDDDDDDD; // edx
604 *--stack = 0xBBBBBBBB; // ebx
605 *--stack = 0xD1D1D1D1; // edi
606 *--stack = 0x54545454; // rsp - NOT POPED
607 *--stack = 0x51515151; // esi
608 *--stack = 0xB4B4B4B4; // rbp
612 __asm__ __volatile__ (
613 "mov %%rax,%%rsp;\n\t" // Set stack pointer
614 "iret;\n\t" : : "a" (stack));
619 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
620 * \brief Demotes a process to a lower permission level
621 * \param Err Pointer to user's errno
622 * \param Dest New Permission Level
623 * \param Regs Pointer to user's register structure
625 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
627 int cpl = Regs->cs & 3;
629 if(Dest > 3 || Dest < 0) {
640 // Change the Segment Registers
641 Regs->cs = (((Dest+1)<<4) | Dest) - 8;
642 Regs->ss = ((Dest+1)<<4) | Dest;
643 // Check if the GP Segs are GDT, then change them
644 if(!(Regs->ds & 4)) Regs->ds = ((Dest+1)<<4) | Dest;
645 if(!(Regs->es & 4)) Regs->es = ((Dest+1)<<4) | Dest;
646 if(!(Regs->fs & 4)) Regs->fs = ((Dest+1)<<4) | Dest;
647 if(!(Regs->gs & 4)) Regs->gs = ((Dest+1)<<4) | Dest;
653 * \brief Calls a signal handler in user mode
654 * \note Used for signals
656 void Proc_CallFaultHandler(tThread *Thread)
658 // Rewinds the stack and calls the user function
660 __asm__ __volatile__ ("mov %0, %%rbp;\n\tcall Proc_AlterUserReturnAddr" :: "r"(Thread->FaultHandler));
665 * \fn void Proc_Scheduler(int CPU)
666 * \brief Swap current thread and clears dead threads
668 void Proc_Scheduler(int CPU)
673 // If the spinlock is set, let it complete
674 if(IS_LOCKED(&glThreadListLock)) return;
676 // Clear Delete Queue
677 while(gDeleteThreads)
679 thread = gDeleteThreads->Next;
680 if(gDeleteThreads->IsLocked) { // Only free if structure is unused
681 gDeleteThreads->Status = THREAD_STAT_NULL;
682 free( gDeleteThreads );
684 gDeleteThreads = thread;
687 // Check if there is any tasks running
688 if(giNumActiveThreads == 0) {
689 Log("No Active threads, sleeping");
690 __asm__ __volatile__ ("hlt");
694 // Get current thread
696 thread = gaCPUs[CPU].Current;
698 thread = gCurrentThread;
701 // Reduce remaining quantum and continue timeslice if non-zero
702 if(thread->Remaining--) return;
703 // Reset quantum for next call
704 thread->Remaining = thread->Quantum;
707 __asm__ __volatile__ ("mov %%rsp, %0":"=r"(rsp));
708 __asm__ __volatile__ ("mov %%rbp, %0":"=r"(rbp));
710 if(rip == SWITCH_MAGIC) return; // Check if a switch happened
712 // Save machine state
713 thread->SavedState.RSP = rsp;
714 thread->SavedState.RBP = rbp;
715 thread->SavedState.RIP = rip;
718 thread = Threads_GetNextToRun(CPU);
722 Warning("Hmm... Threads_GetNextToRun returned NULL, I don't think this should happen.\n");
726 #if DEBUG_TRACE_SWITCH
727 Log("Switching to task %i, CR3 = 0x%x, RIP = %p",
729 thread->MemState.CR3,
730 thread->SavedState.RIP
734 // Set current thread
736 gaCPUs[CPU].Current = thread;
738 gCurrentThread = thread;
741 // Update Kernel Stack pointer
742 gTSSs[CPU].RSP0 = thread->KernelStack-4;
746 # error "Todo: Implement PAE Address space switching"
748 __asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
752 if(thread->SavedState.RSP > 0xC0000000
753 && thread->SavedState.RSP < thread->KernelStack-0x2000) {
754 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
759 __asm__ __volatile__ (
760 "mov %1, %%rsp\n\t" // Restore RSP
761 "mov %2, %%rbp\n\t" // and RBP
762 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
763 "a"(SWITCH_MAGIC), "b"(thread->SavedState.RSP),
764 "d"(thread->SavedState.RBP), "c"(thread->SavedState.RIP)
766 for(;;); // Shouldn't reach here
770 EXPORT(Proc_SpawnWorker);