xref: /reactos/ntoskrnl/ke/i386/kiinit.c (revision 019f21ee)
1 /*
2  * PROJECT:         ReactOS Kernel
3  * LICENSE:         GPL - See COPYING in the top level directory
4  * FILE:            ntoskrnl/ke/i386/kiinit.c
5  * PURPOSE:         Kernel Initialization for x86 CPUs
6  * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
7  */
8 
9 /* INCLUDES *****************************************************************/
10 
11 #include <ntoskrnl.h>
12 #define NDEBUG
13 #include <debug.h>
14 #include "internal/i386/trap_x.h"
15 
16 /* GLOBALS *******************************************************************/
17 
18 /* Boot and double-fault/NMI/DPC stack */
19 UCHAR DECLSPEC_ALIGN(PAGE_SIZE) P0BootStackData[KERNEL_STACK_SIZE] = {0};
20 UCHAR DECLSPEC_ALIGN(PAGE_SIZE) KiDoubleFaultStackData[KERNEL_STACK_SIZE] = {0};
21 ULONG_PTR P0BootStack = (ULONG_PTR)&P0BootStackData[KERNEL_STACK_SIZE];
22 ULONG_PTR KiDoubleFaultStack = (ULONG_PTR)&KiDoubleFaultStackData[KERNEL_STACK_SIZE];
23 
24 /* Spinlocks used only on X86 */
25 KSPIN_LOCK KiFreezeExecutionLock;
26 KSPIN_LOCK Ki486CompatibilityLock;
27 
28 /* Perf */
29 ULONG ProcessCount;
30 ULONGLONG BootCycles, BootCyclesEnd;
31 
32 /* FUNCTIONS *****************************************************************/
33 
34 INIT_FUNCTION
35 VOID
36 NTAPI
37 KiInitMachineDependent(VOID)
38 {
39     ULONG CpuCount;
40     BOOLEAN FbCaching = FALSE;
41     NTSTATUS Status;
42     ULONG ReturnLength;
43     ULONG i, Affinity, Sample = 0;
44     PFX_SAVE_AREA FxSaveArea;
45     ULONG MXCsrMask = 0xFFBF;
46     CPU_INFO CpuInfo;
47     KI_SAMPLE_MAP Samples[10];
48     PKI_SAMPLE_MAP CurrentSample = Samples;
49     LARGE_IDENTITY_MAP IdentityMap;
50 
51     /* Check for large page support */
52     if (KeFeatureBits & KF_LARGE_PAGE)
53     {
54         /* Do an IPI to enable it on all CPUs */
55         if (Ki386CreateIdentityMap(&IdentityMap, Ki386EnableCurrentLargePage, 2))
56             KeIpiGenericCall(Ki386EnableTargetLargePage, (ULONG_PTR)&IdentityMap);
57 
58         /* Free the pages allocated for identity map */
59         Ki386FreeIdentityMap(&IdentityMap);
60     }
61 
62     /* Check for global page support */
63     if (KeFeatureBits & KF_GLOBAL_PAGE)
64     {
65         /* Do an IPI to enable it on all CPUs */
66         CpuCount = KeNumberProcessors;
67         KeIpiGenericCall(Ki386EnableGlobalPage, (ULONG_PTR)&CpuCount);
68     }
69 
70     /* Check for PAT and/or MTRR support */
71     if (KeFeatureBits & (KF_PAT | KF_MTRR))
72     {
73         /* Query the HAL to make sure we can use it */
74         Status = HalQuerySystemInformation(HalFrameBufferCachingInformation,
75                                            sizeof(BOOLEAN),
76                                            &FbCaching,
77                                            &ReturnLength);
78         if ((NT_SUCCESS(Status)) && (FbCaching))
79         {
80             /* We can't, disable it */
81             KeFeatureBits &= ~(KF_PAT | KF_MTRR);
82         }
83     }
84 
85     /* Check for PAT support and enable it */
86     if (KeFeatureBits & KF_PAT) KiInitializePAT();
87 
88     /* Assume no errata for now */
89     SharedUserData->ProcessorFeatures[PF_FLOATING_POINT_PRECISION_ERRATA] = 0;
90 
91     /* Check if we have an NPX */
92     if (KeI386NpxPresent)
93     {
94         /* Loop every CPU */
95         i = KeActiveProcessors;
96         for (Affinity = 1; i; Affinity <<= 1)
97         {
98             /* Check if this is part of the set */
99             if (i & Affinity)
100             {
101                 /* Run on this CPU */
102                 i &= ~Affinity;
103                 KeSetSystemAffinityThread(Affinity);
104 
105                 /* Detect FPU errata */
106                 if (KiIsNpxErrataPresent())
107                 {
108                     /* Disable NPX support */
109                     KeI386NpxPresent = FALSE;
110                     SharedUserData->
111                         ProcessorFeatures[PF_FLOATING_POINT_PRECISION_ERRATA] =
112                         TRUE;
113                     break;
114                 }
115             }
116         }
117     }
118 
119     /* If there's no NPX, then we're emulating the FPU */
120     SharedUserData->ProcessorFeatures[PF_FLOATING_POINT_EMULATED] =
121         !KeI386NpxPresent;
122 
123     /* Check if there's no NPX, so that we can disable associated features */
124     if (!KeI386NpxPresent)
125     {
126         /* Remove NPX-related bits */
127         KeFeatureBits &= ~(KF_XMMI64 | KF_XMMI | KF_FXSR | KF_MMX);
128 
129         /* Disable kernel flags */
130         KeI386FxsrPresent = KeI386XMMIPresent = FALSE;
131 
132         /* Disable processor features that might've been set until now */
133         SharedUserData->ProcessorFeatures[PF_FLOATING_POINT_PRECISION_ERRATA] =
134         SharedUserData->ProcessorFeatures[PF_XMMI64_INSTRUCTIONS_AVAILABLE]   =
135         SharedUserData->ProcessorFeatures[PF_XMMI_INSTRUCTIONS_AVAILABLE]     =
136         SharedUserData->ProcessorFeatures[PF_3DNOW_INSTRUCTIONS_AVAILABLE]    =
137         SharedUserData->ProcessorFeatures[PF_MMX_INSTRUCTIONS_AVAILABLE] = 0;
138     }
139 
140     /* Check for CR4 support */
141     if (KeFeatureBits & KF_CR4)
142     {
143         /* Do an IPI call to enable the Debug Exceptions */
144         CpuCount = KeNumberProcessors;
145         KeIpiGenericCall(Ki386EnableDE, (ULONG_PTR)&CpuCount);
146     }
147 
148     /* Check if FXSR was found */
149     if (KeFeatureBits & KF_FXSR)
150     {
151         /* Do an IPI call to enable the FXSR */
152         CpuCount = KeNumberProcessors;
153         KeIpiGenericCall(Ki386EnableFxsr, (ULONG_PTR)&CpuCount);
154 
155         /* Check if XMM was found too */
156         if (KeFeatureBits & KF_XMMI)
157         {
158             /* Do an IPI call to enable XMMI exceptions */
159             CpuCount = KeNumberProcessors;
160             KeIpiGenericCall(Ki386EnableXMMIExceptions, (ULONG_PTR)&CpuCount);
161 
162             /* FIXME: Implement and enable XMM Page Zeroing for Mm */
163 
164             /* Patch the RtlPrefetchMemoryNonTemporal routine to enable it */
165             *(PCHAR)RtlPrefetchMemoryNonTemporal = 0x90; // NOP
166         }
167     }
168 
169     /* Check for, and enable SYSENTER support */
170     KiRestoreFastSyscallReturnState();
171 
172     /* Loop every CPU */
173     i = KeActiveProcessors;
174     for (Affinity = 1; i; Affinity <<= 1)
175     {
176         /* Check if this is part of the set */
177         if (i & Affinity)
178         {
179             /* Run on this CPU */
180             i &= ~Affinity;
181             KeSetSystemAffinityThread(Affinity);
182 
183             /* Reset MHz to 0 for this CPU */
184             KeGetCurrentPrcb()->MHz = 0;
185 
186             /* Check if we can use RDTSC */
187             if (KeFeatureBits & KF_RDTSC)
188             {
189                 /* Start sampling loop */
190                 for (;;)
191                 {
192                     /* Do a dummy CPUID to start the sample */
193                     KiCpuId(&CpuInfo, 0);
194 
195                     /* Fill out the starting data */
196                     CurrentSample->PerfStart = KeQueryPerformanceCounter(NULL);
197                     CurrentSample->TSCStart = __rdtsc();
198                     CurrentSample->PerfFreq.QuadPart = -50000;
199 
200                     /* Sleep for this sample */
201                     KeDelayExecutionThread(KernelMode,
202                                            FALSE,
203                                            &CurrentSample->PerfFreq);
204 
205                     /* Do another dummy CPUID */
206                     KiCpuId(&CpuInfo, 0);
207 
208                     /* Fill out the ending data */
209                     CurrentSample->PerfEnd =
210                         KeQueryPerformanceCounter(&CurrentSample->PerfFreq);
211                     CurrentSample->TSCEnd = __rdtsc();
212 
213                     /* Calculate the differences */
214                     CurrentSample->PerfDelta = CurrentSample->PerfEnd.QuadPart -
215                                                CurrentSample->PerfStart.QuadPart;
216                     CurrentSample->TSCDelta = CurrentSample->TSCEnd -
217                                               CurrentSample->TSCStart;
218 
219                     /* Compute CPU Speed */
220                     CurrentSample->MHz = (ULONG)((CurrentSample->TSCDelta *
221                                                   CurrentSample->
222                                                   PerfFreq.QuadPart + 500000) /
223                                                  (CurrentSample->PerfDelta *
224                                                   1000000));
225 
226                     /* Check if this isn't the first sample */
227                     if (Sample)
228                     {
229                         /* Check if we got a good precision within 1MHz */
230                         if ((CurrentSample->MHz == CurrentSample[-1].MHz) ||
231                             (CurrentSample->MHz == CurrentSample[-1].MHz + 1) ||
232                             (CurrentSample->MHz == CurrentSample[-1].MHz - 1))
233                         {
234                             /* We did, stop sampling */
235                             break;
236                         }
237                     }
238 
239                     /* Move on */
240                     CurrentSample++;
241                     Sample++;
242 
243                     if (Sample == RTL_NUMBER_OF(Samples))
244                     {
245                         /* No luck. Average the samples and be done */
246                         ULONG TotalMHz = 0;
247                         while (Sample--)
248                         {
249                             TotalMHz += Samples[Sample].MHz;
250                         }
251                         CurrentSample[-1].MHz = TotalMHz / RTL_NUMBER_OF(Samples);
252                         DPRINT1("Sampling CPU frequency failed. Using average of %lu MHz\n", CurrentSample[-1].MHz);
253                         break;
254                     }
255                 }
256 
257                 /* Save the CPU Speed */
258                 KeGetCurrentPrcb()->MHz = CurrentSample[-1].MHz;
259             }
260 
261             /* Check if we have MTRR */
262             if (KeFeatureBits & KF_MTRR)
263             {
264                 /* Then manually initialize MTRR for the CPU */
265                 KiInitializeMTRR(i ? FALSE : TRUE);
266             }
267 
268             /* Check if we have AMD MTRR and initialize it for the CPU */
269             if (KeFeatureBits & KF_AMDK6MTRR) KiAmdK6InitializeMTRR();
270 
271             /* Check if this is a buggy Pentium and apply the fixup if so */
272             if (KiI386PentiumLockErrataPresent) KiI386PentiumLockErrataFixup();
273 
274             /* Check if the CPU supports FXSR */
275             if (KeFeatureBits & KF_FXSR)
276             {
277                 /* Get the current thread NPX state */
278                 FxSaveArea = KiGetThreadNpxArea(KeGetCurrentThread());
279 
280                 /* Clear initial MXCsr mask */
281                 FxSaveArea->U.FxArea.MXCsrMask = 0;
282 
283                 /* Save the current NPX State */
284                 Ke386SaveFpuState(FxSaveArea);
285 
286                 /* Check if the current mask doesn't match the reserved bits */
287                 if (FxSaveArea->U.FxArea.MXCsrMask != 0)
288                 {
289                     /* Then use whatever it's holding */
290                     MXCsrMask = FxSaveArea->U.FxArea.MXCsrMask;
291                 }
292 
293                 /* Check if nobody set the kernel-wide mask */
294                 if (!KiMXCsrMask)
295                 {
296                     /* Then use the one we calculated above */
297                     KiMXCsrMask = MXCsrMask;
298                 }
299                 else
300                 {
301                     /* Was it set to the same value we found now? */
302                     if (KiMXCsrMask != MXCsrMask)
303                     {
304                         /* No, something is definitely wrong */
305                         KeBugCheckEx(MULTIPROCESSOR_CONFIGURATION_NOT_SUPPORTED,
306                                      KF_FXSR,
307                                      KiMXCsrMask,
308                                      MXCsrMask,
309                                      0);
310                     }
311                 }
312 
313                 /* Now set the kernel mask */
314                 KiMXCsrMask &= MXCsrMask;
315             }
316         }
317     }
318 
319     /* Return affinity back to where it was */
320     KeRevertToUserAffinityThread();
321 
322     /* NT allows limiting the duration of an ISR with a registry key */
323     if (KiTimeLimitIsrMicroseconds)
324     {
325         /* FIXME: TODO */
326         DPRINT1("ISR Time Limit not yet supported\n");
327     }
328 
329     /* Set CR0 features based on detected CPU */
330     KiSetCR0Bits();
331 }
332 
333 INIT_FUNCTION
334 VOID
335 NTAPI
336 KiInitializePcr(IN ULONG ProcessorNumber,
337                 IN PKIPCR Pcr,
338                 IN PKIDTENTRY Idt,
339                 IN PKGDTENTRY Gdt,
340                 IN PKTSS Tss,
341                 IN PKTHREAD IdleThread,
342                 IN PVOID DpcStack)
343 {
344     /* Setup the TIB */
345     Pcr->NtTib.ExceptionList = EXCEPTION_CHAIN_END;
346     Pcr->NtTib.StackBase = 0;
347     Pcr->NtTib.StackLimit = 0;
348     Pcr->NtTib.Self = NULL;
349 
350     /* Set the Current Thread */
351     Pcr->PrcbData.CurrentThread = IdleThread;
352 
353     /* Set pointers to ourselves */
354     Pcr->SelfPcr = (PKPCR)Pcr;
355     Pcr->Prcb = &Pcr->PrcbData;
356 
357     /* Set the PCR Version */
358     Pcr->MajorVersion = PCR_MAJOR_VERSION;
359     Pcr->MinorVersion = PCR_MINOR_VERSION;
360 
361     /* Set the PCRB Version */
362     Pcr->PrcbData.MajorVersion = 1;
363     Pcr->PrcbData.MinorVersion = 1;
364 
365     /* Set the Build Type */
366     Pcr->PrcbData.BuildType = 0;
367 #ifndef CONFIG_SMP
368     Pcr->PrcbData.BuildType |= PRCB_BUILD_UNIPROCESSOR;
369 #endif
370 #if DBG
371     Pcr->PrcbData.BuildType |= PRCB_BUILD_DEBUG;
372 #endif
373 
374     /* Set the Processor Number and current Processor Mask */
375     Pcr->PrcbData.Number = (UCHAR)ProcessorNumber;
376     Pcr->PrcbData.SetMember = 1 << ProcessorNumber;
377 
378     /* Set the PRCB for this Processor */
379     KiProcessorBlock[ProcessorNumber] = Pcr->Prcb;
380 
381     /* Start us out at PASSIVE_LEVEL */
382     Pcr->Irql = PASSIVE_LEVEL;
383 
384     /* Set the GDI, IDT, TSS and DPC Stack */
385     Pcr->GDT = (PVOID)Gdt;
386     Pcr->IDT = Idt;
387     Pcr->TSS = Tss;
388     Pcr->TssCopy = Tss;
389     Pcr->PrcbData.DpcStack = DpcStack;
390 
391     /* Setup the processor set */
392     Pcr->PrcbData.MultiThreadProcessorSet = Pcr->PrcbData.SetMember;
393 }
394 
395 INIT_FUNCTION
396 VOID
397 NTAPI
398 KiInitializeKernel(IN PKPROCESS InitProcess,
399                    IN PKTHREAD InitThread,
400                    IN PVOID IdleStack,
401                    IN PKPRCB Prcb,
402                    IN CCHAR Number,
403                    IN PLOADER_PARAMETER_BLOCK LoaderBlock)
404 {
405     BOOLEAN NpxPresent;
406     ULONG FeatureBits;
407     ULONG PageDirectory[2];
408     PVOID DpcStack;
409     ULONG Vendor[3];
410     KIRQL DummyIrql;
411 
412     /* Detect and set the CPU Type */
413     KiSetProcessorType();
414 
415     /* Check if an FPU is present */
416     NpxPresent = KiIsNpxPresent();
417 
418     /* Initialize the Power Management Support for this PRCB */
419     PoInitializePrcb(Prcb);
420 
421     /* Bugcheck if this is a 386 CPU */
422     if (Prcb->CpuType == 3) KeBugCheckEx(UNSUPPORTED_PROCESSOR, 0x386, 0, 0, 0);
423 
424     /* Get the processor features for the CPU */
425     FeatureBits = KiGetFeatureBits();
426 
427     /* Set the default NX policy (opt-in) */
428     SharedUserData->NXSupportPolicy = NX_SUPPORT_POLICY_OPTIN;
429 
430     /* Check if NPX is always on */
431     if (strstr(KeLoaderBlock->LoadOptions, "NOEXECUTE=ALWAYSON"))
432     {
433         /* Set it always on */
434         SharedUserData->NXSupportPolicy = NX_SUPPORT_POLICY_ALWAYSON;
435         FeatureBits |= KF_NX_ENABLED;
436     }
437     else if (strstr(KeLoaderBlock->LoadOptions, "NOEXECUTE=OPTOUT"))
438     {
439         /* Set it in opt-out mode */
440         SharedUserData->NXSupportPolicy = NX_SUPPORT_POLICY_OPTOUT;
441         FeatureBits |= KF_NX_ENABLED;
442     }
443     else if ((strstr(KeLoaderBlock->LoadOptions, "NOEXECUTE=OPTIN")) ||
444              (strstr(KeLoaderBlock->LoadOptions, "NOEXECUTE")))
445     {
446         /* Set the feature bits */
447         FeatureBits |= KF_NX_ENABLED;
448     }
449     else if ((strstr(KeLoaderBlock->LoadOptions, "NOEXECUTE=ALWAYSOFF")) ||
450              (strstr(KeLoaderBlock->LoadOptions, "EXECUTE")))
451     {
452         /* Set disabled mode */
453         SharedUserData->NXSupportPolicy = NX_SUPPORT_POLICY_ALWAYSOFF;
454         FeatureBits |= KF_NX_DISABLED;
455     }
456 
457     /* Save feature bits */
458     Prcb->FeatureBits = FeatureBits;
459 
460     /* Save CPU state */
461     KiSaveProcessorControlState(&Prcb->ProcessorState);
462 
463     /* Get cache line information for this CPU */
464     KiGetCacheInformation();
465 
466     /* Initialize spinlocks and DPC data */
467     KiInitSpinLocks(Prcb, Number);
468 
469     /* Check if this is the Boot CPU */
470     if (!Number)
471     {
472         /* Set Node Data */
473         KeNodeBlock[0] = &KiNode0;
474         Prcb->ParentNode = KeNodeBlock[0];
475         KeNodeBlock[0]->ProcessorMask = Prcb->SetMember;
476 
477         /* Set boot-level flags */
478         KeI386NpxPresent = NpxPresent;
479         KeI386CpuType = Prcb->CpuType;
480         KeI386CpuStep = Prcb->CpuStep;
481         KeProcessorArchitecture = PROCESSOR_ARCHITECTURE_INTEL;
482         KeProcessorLevel = (USHORT)Prcb->CpuType;
483         if (Prcb->CpuID) KeProcessorRevision = Prcb->CpuStep;
484         KeFeatureBits = FeatureBits;
485         KeI386FxsrPresent = (KeFeatureBits & KF_FXSR) ? TRUE : FALSE;
486         KeI386XMMIPresent = (KeFeatureBits & KF_XMMI) ? TRUE : FALSE;
487 
488         /* Detect 8-byte compare exchange support */
489         if (!(KeFeatureBits & KF_CMPXCHG8B))
490         {
491             /* Copy the vendor string */
492             RtlCopyMemory(Vendor, Prcb->VendorString, sizeof(Vendor));
493 
494             /* Bugcheck the system. Windows *requires* this */
495             KeBugCheckEx(UNSUPPORTED_PROCESSOR,
496                          (1 << 24 ) | (Prcb->CpuType << 16) | Prcb->CpuStep,
497                          Vendor[0],
498                          Vendor[1],
499                          Vendor[2]);
500         }
501 
502         /* Set the current MP Master KPRCB to the Boot PRCB */
503         Prcb->MultiThreadSetMaster = Prcb;
504 
505         /* Lower to APC_LEVEL */
506         KeLowerIrql(APC_LEVEL);
507 
508         /* Initialize some spinlocks */
509         KeInitializeSpinLock(&KiFreezeExecutionLock);
510         KeInitializeSpinLock(&Ki486CompatibilityLock);
511 
512         /* Initialize portable parts of the OS */
513         KiInitSystem();
514 
515         /* Initialize the Idle Process and the Process Listhead */
516         InitializeListHead(&KiProcessListHead);
517         PageDirectory[0] = 0;
518         PageDirectory[1] = 0;
519         KeInitializeProcess(InitProcess,
520                             0,
521                             0xFFFFFFFF,
522                             PageDirectory,
523                             FALSE);
524         InitProcess->QuantumReset = MAXCHAR;
525     }
526     else
527     {
528         /* FIXME */
529         DPRINT1("SMP Boot support not yet present\n");
530     }
531 
532     /* Setup the Idle Thread */
533     KeInitializeThread(InitProcess,
534                        InitThread,
535                        NULL,
536                        NULL,
537                        NULL,
538                        NULL,
539                        NULL,
540                        IdleStack);
541     InitThread->NextProcessor = Number;
542     InitThread->Priority = HIGH_PRIORITY;
543     InitThread->State = Running;
544     InitThread->Affinity = 1 << Number;
545     InitThread->WaitIrql = DISPATCH_LEVEL;
546     InitProcess->ActiveProcessors = 1 << Number;
547 
548     /* HACK for MmUpdatePageDir */
549     ((PETHREAD)InitThread)->ThreadsProcess = (PEPROCESS)InitProcess;
550 
551     /* Set basic CPU Features that user mode can read */
552     SharedUserData->ProcessorFeatures[PF_MMX_INSTRUCTIONS_AVAILABLE] =
553         (KeFeatureBits & KF_MMX) ? TRUE: FALSE;
554     SharedUserData->ProcessorFeatures[PF_COMPARE_EXCHANGE_DOUBLE] =
555         (KeFeatureBits & KF_CMPXCHG8B) ? TRUE: FALSE;
556     SharedUserData->ProcessorFeatures[PF_XMMI_INSTRUCTIONS_AVAILABLE] =
557         ((KeFeatureBits & KF_FXSR) && (KeFeatureBits & KF_XMMI)) ? TRUE: FALSE;
558     SharedUserData->ProcessorFeatures[PF_XMMI64_INSTRUCTIONS_AVAILABLE] =
559         ((KeFeatureBits & KF_FXSR) && (KeFeatureBits & KF_XMMI64)) ? TRUE: FALSE;
560     SharedUserData->ProcessorFeatures[PF_3DNOW_INSTRUCTIONS_AVAILABLE] =
561         (KeFeatureBits & KF_3DNOW) ? TRUE: FALSE;
562     SharedUserData->ProcessorFeatures[PF_RDTSC_INSTRUCTION_AVAILABLE] =
563         (KeFeatureBits & KF_RDTSC) ? TRUE: FALSE;
564 
565     /* Set up the thread-related fields in the PRCB */
566     Prcb->CurrentThread = InitThread;
567     Prcb->NextThread = NULL;
568     Prcb->IdleThread = InitThread;
569 
570     /* Initialize the Kernel Executive */
571     ExpInitializeExecutive(Number, LoaderBlock);
572 
573     /* Only do this on the boot CPU */
574     if (!Number)
575     {
576         /* Calculate the time reciprocal */
577         KiTimeIncrementReciprocal =
578             KiComputeReciprocal(KeMaximumIncrement,
579                                 &KiTimeIncrementShiftCount);
580 
581         /* Update DPC Values in case they got updated by the executive */
582         Prcb->MaximumDpcQueueDepth = KiMaximumDpcQueueDepth;
583         Prcb->MinimumDpcRate = KiMinimumDpcRate;
584         Prcb->AdjustDpcThreshold = KiAdjustDpcThreshold;
585 
586         /* Allocate the DPC Stack */
587         DpcStack = MmCreateKernelStack(FALSE, 0);
588         if (!DpcStack) KeBugCheckEx(NO_PAGES_AVAILABLE, 1, 0, 0, 0);
589         Prcb->DpcStack = DpcStack;
590 
591         /* Allocate the IOPM save area */
592         Ki386IopmSaveArea = ExAllocatePoolWithTag(PagedPool,
593                                                   IOPM_SIZE,
594                                                   '  eK');
595         if (!Ki386IopmSaveArea)
596         {
597             /* Bugcheck. We need this for V86/VDM support. */
598             KeBugCheckEx(NO_PAGES_AVAILABLE, 2, IOPM_SIZE, 0, 0);
599         }
600     }
601 
602     /* Raise to Dispatch */
603     KeRaiseIrql(DISPATCH_LEVEL, &DummyIrql);
604 
605     /* Set the Idle Priority to 0. This will jump into Phase 1 */
606     KeSetPriorityThread(InitThread, 0);
607 
608     /* If there's no thread scheduled, put this CPU in the Idle summary */
609     KiAcquirePrcbLock(Prcb);
610     if (!Prcb->NextThread) KiIdleSummary |= 1 << Number;
611     KiReleasePrcbLock(Prcb);
612 
613     /* Raise back to HIGH_LEVEL and clear the PRCB for the loader block */
614     KeRaiseIrql(HIGH_LEVEL, &DummyIrql);
615     LoaderBlock->Prcb = 0;
616 }
617 
618 INIT_FUNCTION
619 VOID
620 FASTCALL
621 KiGetMachineBootPointers(IN PKGDTENTRY *Gdt,
622                          IN PKIDTENTRY *Idt,
623                          IN PKIPCR *Pcr,
624                          IN PKTSS *Tss)
625 {
626     KDESCRIPTOR GdtDescriptor, IdtDescriptor;
627     KGDTENTRY TssSelector, PcrSelector;
628     USHORT Tr, Fs;
629 
630     /* Get GDT and IDT descriptors */
631     Ke386GetGlobalDescriptorTable(&GdtDescriptor.Limit);
632     __sidt(&IdtDescriptor.Limit);
633 
634     /* Save IDT and GDT */
635     *Gdt = (PKGDTENTRY)GdtDescriptor.Base;
636     *Idt = (PKIDTENTRY)IdtDescriptor.Base;
637 
638     /* Get TSS and FS Selectors */
639     Tr = Ke386GetTr();
640     Fs = Ke386GetFs();
641 
642     /* Get PCR Selector, mask it and get its GDT Entry */
643     PcrSelector = *(PKGDTENTRY)((ULONG_PTR)*Gdt + (Fs & ~RPL_MASK));
644 
645     /* Get the KPCR itself */
646     *Pcr = (PKIPCR)(ULONG_PTR)(PcrSelector.BaseLow |
647                                PcrSelector.HighWord.Bytes.BaseMid << 16 |
648                                PcrSelector.HighWord.Bytes.BaseHi << 24);
649 
650     /* Get TSS Selector, mask it and get its GDT Entry */
651     TssSelector = *(PKGDTENTRY)((ULONG_PTR)*Gdt + (Tr & ~RPL_MASK));
652 
653     /* Get the KTSS itself */
654     *Tss = (PKTSS)(ULONG_PTR)(TssSelector.BaseLow |
655                               TssSelector.HighWord.Bytes.BaseMid << 16 |
656                               TssSelector.HighWord.Bytes.BaseHi << 24);
657 }
658 
659 INIT_FUNCTION
660 VOID
661 NTAPI
662 KiSystemStartupBootStack(VOID)
663 {
664     PKTHREAD Thread;
665 
666     /* Initialize the kernel for the current CPU */
667     KiInitializeKernel(&KiInitialProcess.Pcb,
668                        (PKTHREAD)KeLoaderBlock->Thread,
669                        (PVOID)(KeLoaderBlock->KernelStack & ~3),
670                        (PKPRCB)__readfsdword(KPCR_PRCB),
671                        KeNumberProcessors - 1,
672                        KeLoaderBlock);
673 
674     /* Set the priority of this thread to 0 */
675     Thread = KeGetCurrentThread();
676     Thread->Priority = 0;
677 
678     /* Force interrupts enabled and lower IRQL back to DISPATCH_LEVEL */
679     _enable();
680     KeLowerIrql(DISPATCH_LEVEL);
681 
682     /* Set the right wait IRQL */
683     Thread->WaitIrql = DISPATCH_LEVEL;
684 
685     /* Jump into the idle loop */
686     KiIdleLoop();
687 }
688 
689 static
690 VOID
691 KiMarkPageAsReadOnly(
692     PVOID Address)
693 {
694     PHARDWARE_PTE PointerPte;
695 
696     /* Make sure the address is page aligned */
697     ASSERT(ALIGN_DOWN_POINTER_BY(Address, PAGE_SIZE) == Address);
698 
699     /* Get the PTE address */
700     PointerPte = ((PHARDWARE_PTE)PTE_BASE) + ((ULONG_PTR)Address / PAGE_SIZE);
701     ASSERT(PointerPte->Valid);
702     ASSERT(PointerPte->Write);
703 
704     /* Set as read-only */
705     PointerPte->Write = 0;
706 
707     /* Flush the TLB entry */
708     __invlpg(Address);
709 }
710 
711 INIT_FUNCTION
712 VOID
713 NTAPI
714 KiSystemStartup(IN PLOADER_PARAMETER_BLOCK LoaderBlock)
715 {
716     ULONG Cpu;
717     PKTHREAD InitialThread;
718     ULONG InitialStack;
719     PKGDTENTRY Gdt;
720     PKIDTENTRY Idt;
721     KIDTENTRY NmiEntry, DoubleFaultEntry;
722     PKTSS Tss;
723     PKIPCR Pcr;
724     KIRQL DummyIrql;
725 
726     /* Boot cycles timestamp */
727     BootCycles = __rdtsc();
728 
729     /* Save the loader block and get the current CPU */
730     KeLoaderBlock = LoaderBlock;
731     Cpu = KeNumberProcessors;
732     if (!Cpu)
733     {
734         /* If this is the boot CPU, set FS and the CPU Number*/
735         Ke386SetFs(KGDT_R0_PCR);
736         __writefsdword(KPCR_PROCESSOR_NUMBER, Cpu);
737 
738         /* Set the initial stack and idle thread as well */
739         LoaderBlock->KernelStack = (ULONG_PTR)P0BootStack;
740         LoaderBlock->Thread = (ULONG_PTR)&KiInitialThread;
741     }
742 
743     /* Save the initial thread and stack */
744     InitialStack = LoaderBlock->KernelStack;
745     InitialThread = (PKTHREAD)LoaderBlock->Thread;
746 
747     /* Clean the APC List Head */
748     InitializeListHead(&InitialThread->ApcState.ApcListHead[KernelMode]);
749 
750     /* Initialize the machine type */
751     KiInitializeMachineType();
752 
753     /* Skip initial setup if this isn't the Boot CPU */
754     if (Cpu) goto AppCpuInit;
755 
756     /* Get GDT, IDT, PCR and TSS pointers */
757     KiGetMachineBootPointers(&Gdt, &Idt, &Pcr, &Tss);
758 
759     /* Setup the TSS descriptors and entries */
760     Ki386InitializeTss(Tss, Idt, Gdt);
761 
762     /* Initialize the PCR */
763     RtlZeroMemory(Pcr, PAGE_SIZE);
764     KiInitializePcr(Cpu,
765                     Pcr,
766                     Idt,
767                     Gdt,
768                     Tss,
769                     InitialThread,
770                     (PVOID)KiDoubleFaultStack);
771 
772     /* Set us as the current process */
773     InitialThread->ApcState.Process = &KiInitialProcess.Pcb;
774 
775     /* Clear DR6/7 to cleanup bootloader debugging */
776     __writefsdword(KPCR_TEB, 0);
777     __writefsdword(KPCR_DR6, 0);
778     __writefsdword(KPCR_DR7, 0);
779 
780     /* Setup the IDT */
781     KeInitExceptions();
782 
783     /* Load Ring 3 selectors for DS/ES */
784     Ke386SetDs(KGDT_R3_DATA | RPL_MASK);
785     Ke386SetEs(KGDT_R3_DATA | RPL_MASK);
786 
787     /* Save NMI and double fault traps */
788     RtlCopyMemory(&NmiEntry, &Idt[2], sizeof(KIDTENTRY));
789     RtlCopyMemory(&DoubleFaultEntry, &Idt[8], sizeof(KIDTENTRY));
790 
791     /* Copy kernel's trap handlers */
792     RtlCopyMemory(Idt,
793                   (PVOID)KiIdtDescriptor.Base,
794                   KiIdtDescriptor.Limit + 1);
795 
796     /* Restore NMI and double fault */
797     RtlCopyMemory(&Idt[2], &NmiEntry, sizeof(KIDTENTRY));
798     RtlCopyMemory(&Idt[8], &DoubleFaultEntry, sizeof(KIDTENTRY));
799 
800 AppCpuInit:
801     /* Loop until we can release the freeze lock */
802     do
803     {
804         /* Loop until execution can continue */
805         while (*(volatile PKSPIN_LOCK*)&KiFreezeExecutionLock == (PVOID)1);
806     } while(InterlockedBitTestAndSet((PLONG)&KiFreezeExecutionLock, 0));
807 
808     /* Setup CPU-related fields */
809     __writefsdword(KPCR_NUMBER, Cpu);
810     __writefsdword(KPCR_SET_MEMBER, 1 << Cpu);
811     __writefsdword(KPCR_SET_MEMBER_COPY, 1 << Cpu);
812     __writefsdword(KPCR_PRCB_SET_MEMBER, 1 << Cpu);
813 
814     /* Initialize the Processor with HAL */
815     HalInitializeProcessor(Cpu, KeLoaderBlock);
816 
817     /* Set active processors */
818     KeActiveProcessors |= __readfsdword(KPCR_SET_MEMBER);
819     KeNumberProcessors++;
820 
821     /* Check if this is the boot CPU */
822     if (!Cpu)
823     {
824         /* Initialize debugging system */
825         KdInitSystem(0, KeLoaderBlock);
826 
827         /* Check for break-in */
828         if (KdPollBreakIn()) DbgBreakPointWithStatus(DBG_STATUS_CONTROL_C);
829 
830         /* Make the lowest page of the boot and double fault stack read-only */
831         KiMarkPageAsReadOnly(P0BootStackData);
832         KiMarkPageAsReadOnly(KiDoubleFaultStackData);
833     }
834 
835     /* Raise to HIGH_LEVEL */
836     KeRaiseIrql(HIGH_LEVEL, &DummyIrql);
837 
838     /* Switch to new kernel stack and start kernel bootstrapping */
839     KiSwitchToBootStack(InitialStack & ~3);
840 }
841