// TITLE("System Initialization") //++ // // Module Name: // // start.s // // Abstract: // // This module implements the code necessary to initially startup the // NT system. // // Author: // // Bernard Lint 8-Dec-1995 // // Environment: // // Kernel mode only. // // Revision History: // // Based on MIPS version (from David N. Cutler (davec) 5-Apr-1991) // //-- #include "ksia64.h" PublicFunction(SwapFromIdle) PublicFunction(KeBugCheck) PublicFunction(KiInitializeKernel) PublicFunction(KeLowerIrql) PublicFunction(KiNormalSystemCall) PublicFunction(KiRetireDpcList) PublicFunction(KeAcquireQueuedSpinLockAtDpcLevel) PublicFunction(KeReleaseQueuedSpinLockFromDpcLevel) PublicFunction(KeTryToAcquireQueuedSpinLockRaiseToSynch) .global __imp_HalProcessorIdle .global KiIvtBase .global KiIA64PtaContents #if !defined(NT_UP) .global HalAllProcessorsStarted .global KeNumberProcessors .global KiBarrierWait .global KiKernelPcrPage #endif // !defined(NT_UP) #if DBG PublicFunction(KdPollBreakIn) PublicFunction(DbgBreakPointWithStatus) .global KdDebuggerEnabled #endif // DBG SBTTL("System Initialization") //++ // Routine: // // VOID // KiSystemBegin ( // PLOADER_PARAMETER_BLOCK) // // Routine Description: // // This routine is called when the NT system begins execution. // Its function is to initialize system hardware state, call the // kernel initialization routine, and then fall into code that // represents the idle thread for all processors. // // Arguments: // // a0 - Supplies a pointer to the loader parameter block. // // Return Value: // // None. // // Note: // // On entry the global pointer (gp) is initialized for this module (the // NTOS kernel) by the loader. // //-- NESTED_ENTRY(KiSystemBegin) ALTERNATE_ENTRY(_start) NESTED_SETUP(1,2,6,0) // Also see "alloc" below // // Register aliases // rpT1 = t0 rpT2 = t1 rpT3 = t2 rT1 = t3 rT2 = t4 rT3 = t5 rT4 = t6 rpLpb = t7 rThread = t8 rPcrPfn = t9 rPrcb = t10 rPcr2Pfn = t11 rProcNum = t12 rPKR = t13 rPkrNum = t14 rRR = t15 rKstack = t16 rVa = t17 rPcrTr = t18 rpPcr = t19 FAST_DISABLE_INTERRUPTS // disable interrupts // // invalidate ITR used by SAL. // mov rT2 = 0x14 << 2 movl rT3 = 0x03f00000 ;; ptr.i rT3, rT2 ALTERNATE_ENTRY(KiInitializeSystem) mov ar.rsc = r0 // put RSE in lazy mode movl rT2 = KiIvtBase ;; rsm 1 << PSR_IC // PSR.ic = 0 mov cr.iva = rT2 #if !defined(NT_UP) add rpT1 = @gprel(KiKernelPcrPage), gp ;; ld8 rPcrPfn = [rpT1] #else mov rPcrPfn = 0 #endif ;; srlz.d add rpT2 = LpbPcrPage, a0 // -> PCR page number cmp.eq pt0, pt1 = 0, rPcrPfn ;; // // Initialize fixed TLB entries that map the PCR into system and user space. // N.B. These pages are per *processor* so we need a fixed mapping. // (pt0) ld8 rPcrPfn = [rpT2] // set PCR page number movl rVa = KiPcr // set virtual address of PCR ;; mov cr.ifa = rVa // setup IFA for insert mov rT1 = PAGE_SHIFT << IDTR_PS shl rPcrPfn = rPcrPfn, PAGE_SHIFT // shift to PPN field ;; mov cr.itir = rT1 // setup IDTR movl rPcrTr = KIPCR_TR_INITIAL // PCR translation except for PPN mov rT2 = DTR_KIPCR_INDEX ;; or rPcrTr = rPcrPfn, rPcrTr // form full TR ;; itr.d dtr[rT2] = rPcrTr // insert PCR TR to DTR ssm 1 << PSR_IC // PSR.ic = 1 ;; srlz.i // I serialize add rpT1 = LpbKernelStack, a0 // -> idle thread stack mov rpLpb = a0 // save a0 ;; LDPTR (rKstack, rpT1) // rKstack = idle thread stack // N.B. This is also the base // of backing store ;; mov ar.bspstore = rKstack // setup BSP .fframe STACK_SCRATCH_AREA add sp = -STACK_SCRATCH_AREA, rKstack // set sp ;; loadrs // invalidate RSE invala ;; mov ar.rsc = RSC_KERNEL // put RSE in eager mode ;; alloc rT4 = ar.pfs,1,2,6,0 // keep in sync with entry point alloc mov savedbrp = zero // setup bogus brp and pfs to mov savedpfs = zero // stop the debugger PROLOGUE_END // // Get page frame numbers for the PCR and PDR pages that were allocated by // the OS loader. Page directory is 4 physically contiguous pages. // add rpT1 = LpbPrcb, rpLpb // -> PRCB dep.z rRR = UREGION_INDEX, RR_INDEX, RR_INDEX_LEN ;; LDPTR (rPrcb, rpT1) // get processor block address movl rT2 = (START_PROCESS_RID << RR_RID)| RR_PS_VE ;; // // set RR[0], Region ID (RID) = 1, Page Size (PS) = 8K, VHPT enabled (VE) = 1 // mov rr[rRR] = rT2 // initialize rr[0] movl rT1 = (START_SESSION_RID << RR_RID) | RR_PS_VE ;; // // set RR[1] // movl rRR = SADDRESS_BASE // initialize ;; mov rr[rRR] = rT1 // hydra region rr[1] ;; // // set RR[4], Region ID (RID) = 0, Page Size (PS) = 64K, VHPT enabled (VE) = 0 // // // set RR[2] to RR[7], RID = KSEG3_RID, Page Size = 8K, VHPT disabled // movl rRR = 2 << RR_INDEX movl rT2 = (KSEG3_RID << RR_RID) | (PAGE_SHIFT << RR_PS) ;; mov rr[rRR] = rT2 // initialize rr[2] movl rRR = 3 << RR_INDEX ;; mov rr[rRR] = rT2 // initialize rr[3] movl rRR = 4 << RR_INDEX ;; mov rr[rRR] = rT2 // initialize rr[4] movl rRR = 5 << RR_INDEX ;; mov rr[rRR] = rT2 // initialize rr[5] movl rRR = 6 << RR_INDEX ;; mov rr[rRR] = rT2 // initialize rr[6] // // Protection Key Registers // mov rPKR = zero // pkr index = 0 mov rT1 = PKR_VALID // rr[0].v=1, pkr[0].key=0 mov rT2 = START_GLOBAL_RID ;; mov pkr[rPKR] = rT1 add rPKR = 1, rPKR // increment PKR number shl rT2 = rT2, RR_RID ;; or rT2 = rT1, rT2 ;; mov pkr[rPKR] = rT2 // pkr[1].v=1, pkr[1].key=START_GLOBAL_RID add rPKR = 1, rPKR // increment PKR number movl rT2 = START_PROCESS_RID ;; shl rT2 = rT2, RR_RID ;; or rT2 = rT1, rT2 ;; mov pkr[rPKR] = rT2 // pkr[1].v=1, pkr[1].key=START_GLOBAL_RID add rPKR = 1, rPKR // increment PKR number mov rT2 = zero ;; Ksb_PKRLoop: mov pkr[rPKR] = rT2 // set PKR invalid add rPKR = 1, rPKR // increment PKR number ;; cmp.gtu pt0 = PKRNUM, rPKR // at end? (pt0) br.cond.sptk.few.clr Ksb_PKRLoop ;; // // Initialize debug registers // mov rT1 = 0 ;; Ksb_DbrLoop: mov ibr[rT1] = r0 mov dbr[rT1] = r0 ;; #ifndef NO_12241 srlz.d #endif cmp.ne pt0 = 7, rT1 add rT1 = 1, rT1 (pt0) br.cond.sptk.few Ksb_DbrLoop ;; // // Initialize control registers: // DCR // PSR pk, it, dt enabled // ssm (1 << PSR_DI) | (1 << PSR_PP) | (1 << PSR_IC) | (1 << PSR_DFH) | (1 << PSR_AC) ;; rsm (1 << PSR_PK) | (1 << PSR_MFH) // must clear the mfh bit ;; srlz.i movl rT1 = DCR_INITIAL ;; mov cr.dcr = rT1 // // Clear TC // // Set up ITR entry 2 with EPC page for system call // movl rT4 = KiNormalSystemCall ptc.e zero add rpT1 = LpbKernelVirtualBase, rpLpb add rpT2 = LpbKernelPhysicalBase, rpLpb ;; LDPTR (rT2, rpT1) // virtual load point LDPTR (rT3, rpT2) // physical load point shr rT4 = rT4, PAGE_SHIFT // page number for syscall page ;; shr rT2 = rT2, PAGE_SHIFT // page number shr rT3 = rT3, PAGE_SHIFT // page number ;; sub rT2 = rT4, rT2 // page offset movl rVa = MM_EPC_VA ;; add rT3 = rT3, rT2 // compute pfn of syscall page movl rT2 = TR_VALUE(1,0,7,0,1,1,0,1) ;; shl rT3 = rT3, PAGE_SHIFT // set page number in TR ;; or rT2 = rT2, rT3 mov rT3 = ITR_EPC_INDEX ;; // // Clear PSR.IC bit // add rpT1 = LpbPcrPage2, a0 ;; ld8 rPcr2Pfn = [rpT1] // set second PCR page mov rT1 = PAGE_SHIFT << IDTR_PS rsm 1 << PSR_IC // PSR.ic = 0 ;; srlz.d mov cr.ifa = rVa // virtual address of epc page mov cr.itir = rT1 ;; itr.i itr[rT3] = rT2 movl rVa = KiPcr2 // set virtual address of PCR ;; mov cr.ifa = rVa // setup IFA for insert movl rPcrTr = KIPCR_TR_INITIAL // PCR translation except for PPN mov cr.itir = rT1 // setup IDTR mov rT2 = DTR_KIPCR2_INDEX shl rPcr2Pfn = rPcr2Pfn, PAGE_SHIFT // shift to PPN field ;; or rPcrTr = rPcr2Pfn, rPcrTr // form full TR ;; itr.d dtr[rT2] = rPcrTr // insert PCR TR to DTR ssm 1 << PSR_IC // PSR.ic = 1 ;; srlz.i // I serialize // // Set the cache policy for cached memory. // **** TBD **** // // Set the first level data and instruction cache fill size and size. // // **** TBD // // Set the second level data and instruction cache fill size and size. // // ***** TBD // // Set the data cache fill size and alignment values. // // **** TBD // // Set the instruction cache fill size and alignment values. // // **** TBD // // Sweep the data and instruction caches. // // **** TBD // // Initialize the fixed entries that map the PDR pages. // Setup page directory, pte's for page dir // **** TBD **** // // // Initialize the Processor Control Registers (PCR). // // // Initialize the minor and major version numbers. // mov rT1 = PCR_MINOR_VERSION // set minor version number movl rpPcr = KiPcr // get PCR address ;; add rpT1 = PcMinorVersion, rpPcr add rpT2 = PcMajorVersion, rpPcr mov rT2 = PCR_MAJOR_VERSION // set major version number ;; st2 [rpT1] = rT1 // store minor st2 [rpT2] = rT2 // store major add rpT3 = PcPrcb, rpPcr // -> PCR.Prcb ;; // // Set address of processor block. // st8 [rpT3] = rPrcb // store Prcb address // // Initialize the addresses of various data structures that are referenced // from the exception and interrupt handling code. // // N.B. The panic stack is a separate stack that is used when the current // kernel stack overlfows. // add rpT1 = PcInitialStack,rpPcr // -> initial kernel stack address in PCR add rpT2 = LpbPanicStack, rpLpb // -> lpb panic stack address add rpT3 = PcPanicStack, rpPcr // -> panic stack address in PCR ;; LDPTRINC (rT2, rpT2, LpbThread-LpbPanicStack) // panic stack address st8 [rpT1] = rKstack, PcKernelGP-PcInitialStack ;; LDPTR (rThread, rpT2) // -> current (idle) thread st8 [rpT3] = rT2, PcCurrentThread-PcPanicStack // set PCR panic stack address ;; st8 [rpT3] = rThread // set PCR current thread st8 [rpT1] = gp // save GP mov rT1 = HIGH_LEVEL ;; SET_IRQL(rT1) // Set to highest IRQL // // Clear floating status and zero the count and compare registers. // mov ar.ccv = zero movl rT1 = FPSR_FOR_KERNEL ;; mov ar.fpsr = rT1 mov ar.ec = zero mov ar.lc = zero // // Set system dispatch address limits used by get and set context. // ***** TBD ****** // // Set the default cache error routine address. // ****** TBD ******* // // Sweep the data and instruction caches. // **** TBD ******* // // Setup arguments and call kernel initialization routine. // add rpT1 = LpbProcess, rpLpb // -> idle process address add rpT2 = PbNumber, rPrcb mov out3 = rPrcb // arg 4 is current PRCB ;; LDPTR (out0, rpT1) // arg 1 is process mov out1 = rThread // arg 2 is thread mov out2 = rKstack // arg 3 is kernel stack ld1 out4 = [rpT2] // get processor number mov out5 = rpLpb // arg 6 is pointer to LPB br.call.sptk.many.clr brp = KiInitializeKernel ;; // (C code) alloc t0 = ar.pfs,0,0,0,0 mov brp = zero // setup a bogus brp to stop debugger br KiIdleLoop // branch to KIIdleLoop() ;; // // Never get to this point! // NESTED_EXIT(KiSystemBegin) // //++ // // VOID // KiIdleLoop ( // VOID // ) // // Routine Description: // // This is the idle loop for NT. This code runs in a thread for // each processor in the system. The idle thread runs at IRQL // DISPATCH_LEVEL and polls for work. // // Arguments: // // None. // // Return Value: // // None. (This routine never returns). // // When another thread is selected to run, SwapContext is called. // Normally, SwapContext saves and restores the non-volatile context. // The idle loop never returns so the preserved registers of the caller // do not need to be saved. // In other architectures, the idle loop pre-initializes the storage area // (switch frame) where SwapContext would normally save the preserved // registers with values that the idle loop needs // in those registers upon return from SwapContext and skips over the // register save on the way into SwapContext (alternate entry point // SwapFromIdle). // In this design the idle loop registers are preserved in // the register stack which is saved in the kernel backing store for the // idle thread. This allows us to skip the restore in SwapContext (not yet // implemented). // // All callers to SwapContext pass the following arguments: // // -- s0 = Prcb // -- s1 = current (previous) thread // -- s2 = new (next) thread // // Idle also enters SwapContext at SwapFromIdle with sp pointing to the switch // frame for preserved state. // // Since all registers used by the idle are saved in the register stack, // no registers need be recomputed on return from SwapContext. // //-- NESTED_ENTRY(KiIdleLoop) NESTED_SETUP(0,6,2,0) // // allocate and build switch frame // .fframe SwitchFrameLength add sp = -SwitchFrameLength, sp ;; add t0 = ExFltS3+SwExFrame+STACK_SCRATCH_AREA, sp add t1 = ExFltS2+SwExFrame+STACK_SCRATCH_AREA, sp ;; .save.f 0xC stf.spill [t0] = fs3, ExFltS1-ExFltS3 // save fs3 stf.spill [t1] = fs2, ExFltS0-ExFltS2 // save fs2 mov t10 = bs4 ;; .save.f 0x3 stf.spill [t0] = fs1, ExIntS3-ExFltS1 // save fs1 stf.spill [t1] = fs0, ExIntS2-ExFltS0 // save fs0 mov t11 = bs3 ;; .save.g 0xC .mem.offset 0,0 st8.spill [t0] = s3, ExIntS1-ExIntS3 // save s3 .mem.offset 8,0 st8.spill [t1] = s2, ExIntS0-ExIntS2 // save s2 mov t12 = bs2 ;; .save.g 0x3 .mem.offset 0,0 st8.spill [t0] = s1, ExBrS4-ExIntS1 // save s1 .mem.offset 8,0 st8.spill [t1] = s0, ExBrS3-ExIntS0 // save s0 mov t13 = bs1 ;; .save.b 0x18 st8 [t0] = t10, ExBrS2-ExBrS4 // save bs4 st8 [t1] = t11, ExBrS1-ExBrS3 // save bs3 mov t4 = ar.unat // captured Nats of s0-s3 ;; .save.b 0x6 st8 [t0] = t12, ExBrS0-ExBrS2 // save bs2 st8 [t1] = t13, ExApEC-ExBrS1 // save bs1 mov t14 = bs0 ;; .save.b 0x1 st8 [t0] = t14, ExApLC-ExBrS0 // save bs0 .savepsp ar.pfs, ExceptionFrameLength-ExApEC-STACK_SCRATCH_AREA st8 [t1] = t16, ExIntNats-ExApEC mov t15 = ar.lc ;; .savepsp ar.lc, ExceptionFrameLength-ExApLC-STACK_SCRATCH_AREA st8 [t0] = t15 .savepsp @priunat, ExceptionFrameLength-ExIntNats-STACK_SCRATCH_AREA st8 [t1] = t4 // save Nats of s0-s3 nop.i 0 ;; PROLOGUE_END // // Register aliases // rpT1 = t0 rpT2 = t1 rpT3 = t2 rT1 = t3 rT2 = t4 rT3 = t5 #if !defined(NT_UP) rpNumProc = t7 rpBWait = t8 rpDispLock = t9 #endif // !defined(NT_UP) rpNextTh = t10 #if DBG rDbgCount = t11 rKdEnable = t12 #endif //DBG pEmty = pt1 pIdle = pt2 #if !defined(NT_UP) pLoop = pt6 #endif // !defined(NT_UP) #if DBG pBrk = ps2 pNotZero = ps3 #endif // DBG rpHPI = loc2 rHalGP = loc3 rKerGP = loc4 #if !defined(NT_UP) rProcNum = loc5 #endif // !defined(NT_UP) // // Initialize SwitchFPSR, SwitchPFS, SwitchRp in the switch frame // mov rT3 = ar.bsp movl rT2 = KiIdleReturn add rpT1 = SwPFS+STACK_SCRATCH_AREA, sp mov rKerGP = gp // save the kernel's gp mov rT1 = 0x308 // must match the values specified // by the alloc instruction at // the entry of the KiIdleLoop ;; st8.nta [rpT1] = rT1, SwRp-SwPFS // set pfs in the switch frame add rT3 = 0x30, rT3 // 6 local registers ;; st8.nta [rpT1] = rT2, SwFPSR-SwRp // set brp in the switch frame movl rT1 = FPSR_FOR_KERNEL ;; extr.u rpT3 = rT3, 0, 9 st8.nta [rpT1] = rT1, SwRnat-SwFPSR ;; cmp.gtu pt1 = 0x30, rpT3 // Is there a slot for NAT bits? st8.nta [rpT1] = zero, SwBsp-SwRnat ;; (pt1) add rT3 = 8, rT3 // Adjust for NAT bits. ;; st8.nta [rpT1] = rT3 movl rpT1 = KiPcr + PcPrcb ;; // // In a multiprocessor system the boot processor proceeds directly into // the idle loop. As other processors start executing, however, they do // not directly enter the idle loop and spin until all processors have // been started and the boot master allows them to proceed. // // // Setup initial idle loop register values // LDPTRINC (s0, rpT1, PcCurrentThread-PcPrcb) // address of PRCB add rpT2 = @gprel(__imp_HalProcessorIdle), gp ;; LDPTR (s2, rpT1) // idle thread LDPTR (rpT2, rpT2) // -> function pointer add rpT3 = PbNumber, s0 ;; ld1 rProcNum = [rpT3] ld8 rpHPI = [rpT2], PlGlobalPointer-PlEntryPoint // entry point ;; // // Control reaches here with IRQL at HIGH_LEVEL. Lower IRQL to // DISPATCH_LEVEL and set wait IRQL of idle thread. // ld8 rHalGP = [rpT2] // Hal GP add rpT1 = ThWaitIrql, s2 // -> thread WaitIrql mov out0 = DISPATCH_LEVEL // get dispatch level IRQL ;; st1 [rpT1] = out0 // set wait IRQL of idle thread br.call.sptk.few.clr brp = KeLowerIrql // call KeLowerIrql(IRQL) ;; FAST_ENABLE_INTERRUPTS mov gp = rKerGP ;; // // In a multiprocessor system the boot processor proceeds directly into // the idle loop. As other processors start executing, however, they do // not directly enter the idle loop and spin until all processors have // been started and the boot master allows them to proceed. // #if !defined(NT_UP) add rpBWait = @gprel(KiBarrierWait), gp ;; Kil_WaitLoop: ld4 rT1 = [rpBWait] // get barrier wait value ;; cmp.ne pLoop = zero, rT1 // loop if not zero (pLoop) br.dpnt.few.clr Kil_WaitLoop // spin until allowed to proceed #endif // !defined(NT_UP) KiIdleReturn: mov s1 = s2 // s1 <- IdleThread #if DBG mov rDbgCount = 20 * 1000 // set breakin loop counter #endif // DBG ;; KiIdleSwitchBlocked: mov rT1 = DISPATCH_LEVEL ;; SET_IRQL(rT1) // // The following loop is executed for the life of the system. // Kil_TopOfIdleLoop:: mov gp = rKerGP // restore gp // // If processor 0, check for debugger breakin, otherwise just check for // DPCs again. // #if DBG #if !defined(NT_UP) cmp4.ne pNotZero = zero, rProcNum // pNotZero = not processor zero (pNotZero) br.cond.dptk.few.clr Kil_CheckDpcList // br if not processor zero #endif // !defined(NT_UP) // // Check if the debugger is enabled, and whether it is time to poll // for a debugger breakin. (This check is only performed on cpu 0). // sub rDbgCount = rDbgCount,zero,1 // decrement poll counter ;; add rKdEnable = @gprel(KdDebuggerEnabled), gp cmp.eq pBrk = rDbgCount, zero // zero yet? ;; (pBrk) ld1 rKdEnable = [rKdEnable] // check if debugger enabled (pBrk) mov rDbgCount = 20 * 1000 // set breakin loop counter ;; (pBrk) cmp.ne pBrk = rKdEnable, zero // pBrk = 1 if Kd enabled (pBrk) br.call.dpnt.few.clr brp=KdPollBreakIn // check if breakin requested ;; mov gp = rKerGP // restore gp (pBrk) cmp.ne pBrk = v0, zero // ne => break in requested mov out0 = DBG_STATUS_CONTROL_C (pBrk) br.call.sptk brp = DbgBreakPointWithStatus ;; mov gp = rKerGP // restore gp #endif // DBG // // Disable interrupts and check if there is any work in the DPC list. // Kil_CheckDpcList: // // Process the deferred procedure call list for the current processor. // FAST_ENABLE_INTERRUPTS // give interrupts a chance ;; srlz.d add rpT1 = PbDpcQueueDepth, s0 add rpNextTh = PbNextThread, s0 // -> next thread ;; FAST_DISABLE_INTERRUPTS // disable interrupts ;; ld4.nta rT1 = [rpT1] mov out0 = s0 // PRCB ;; cmp4.eq pt0, pt1 = rT1, zero // if eq, queue empty movl rpT1 = KiPcr+PcDispatchInterrupt ;; (pt1) st1 [rpT1] = zero // clear dispatch interrupt req (pt0) br.cond.dpnt Kil_CheckNextThread (pt1) br.call.sptk.few.clr brp = KiRetireDpcList ;; add rpNextTh = PbNextThread, s0 // -> next thread mov gp = rKerGP // restore gp #if DBG mov rDbgCount = 20 * 1000 // set breakin loop counter #endif // DBG ;; // // Check if a thread has been selected to run on this processor // Kil_CheckNextThread: ld8 s2 = [rpNextTh] // next thread mov rT1 = SYNCH_LEVEL ;; cmp.eq pIdle = s2, zero // if no thread to run (pIdle) br.dpnt.few.clr Kil_Idle // br to Idle // // A thread has been selected for execution on this processor. Acquire // the context swap lock, get the thread address again (it may have // changed), clear the address of the next thread in the processor block, // and call swap context to start execution of the selected thread. // SET_IRQL(rT1) FAST_ENABLE_INTERRUPTS #if !defined(NT_UP) add out0 = PbLockQueue + (LockQueueContextSwapLock * 2 * 8), s0 add s2 = PbNextThread, s0 // -> next thread br.call.sptk brp = KeAcquireQueuedSpinLockAtDpcLevel ;; // // Reread the next thread because it may be changed in a MP system. // // The selected thread may be blocked from switching at this time // if it is being scheduled on this processor because it is being // removed from another processor. The switch is blocked until // the thread is completely removed from the other processor. In // this case, drop the context swap lock and continue execution as // if resuming from a context switch. (The release below returns // to KiIdleSwitchBlocked above). // ld8 s2 = [s2] // reread next thread movl rpT2 = KiIdleSwitchBlocked ;; add rpT1 = ThIdleSwapBlock, s2 // &NewThread->IdleSwapBlock mov brp = rpT2 cmp.eq pt0 = s2, s1 // check for swap idle to idle ;; ld1 rT1 = [rpT1], ThState-ThIdleSwapBlock add out0 = PbLockQueue + (LockQueueContextSwapLock * 2 * 8), s0 (pt0) br.dpnt.few.clr Kil_Idle2Idle // rare case, idle to idle ;; cmp.ne pIdle = rT1, zero add rpT2 = PbCurrentThread, s0 // -> address of current thread (pIdle) br.call.spnt bt0 = KeReleaseQueuedSpinLockFromDpcLevel ;; #else add rpT2 = PbCurrentThread, s0 // -> address of current thread add rpT1 = ThState, s2 ;; #endif // !defined(NT_UP) // set new thread as current st8 [rpT2] = s2, PbNextThread-PbCurrentThread mov rT1 = Running ;; st1 [rpT1] = rT1 // set new thread state to running st8.rel [rpT2] = zero // clear address of next thread // // Swap context to new thread // (returns to KiIdleReturn above). // br.call.sptk.few.clr brp = SwapFromIdle ;; // // There are no entries in the DPC list and a thread has not been selected // for execution on this processor. Call the HAL so power managment can be // performed. // // N.B. The HAL is called with interrupts disabled. The HAL will return // with interrupts enabled. // Kil_Idle: mov bt0 = rpHPI movl rT1 = Kil_TopOfIdleLoop ;; mov gp = rHalGP // set Hal GP mov brp = rT1 br.call.dpnt.few.clr bt1 = bt0 // call HalProcessorIdle ;; // does not return here. // // In the event that a thread was scheduled to run on this processor // but before the idle loop picked it up, it was made inelligible for // this processor and there is no other thread to run, the idle thread // will have been selected as the NextThread for this processor and // this processor will have been marked idle in KiIdleSummary. // // It is then possible for another thread to be selected for this processor // between the time the idle loop picks up the NextThread field and clears // it. // // To avoid this rare case, if the switch is from the idle thread to the // idle thread, we need to drop the context swap lock, acquire the // dispatcher lock and if the next thread field is still the idle thread, // clear it and continue to idle. If it is no longer the idle thread, // switch to that thread. // Kil_Idle2Idle: add s2 = PbNextThread, s0 // get &Prcb->NextThread br.call.sptk brp = KeReleaseQueuedSpinLockFromDpcLevel ;; add out0 = PbLockQueue + (LockQueueDispatcherLock * 2 * 8), s0 br.call.sptk brp = KeAcquireQueuedSpinLockAtDpcLevel ;; add out0 = PbLockQueue + (LockQueueDispatcherLock * 2 * 8), s0 ld8 rT1 = [s2] // get Prcb->NextThread ;; cmp.eq pt0 = rT1, s2 // check if still Idle Thread ;; (pt0) st8 [s2] = zero // clear Prcb->NextThread br.call.sptk brp = KeReleaseQueuedSpinLockFromDpcLevel ;; br KiIdleSwitchBlocked // loop. NESTED_EXIT(KiIdleLoop) #if !defined(NT_UP) //++ // Routine: // // VOID // KiOSRendezvous ( // ) // // Routine Description: // // OS rendezvous entry point called from SAL for MP boot. // Establish kernel mapping and rfi to KiInitializeSystem with // translation turned on. // // Arguments: // // Return Value: // // None. // //-- .global MmSystemParentTablePage .global MiNtoskrnlPhysicalBase .global MiNtoskrnlVirtualBase .global MiNtoskrnlPageShift LEAF_ENTRY(KiOSRendezvous) mov t5 = ip // get the physical addr for KiOSRendezvous mov psr.l = zero // initialize psr.l movl t0 = KSEG0_BASE ;; mov ar.rsc = zero // invalidate register stack mov t1 = (START_GLOBAL_RID << RR_RID) | (PAGE_SHIFT << RR_PS) | (1 << RR_VE) ;; // // Initialize Region Register for kernel // loadrs mov rr[t0] = t1 // // Setup translation for kernel/hal binary. // movl t0 = KSEG0_BASE; ;; movl t2 = MiNtoskrnlPhysicalBase movl t4 = MiNtoskrnlPageShift movl t0 = MiNtoskrnlVirtualBase movl t3 = KiOSRendezvous ;; sub t6 = t2, t3 sub t7 = t4, t3 sub t0 = t0, t3 ;; add t6 = t5, t6 // get a physical addr for MiNtoskrnlPhysicalBase add t7 = t5, t7 // get a physical addr for MiNtoskrnlPageShift add t0 = t5, t0 // get a physical addr for MiNtoskrnlVirtualBase ;; ld8 t6 = [t6] ld4 t7 = [t7] ld8 t0 = [t0] movl t8 = VALID_KERNEL_EXECUTE_PTE ;; mov cr.ifa = t0 or t2 = t6, t8 shl t1 = t7, PS_SHIFT ;; mov cr.itir = t1 mov t3 = DTR_KERNEL_INDEX ;; itr.d dtr[t3] = t2 ;; itr.i itr[t3] = t2 // // Setup VHPT // movl t0 = KiIA64PtaContents movl t3 = KiOSRendezvous ;; sub t6 = t0, t3 ;; add t6 = t5, t6 ;; ld8 t6 = [t6] ;; mov cr.pta = t6 // // Turn on address translation // movl t1 = (1 << PSR_BN) | (1 << PSR_IT) | (1 << PSR_DA) | (1 << PSR_RT) | (1 << PSR_DT) | (1 << PSR_IC) ;; mov cr.ipsr = t1 // // Branch to KiInitializeSystem // // Need to do a "rfi" in order set "it" bits in the PSR. // This is the only way to set them. // movl t0 = KiOSRendezvousStub ;; mov cr.iip = t0 ;; rfi ;; .global KeLoaderBlock KiOSRendezvousStub: alloc t0 = 0,0,1,0 movl gp = _gp mov t9 = PAGE_SHIFT << PS_SHIFT movl t8 = KADDRESS_BASE ;; // // Set up the VHPT table // thash t8 = t8 add t7 = @gprel(MmSystemParentTablePage), gp ;; ld8 t7 = [t7] rsm 1 << PSR_IC // PSR.ic = 0 ;; srlz.d thash t8 = t8 movl t6 = PDR_TR_INITIAL ;; // // Install DTR for the kernel parent page table // thash t8 = t8 mov t10 = DTR_KTBASE_INDEX shl t7 = t7, PAGE_SHIFT ;; mov cr.ifa = t8 or t7 = t7, t6 mov cr.itir = t9 ;; itr.d dtr[t10] = t7 ssm 1 << PSR_IC // PSR.ic = 1 ;; srlz.i // I serialize add out0 = @gprel(KeLoaderBlock), gp ;; ld8 out0 = [out0] // dereference pointer movl t0 = KiInitializeSystem ;; mov bt0 = t0 br.call.sptk brp = bt0 // branch to entry point LEAF_EXIT(KiOSRendezvous) #endif // !defined(NT_UP)