Windows2000/private/ntos/ke/axp64/start.s
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// TITLE( "Start System" )
// Copyright (c) 1992 Digital Equipment Corporation
// Module:
// start.s
// Abstract:
// This module implements the code necessary to iniitially start NT
// on an alpha - it includes the routine that first receives control
// when the loader executes the kernel.
// Author:
// Joe Notarangelo 02-Apr-1992
// Environment:
// Kernel Mode only.
// Revision History:
#include "ksalpha.h"
#define TotalFrameLength (KERNEL_STACK_SIZE - (TrapFrameLength + \
ExceptionFrameLength) )
// Global Variables
.data
#ifdef NT_UP
// These global variables are useful only for uni-processor systems
// as they are per-processor values on MP systems.
.globl KiPcrBaseAddress
KiPcrBaseAddress:
.long 0 : 1
.globl KiCurrentThread
KiCurrentThread:
.long 0 : 1
#endif //NT_UP
SBTTL( "System Startup" )
// Routine Description:
// This routine represents the final stage of the loader. It is
// responsible for installing the loaded PALcode image and transfering
// control to the startup code in the kernel.
// KiSystemStartupContinue is the routine called when NT begins execution.
// The first code that must be executed is the PALcode, it must be entered
// in PAL mode. The PALcode will return to the address in the return
// address register (ra). This function sets ra to the beginning of the
// native system code that normally executes to setup the NT operating
// environment - so that the PAL "returns" to the normal system start code.
// N.B. This code assumes that the I-cache is coherent.
// N.B. This routine does not execute in the context of the operating
// system but instead executes in the context of the firmware
// PAL environment. This routine can only use those services
// guaranteed to exist in the firmware. The only PAL services
// that can be counted on are: swppal, imb, and halt.
// Arguments:
// LoaderBlock (a0) - Supplies pointer to Loader Parameter Block.
// Return Value:
// None.
.struct 0
SsRa: .space 8 // Save ra
.space 8 // for stack alignment
SsFrameLength:
NESTED_ENTRY(KiSystemStartup, SsFrameLength, ra)
ALTERNATE_ENTRY( KiStartProcessor )
lda sp, -SsFrameLength(sp) // allocate stack frame
stq ra, SsRa(sp) // save ra
PROLOGUE_END
//
// Prepare arguments for SWPPAL and Kernel. This assumes that
// the SWPPAL does not destroy any of the argument registers.
//
// a0 = Physical base address of PAL.
// a1 = PCR page frame number.
// a2 = Pointer to loader paramter block.
// ra = Address to return to from pal.
// Equals kernel start address.
//
bis a0, zero, a2 // copy Loader Block to a2
ldl a1, LpbPcrPage(a2) // get pcr page number
ldl a0, LpbPalBaseAddress(a2) // get PAL base address
sll a0, 32+3, a0 // strip off top bits
srl a0, 32+3, a0 // clear upper lw and kseg bits
lda ra, KiSystemStartupContinue // store OS start address in ra
//
// Jump to PAL via SWPPAL. Then return to continuation address in OS.
//
// a0 = new PAL base address
// ra = continuation address
SWPPAL // swap PAL images
//
// We should never get here!
//
ldq ra, SsRa(sp) // Restore ra
lda sp, SsFrameLength(sp) // Restore stack pointer
ret zero, (ra) // shouldn't get here
.end KiSystemStartup
SBTTL( "System Startup Continue" )
// Routine Description:
// KiSystemStartupContinue is the routine called when NT begins execution
// after loading the Kernel environment from the PAL.
// It's function is to register exception routines and system values
// with the pal code, call kernel initialization and fall into the idle
// thread code
// Arguments:
// PalBaseAddress(a0) - Supplies base address of the operating system
// PALcode.
// PcrPage(a1) - Supplies the PFN of the PCR page.
// LoaderBlock(a2) - Supplies a pointer to the loader parameter block.
// Return Value:
// None.
.struct 0
SscRa: .space 8 // return address
Fill: .space 8 // filler for alignment
SscFrameLength: // size of stack frame
NESTED_ENTRY( KiSystemStartupContinue, SscFrameLength, ra )
lda sp, -SscFrameLength(sp) // allocate stack frame
stq ra, SscRa(sp) // save ra
PROLOGUE_END
// Establish kernel stack pointer and kernel global pointer from
// parameter block.
ldl sp, LpbKernelStack(a2) // establish kernel sp
ldl gp, LpbGpBase(a2) // establish kernel gp
// Initialize PAL values, sp, gp, pcr, pdr, initial thread
bis a2, zero, s2 // save pointer to loader block
ldl s0, LpbPcrPage(s2) // get pcr page number
ldl a0, LpbPdrPage(s2) // get pdr page number
ldl a1, LpbThread(s2) // get idle thread address
ldil t0, KSEG0_BASE // kseg0 base address
bis a0, zero, s3 // save copy of pdr page number
sll a0, PAGE_SHIFT, a0 // physical address of pdr
sll s0, PAGE_SHIFT, s0 // physical address of pcr
bis a0, t0, a0 // kseg0 address of pdr
bis s0, t0, s0 // kseg0 address of pcr
bis a0, zero, s1 // save copy of pdr address
bis zero, zero, a2 // zero Teb for initial thread
ldl a3, LpbPanicStack(s2) // get Interrupt stack base
ldil a4, TotalFrameLength // set maximum kernel stack size
// sp - initial kernel sp
// gp - system gp
// a0 - pdr kseg0 address
// a1 - thread kseg0 address
// a2 - Teb address for initial thread
// a3 - Interrupt stack base
// a4 - Maximum kernel stack size
INITIALIZE_PAL
#ifdef NT_UP
// Save copies of the per-processor values in global variables for
// uni-processor systems.
lda t0, KiPcrBaseAddress // get address of PCR address
stl s0, 0(t0) // save PCR address
ldl t1, LpbThread(s2) // get address of idle thread
lda t0, KiCurrentThread // get address of thread address
stl t1, 0(t0) // save idle address as thread
#endif //NT_UP
// Establish recursive mapping of pde for ptes and hyperspace
// N.B. - page table page for hyperspace is page after pdr page
ldil t0, PTE_BASE // get pte base
sll t0, 32, t0 // clean upper bits
srl t0, 32+PDI_SHIFT-2, t0 // get offset of pde
bic t0, 3, t0 // longword aligned, clear low bits
addq t0, s1, t0 // kseg0 addr of pde
sll s3, PTE_PFN, t1 // shift pfn into place
bis t1, PTE_VALID_MASK, t1 // set valid bit
// bis t1, PTE_DIRTY_MASK, t1 // set dirty bit
stl t1, 0(t0) // store pde for pdr
ldil t2, (1 << PTE_PFN) // increment pfn by 1
addq t1, t2, t1 //
stl t1, 4(t0) // store hyperspace pde
// Establish mapping for special user data page.
// N.B. - page table page for this is page after hyperspace page table page
// actual data page is the next page.
ldil t0, SharedUserData // get shared data base
zap t0, 0xf0, t3 // clean upper bits
srl t3, PDI_SHIFT-2, t0 // get offset of pde
bic t0, 3, t0 // longword aligned, clear low bits
addq t0, s1, t0 // kseg0 addr of pde
addq t1, t2, t1 // increment pfn by 1
stl t1, 0(t0) // store user data page pde
zap t3, 0xf8, t3 // clean upper bits
srl t3, PTI_SHIFT-2, t3 // get offset of pte
bic t3, 3, t3 // longword aligned, clear low bits
addq t3, s1, t3
ldil t4, 2*PAGE_SIZE
addq t3, t4, t3 // kseg0 addr of pte
addq t1, t2, t1 // increment pfn by 1
stl t1, 0(t3)
// Register kernel exception entry points with the PALcode
lda a0, KiPanicException // bugcheck entry point
ldil a1, entryBugCheck //
WRITE_KERNEL_ENTRY_POINT //
lda a0, KiGeneralException // general exception entry point
ldil a1, entryGeneral //
WRITE_KERNEL_ENTRY_POINT //
lda a0, KiMemoryManagementException // memory mgmt exception entry
ldil a1, entryMM //
WRITE_KERNEL_ENTRY_POINT //
lda a0, KiInterruptException // interrupt exception entry point
ldil a1, entryInterrupt //
WRITE_KERNEL_ENTRY_POINT //
lda a0, KiSystemServiceException // syscall entry point
ldil a1, entrySyscall //
WRITE_KERNEL_ENTRY_POINT //
// Initialize fields in the pcr
ldil t1, PCR_MINOR_VERSION // get minor version
ldil t2, PCR_MAJOR_VERSION // get major version
stl t1, PcMinorVersion(s0) // store minor version number
stl t2, PcMajorVersion(s0) // store major version number
ldl t0, LpbThread(s2) // save idle thread in pcr
stl t0, PcIdleThread(s0) //
ldl t0, LpbPanicStack(s2) // save panic stack in pcr
stl t0, PcPanicStack(s0) //
ldl t0, LpbProcessorType(s2) // save processor type in pcr
stl t0, PcProcessorType(s0) //
ldl t0, LpbProcessorRevision(s2) // save processor revision
stl t0, PcProcessorRevision(s0) //
ldl t0, LpbPhysicalAddressBits(s2) // save physical address bits
stl t0, PcPhysicalAddressBits(s0) //
ldl t0, LpbMaximumAddressSpaceNumber(s2) // save max asn
stl t0, PcMaximumAddressSpaceNumber(s0) //
ldl t0, LpbFirstLevelDcacheSize(s2) // save first level dcache size
stl t0, PcFirstLevelDcacheSize(s0) //
ldl t0, LpbFirstLevelDcacheFillSize(s2) // save dcache fill size
stl t0, PcFirstLevelDcacheFillSize(s0) //
ldl t0, LpbFirstLevelIcacheSize(s2) // save first level icache size
stl t0, PcFirstLevelIcacheSize(s0) //
ldl t0, LpbFirstLevelIcacheFillSize(s2) // save icache fill size
stl t0, PcFirstLevelIcacheFillSize(s0) //
ldl t0, LpbSystemType(s2) // save system type
stl t0, PcSystemType(s0) //
ldl t0, LpbSystemType+4(s2) //
stl t0, PcSystemType+4(s0) //
ldl t0, LpbSystemVariant(s2) // save system variant
stl t0, PcSystemVariant(s0) //
ldl t0, LpbSystemRevision(s2) // save system revision
stl t0, PcSystemRevision(s0) //
ldl t0, LpbSystemSerialNumber(s2) // save system serial number
stl t0, PcSystemSerialNumber(s0) //
ldl t0, LpbSystemSerialNumber+4(s2) //
stl t0, PcSystemSerialNumber+4(s0) //
ldl t0, LpbSystemSerialNumber+8(s2) //
stl t0, PcSystemSerialNumber+8(s0) //
ldl t0, LpbSystemSerialNumber+12(s2) //
stl t0, PcSystemSerialNumber+12(s0) //
ldl t0, LpbCycleClockPeriod(s2) // save cycle counter period
stl t0, PcCycleClockPeriod(s0) //
ldl t0, LpbRestartBlock(s2) // save Restart Block address
stl t0, PcRestartBlock(s0) //
ldq t0, LpbFirmwareRestartAddress(s2) // save firmware restart
stq t0, PcFirmwareRestartAddress(s0) //
ldq t0, LpbFirmwareRevisionId(s2) // save firmware revision
stq t0, PcFirmwareRevisionId(s0) //
ldl t0, LpbDpcStack(s2) // save Dpc Stack
stl t0, PcDpcStack(s0) //
ldl t0, LpbPrcb(s2) // save Prcb
stl t0, PcPrcb(s0) //
stl zero, PbDpcRoutineActive(t0) // clear DPC Active flag
stl zero, PcMachineCheckError(s0) // indicate no HAL mchk handler
// Set system service dispatch address limits used by get and set context.
lda t0, KiSystemServiceDispatchStart // set start address of range
stl t0, PcSystemServiceDispatchStart(s0) //
lda t0, KiSystemServiceDispatchEnd // set end address of range
stl t0, PcSystemServiceDispatchEnd(s0) //
// Setup arguments and call kernel initialization routine.
ldl s0, LpbProcess(s2) // get idle process address
ldl s1, LpbThread(s2) // get idle thread address
bis s0, zero, a0 // a0 = idle process address
bis s1, zero, a1 // a1 = idle thread address
ldl a2, LpbKernelStack(s2) // a2 = idle thread stack
ldl a3, LpbPrcb(s2) // a3 = processor block address
LoadByte(a4, PbNumber(a3)) // a4 = processor number
bis s2, zero, a5 // a5 = loader parameter block
bsr ra, KiInitializeKernel // initialize system data
// Control is returned to the idle thread with IRQL at HIGH_LEVEL.
// Lower IRQL level to DISPATCH_LEVEL and set wait IREQL of idle thread.
GET_PROCESSOR_CONTROL_BLOCK_BASE // get prcb
bis v0, zero, s0 // s0 = prcb address
lda s3, PbDpcListHead(s0) // get DPC listhead address
#if !defined(NT_UP)
lda s5, KiDispatcherLock // get address of dispatcher lock
#endif
ldil a0, DISPATCH_LEVEL // get dispatch level IRQL
StoreByte( a0, ThWaitIrql(s1) ) // set wait IRQL of idle thread
bsr ra, KeLowerIrql // lower IRQL
ENABLE_INTERRUPTS // enable interrupts
bis zero, zero, s2 // clear breakin loop counter
bis zero, zero, ra // set bogus RA to stop debugger
br zero, KiIdleLoop
.end KiSystemStartupContinue
// The following code represents the idle thread for a processor. The
// idle thread executes at IRQL DISPATCH_LEVEL and continually polls for work
// to do. Control may be given to this loop either as a result of a return
// from the system initialization routine or as the result of starting up
// another processor in a multiprocessor configuration.
NESTED_ENTRY(KiIdleLoop, ExceptionFrameLength, zero)
lda sp, -ExceptionFrameLength(sp) // allocate context frame
stq ra, ExIntRa(sp) // set bogus RA to stop debugger
stq s0, ExIntS0(sp) // save integer registers s0 - s5
stq s1, ExIntS1(sp) //
stq s2, ExIntS2(sp) //
stq s3, ExIntS3(sp) //
#if !defined(NT_UP)
stq s5, ExIntS5(sp) //
#endif
PROLOGUE_END
lda t0, KiIdleReturn // set return address from SwapContext
stq t0, ExSwapReturn(sp) // directly into exception frame
bsr ra, KiSaveNonVolatileFloatState
// restore registers we need after swap context
KiIdleReturn:
// Lower IRQL back to DISPATCH_LEVEL
ldil a0, DISPATCH_LEVEL
SWAP_IRQL
#if DBG
bis zero, zero, s2 // reset breakin loop counter
#endif
// N.B. The address of the current processor block (s0) is preserved across
// the switch from idle call.
ldq s3, ExIntS3(sp) // restore address of DPC listhead
#if !defined(NT_UP)
ldl t2, KeNumberProcessors // get number of processors
stq t2, ExIntS0(sp) // store number of processors
ldq s5, ExIntS5(sp) // restore address of dispatcher lock
#endif
IdleLoop:
#if DBG
subl s2, 1, s2 // decrement breakin loop counter
bge s2, 5f // if ge, not time for breakin check
ldil s2, 200 * 1000 // set breakin loop counter
bsr ra, KdPollBreakIn // check if breakin is requested
beq v0, 5f // if eq, then no breakin requested
lda a0, DBG_STATUS_CONTROL_C
bsr ra, DbgBreakPointWithStatus
5:
#endif //DBG
// Disable interrupts and check if there is any work in the DPC list
// of the current processor or a target processor.
CheckDpcList:
ENABLE_INTERRUPTS // give interrupts a chance
DISABLE_INTERRUPTS // to interrupt spinning
// Process the deferred procedure call list for the current processor.
ldl t0, PbDpcQueueDepth(s0) // get current queue depth
beq t0, CheckNextThread // if eq, DPC list is empty
// Clear dispatch interrupt.
ldil a0, DISPATCH_LEVEL
ldl t0, PbSoftwareInterrupts(s0) // clear any pending SW interrupts.
bic t0, a0, t1
stl t1, PbSoftwareInterrupts(s0)
DEASSERT_SOFTWARE_INTERRUPT // clear any PAL-requested interrupts.
bis zero, zero, s2 // clear breakin loop counter
bsr ra, KiRetireDpcList
// Check if a thread has been selected to run on this processor.
CheckNextThread:
ldl a0, PbNextThread(s0) // get address of next thread object
beq a0, IdleProcessor // if eq, no thread selected
// A thread has been selected for execution on this processor. Acquire
// dispatcher database 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.
// N.B. If the dispatcher database lock cannot be obtained immediately,
// then attempt to process another DPC rather than spinning on the
// dispatcher database lock.
#if !defined(NT_UP)
130:
ldl_l t0, 0(s5) // get current lock value
bis s5, zero, t1 // set lock ownership value
bne t0, CheckDpcList // if ne, spin lock owned, go try the DPC list again
stl_c t1, 0(s5) // set spin lock owned
beq t1, 135f // if eq, store conditional failed
mb // synchronize subsequent reads after
// the spinlock is acquired
#endif
// Raise IRQL to sync level and re-enable interrupts
ldl a0, KiSynchIrql
SWAP_IRQL
ENABLE_INTERRUPTS
ldl s2, PbNextThread(s0) // get address of next thread object
ldl s1, PbIdleThread(s0) // get address of current thread
stl zero, PbNextThread(s0) // clear next thread address
stl s2, PbCurrentThread(s0) // set address of current thread object
// Set new thread's state to running. Note this must be done
// under the dispatcher lock so that KiSetPriorityThread sees
// the correct state.
ldil t0, Running
StoreByte( t0, ThState(s2) )
#if !defined(NT_UP)
// Acquire the context swap lock so the address space of the old thread
// cannot be deleted and then release the dispatcher database lock. In
// this case the old thread is the idle thread, but the context swap code
// releases the context swap lock so it must be acquired.
// N.B. This lock is used to protect the address space until the context
// switch has sufficiently progressed to the point where the address
// space is no longer needed. This lock is also acquired by the reaper
// thread before it finishes thread termination.
lda t0, KiContextSwapLock // get context swap lock address
140:
ldl_l t1, 0(t0) // get current lock value
bis t0, zero, t2 // set ownership value
bne t1, 145f // if ne, lock already owned
stl_c t2, 0(t0) // set lock ownership value
beq t2, 145f // if eq, store conditional failed
mb // synchronize reads and writes
stl zero, 0(s5) // set lock not owned
#endif
bsr ra, SwapFromIdle // swap context to new thread
// Note control returns directly from SwapFromIdle to the top
// of the loop (KiIdleReturn) since SwapContext gets ra directly from ExSwapReturn(sp)
// which was explicitly set when the idle loop was originally entered.
IdleProcessor:
// 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 management can
// be performed.
// N.B. The HAL is called with interrupts disabled. The HAL will return
// with interrupts enabled.
bsr ra, HalProcessorIdle // notify HAL of idle state
br zero, IdleLoop // restart idle loop
#if !defined(NT_UP)
135:
// Conditional store of dispatcher lock failed. Retry. Do not
// spin in cache here. If the lock is owned, we want to check
// the DPC list again.
ENABLE_INTERRUPTS
DISABLE_INTERRUPTS
br zero, 130b
145:
ldl t1, 0(t0) // spin in cache until lock free
beq t1, 140b // retry spin lock
br zero, 145b
#endif
.end KiSwapThread
SBTTL("Retire Deferred Procedure Call List")
// Routine Description:
// This routine is called to retire the specified deferred procedure
// call list. DPC routines are called using the idle thread (current)
// stack.
// N.B. Interrupts must be disabled and the DPC list lock held on entry
// to this routine. Control is returned to the caller with the same
// conditions true.
// Arguments:
// s0 - Address of the processor control block.
// Return value:
// None.
.struct 0
DpRa: .space 8 // return address
.space 8 // fill
#if DBG
DpStart:.space 8 // DPC start time in ticks
DpFunct:.space 8 // DPC function address
DpCount:.space 8 // interrupt count at start of DPC
DpTime: .space 8 // interrupt time at start of DPC
#endif
DpcFrameLength: // DPC frame length
NESTED_ENTRY(KiRetireDpcList, DpcFrameLength, zero)
lda sp, -DpcFrameLength(sp) // allocate stack frame
stq ra, DpRa(sp) // save return address
PROLOGUE_END
5:
stl sp, PbDpcRoutineActive(s0) // set DPC routine active
// Process the DPC list.
10: ldl t0, PbDpcQueueDepth(s0) // get current DPC queue depth
beq t0, 60f // if eq, list is empty
lda t2, PbDpcListHead(s0) // compute DPC list head address
20:
#if !defined(NT_UP)
ldl_l t1, PbDpcLock(s0) // get current lock value
bis s0, zero, t3 // set lock ownership value
bne t1, 25f // if ne, spin lock owned
stl_c t3, PbDpcLock(s0) // set spin lock owned
beq t3, 25f // if eq, store conditional failed
mb
ldl t0, PbDpcQueueDepth(s0) // get current DPC queue depth
beq t0, 50f // if eq, DPC list is empty
#endif
ldl a0, LsFlink(t2) // get address of next entry
ldl t1, LsFlink(a0) // get address of next entry
lda a0, -DpDpcListEntry(a0) // compute address of DPC object
stl t1, LsFlink(t2) // set address of next in header
stl t2, LsBlink(t1) // set address of previous in next
ldl a1, DpDeferredContext(a0) // get deferred context argument
ldl a2, DpSystemArgument1(a0) // get first system argument
ldl a3, DpSystemArgument2(a0) // get second system argument
ldl t1, DpDeferredRoutine(a0) // get deferred routine address
stl zero, DpLock(a0) // clear DPC inserted state
subl t0, 1, t0 // decrement DPC queue depth
stl t0, PbDpcQueueDepth(s0) // update DPC queue depth
#if !defined(NT_UP)
mb // synchronize previous writes
stl zero, PbDpcLock(s0) // set spinlock not owned
#endif
ENABLE_INTERRUPTS // enable interrupts
jsr ra, (t1)
DISABLE_INTERRUPTS
br zero, 10b
// Unlock DPC list and clear DPC active.
50:
#if !defined(NT_UP)
mb // synchronize previous writes
stl zero, PbDpcLock(s0) // set spin lock not owned
#endif
60:
stl zero, PbDpcRoutineActive(s0) // clear DPC routine active
stl zero, PbDpcInterruptRequested(s0) // clear DPC interrupt requested
// Check one last time that the DPC list is empty. This is required to
// close a race condition with the DPC queuing code where it appears that
// a DPC routine is active (and thus an interrupt is not requested), but
// this code has decided the DPC list is empty and is clearing the DPC
// active flag.
#if !defined(NT_UP)
mb
#endif
ldl t0, PbDpcQueueDepth(s0) // get current DPC queue depth
beq t0, 70f // if eq, DPC list is still empty
stl sp, PbDpcRoutineActive(s0) // set DPC routine active
lda t2, PbDpcListHead(s0) // compute DPC list head address
br zero, 20b
70:
ldq ra, DpRa(sp) // restore RA
lda sp, DpcFrameLength(sp) // deallocate stack frame
ret zero, (ra) // return
#if !defined(NT_UP)
25:
ldl t1, PbDpcLock(s0) // spin in cache until lock free
beq t1, 20b // retry spinlock
br zero, 25b
#endif
.end KiRetireDpcList