290 lines
9.0 KiB
ArmAsm
290 lines
9.0 KiB
ArmAsm
// TITLE("Miscellaneous Kernel Functions")
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//++
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//
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// Copyright (c) 1990 Microsoft Corporation
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//
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// Module Name:
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//
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// misc.s
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//
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// Abstract:
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//
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// This module implements machine dependent miscellaneous kernel functions.
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// Functions are provided to request a software interrupt, continue thread
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// execution, flush the write buffer, and perform last chance exception
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// processing.
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//
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// Author:
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//
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// David N. Cutler (davec) 31-Mar-1990
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//
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// Environment:
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//
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// Kernel mode only.
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//
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// Revision History:
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//
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//--
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#include "ksmips.h"
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SBTTL("Request Software Interrupt")
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//++
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//
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// VOID
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// KiRequestSoftwareInterrupt (
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// ULONG RequestIrql
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// )
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//
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// Routine Description:
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//
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// This function requests a software interrupt at the specified IRQL
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// level.
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//
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// Arguments:
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//
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// RequestIrql (a0) - Supplies the request IRQL value.
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//
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// Return Value:
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//
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// None.
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//
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//--
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LEAF_ENTRY(KiRequestSoftwareInterrupt)
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li t0,1 << (CAUSE_INTPEND - 1) // get partial request mask value
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DISABLE_INTERRUPTS(t1) // disable interrupts
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.set noreorder
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.set noat
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mfc0 t2,cause // get exception cause register
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sll t0,t0,a0 // shift request mask into position
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or t2,t2,t0 // merge interrupt request mask
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mtc0 t2,cause // set exception cause register
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.set at
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.set reorder
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ENABLE_INTERRUPTS(t1) // enable interrupts
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j ra // return
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.end KiRequestSoftwareInterrupt
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SBTTL("Continue Execution System Service")
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//++
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//
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// NTSTATUS
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// NtContinue (
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// IN PCONTEXT ContextRecord,
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// IN BOOLEAN TestAlert
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// )
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//
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// Routine Description:
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//
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// This routine is called as a system service to continue execution after
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// an exception has occurred. Its functions is to transfer information from
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// the specified context record into the trap frame that was built when the
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// system service was executed, and then exit the system as if an exception
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// had occurred.
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//
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// Arguments:
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//
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// ContextRecord (a0) - Supplies a pointer to a context record.
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//
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// TestAlert (a1) - Supplies a boolean value that specifies whether alert
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// should be tested for the previous processor mode.
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//
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// N.B. Register s8 is assumed to contain the address of a trap frame.
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//
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// Return Value:
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//
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// Normally there is no return from this routine. However, if the specified
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// context record is misaligned or is not accessible, then the appropriate
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// status code is returned.
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//
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//--
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NESTED_ENTRY(NtContinue, ExceptionFrameLength, zero)
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subu sp,sp,ExceptionFrameLength // allocate exception frame
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sw ra,ExIntRa(sp) // save return address
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PROLOGUE_END
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//
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// Save the nonvolatile machine state so that it can be restored by exception
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// exit if it is not overwritten by the specified context record.
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//
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sd s0,TrXIntS0(s8) // save integer registers s0 - s7
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sd s1,TrXIntS1(s8) //
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sd s2,TrXIntS2(s8) //
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sd s3,TrXIntS3(s8) //
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sd s4,TrXIntS4(s8) //
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sd s5,TrXIntS5(s8) //
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sd s6,TrXIntS6(s8) //
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sd s7,TrXIntS7(s8) //
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li t0,TRUE // set saved s-registers flag
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sb t0,TrSavedFlag(s8) //
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sdc1 f20,ExFltF20(sp) // save floating registers f20 - f31
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sdc1 f22,ExFltF22(sp) //
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sdc1 f24,ExFltF24(sp) //
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sdc1 f26,ExFltF26(sp) //
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sdc1 f28,ExFltF28(sp) //
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sdc1 f30,ExFltF30(sp) //
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//
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// Transfer information from the context frame to the exception and trap
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// frames.
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//
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sb a1,ExceptionFrameLength + 4(sp) // save test alert argument
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move a1,sp // set address of exception frame
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move a2,s8 // set address of trap frame
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jal KiContinue // transfer context to kernel frames
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//
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// If the kernel continuation routine returns success, then exit via the
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// exception exit code. Otherwise return to the system service dispatcher.
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//
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bne zero,v0,20f // if ne, transfer failed
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//
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// Check to determine if alert should be tested for the previous processor
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// mode and restore the previous mode in the thread object.
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//
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lw t0,KiPcr + PcCurrentThread(zero) // get current thread address
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lbu t1,ExceptionFrameLength + 4(sp) // get test alert argument
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lw t2,TrTrapFrame(s8) // get old trap frame address
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lbu t3,TrPreviousMode(s8) // get old previous mode
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lbu a0,ThPreviousMode(t0) // get current previous mode
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sw t2,ThTrapFrame(t0) // restore old trap frame address
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sb t3,ThPreviousMode(t0) // restore old previous mode
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beq zero,t1,10f // if eq, don't test for alert
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jal KeTestAlertThread // test alert for current thread
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//
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// Exit the system via exception exit which will restore the nonvolatile
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// machine state.
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//
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10: j KiExceptionExit // finish in exception exit
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//
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// Context record is misaligned or not accessible.
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//
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20: lw ra,ExIntRa(sp) // restore return address
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addu sp,sp,ExceptionFrameLength // deallocate stack frame
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j ra // return
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.end NtContinue
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SBTTL("Raise Exception System Service")
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//++
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//
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// NTSTATUS
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// NtRaiseException (
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// IN PEXCEPTION_RECORD ExceptionRecord,
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// IN PCONTEXT ContextRecord,
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// IN BOOLEAN FirstChance
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// )
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//
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// Routine Description:
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//
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// This routine is called as a system service to raise an exception.
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// The exception can be raised as a first or second chance exception.
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//
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// Arguments:
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//
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// ExceptionRecord (a0) - Supplies a pointer to an exception record.
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//
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// ContextRecord (a1) - Supplies a pointer to a context record.
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//
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// FirstChance (a2) - Supplies a boolean value that determines whether
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// this is the first (TRUE) or second (FALSE) chance for dispatching
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// the exception.
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//
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// N.B. Register s8 is assumed to contain the address of a trap frame.
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//
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// Return Value:
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//
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// Normally there is no return from this routine. However, if the specified
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// context record or exception record is misaligned or is not accessible,
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// then the appropriate status code is returned.
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//
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//--
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NESTED_ENTRY(NtRaiseException, ExceptionFrameLength, zero)
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subu sp,sp,ExceptionFrameLength // allocate exception frame
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sw ra,ExIntRa(sp) // save return address
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PROLOGUE_END
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//
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// Save the nonvolatile machine state so that it can be restored by exception
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// exit if it is not overwritten by the specified context record.
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//
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sd s0,TrXIntS0(s8) // save integer registers s0 - s7
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sd s1,TrXIntS1(s8) //
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sd s2,TrXIntS2(s8) //
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sd s3,TrXIntS3(s8) //
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sd s4,TrXIntS4(s8) //
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sd s5,TrXIntS5(s8) //
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sd s6,TrXIntS6(s8) //
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sd s7,TrXIntS7(s8) //
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li t0,TRUE // set saved s-registers flag
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sb t0,TrSavedFlag(s8) //
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sdc1 f20,ExFltF20(sp) // save floating registers f20 - f31
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sdc1 f22,ExFltF22(sp) //
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sdc1 f24,ExFltF24(sp) //
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sdc1 f26,ExFltF26(sp) //
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sdc1 f28,ExFltF28(sp) //
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sdc1 f30,ExFltF30(sp) //
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//
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// Call the raise exception kernel routine which will marshall the arguments
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// and then call the exception dispatcher.
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//
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sw a2,ExArgs + 16(sp) // set first chance argument
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move a2,sp // set address of exception frame
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move a3,s8 // set address of trap frame
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jal KiRaiseException // call raise exception routine
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//
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// If the raise exception routine returns success, then exit via the exception
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// exit code. Otherwise return to the system service dispatcher.
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//
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lw t0,KiPcr + PcCurrentThread(zero) // get current thread address
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lw t1,TrTrapFrame(s8) // get old trap frame address
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bne zero,v0,10f // if ne, dispatch not successful
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sw t1,ThTrapFrame(t0) // restore old trap frame address
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//
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// Exit the system via exception exit which will restore the nonvolatile
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// machine state.
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//
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j KiExceptionExit // finish in exception exit
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//
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// The context or exception record is misaligned or not accessible, or the
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// exception was not handled.
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//
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10: lw ra,ExIntRa(sp) // restore return address
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addu sp,sp,ExceptionFrameLength // deallocate stack frame
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j ra // return
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.end NtRaiseException
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