powermac-rom/NanoKernel/NKIntHandlers.s

;	AUTO-GENERATED SYMBOL LIST

########################################################################

	_align 6
IntExternal0
	mfsprg	r1, 0							; Init regs and increment ctr
	stw		r0, KDP.r0(r1)
	stw		r2, KDP.r2(r1)
	lwz		r2, KDP.NKInfo.ExternalIntCount(r1)
	stw		r3, KDP.r3(r1)
	addi	r2, r2, 1
	stw		r2, KDP.NKInfo.ExternalIntCount(r1)

	mfmsr	r2								; Save a self-ptr to FF880000... why?
	lis		r3, 0xFF88
	_bset	r0, r2, bitMsrDR
	stw		r4, KDP.r4(r1)
	stw		r5, KDP.r5(r1)
	mfsrr0	r4
	mfsrr1	r5
	mtmsr	r0
	stw		r3, 0(r3)
	mtmsr	r2
	mtsrr0	r4
	mtsrr1	r5
	lwz		r4, KDP.r4(r1)
	lwz		r5, KDP.r5(r1)

	lwz		r2, KDP.DebugIntPtr(r1)			; Query the shared mem (debug?) for int num
	mfcr	r0
	lha		r2, 0(r2)
	lwz		r3, KDP.EmuIntLevelPtr(r1)
	rlwinm.	r2, r2, 0, 0x80000007
	ori		r2, r2, 0x8000
	sth		r2, 0(r3)
	mfsprg	r2, 2
	lwz		r3, KDP.r3(r1)
	mtlr	r2
	beq		@clear							; 0 -> clear interrupt
	bgt		@return							; negative -> no interrupt flag
											; positive -> post interrupt

	lwz		r2, KDP.PostIntMaskInit(r1)		; Post an interrupt via Cond Reg
	or		r0, r0, r2

@return
	mtcr	r0								; Set CR and return
	lwz		r0, KDP.r0(r1)
	lwz		r2, KDP.r2(r1)
	mfsprg	r1, 1
	rfi

@clear
	lwz		r2, KDP.ClearIntMaskInit(r1)	; Clear an interrupt via Cond Reg
	and		r0, r0, r2
	b		@return

########################################################################

	_align 6
IntLookupTable
	dc.b	0, 1, 2, 2, 4, 4, 4, 4
	dc.b	3, 3, 3, 3, 4, 4, 4, 4
	dc.b	4, 4, 4, 4, 4, 4, 4, 4
	dc.b	4, 4, 4, 4, 4, 4, 4, 4
	dc.b	7, 7, 7, 7, 7, 7, 7, 7
	dc.b	7, 7, 7, 7, 7, 7, 7, 7
	dc.b	7, 7, 7, 7, 7, 7, 7, 7
	dc.b	7, 7, 7, 7, 7, 7, 7, 7

	_align 6
IntExternal1
	mfsprg	r1, 0							; Init regs and increment ctr
	stw		r0, KDP.r0(r1)
	stw		r2, KDP.r2(r1)
	lwz		r2, KDP.NKInfo.ExternalIntCount(r1)
	stw		r3, KDP.r3(r1)
	addi	r2, r2, 1
	stw		r2, KDP.NKInfo.ExternalIntCount(r1)

	lis		r2, 0x50F3						; Query OpenPIC at 50F2A000
	mfmsr	r3
	_bset	r0, r3, bitMsrDR
	stw		r4, KDP.r4(r1)
	stw		r5, KDP.r5(r1)
	mfsrr0	r4
	mfsrr1	r5
	mtmsr	r0
	li		r0, 0xC0
	stb		r0, -0x6000(r2)
	eieio
	lbz		r0, -0x6000(r2)
	mtmsr	r3
	mtsrr0	r4
	mtsrr1	r5
	lwz		r4, KDP.r4(r1)
	lwz		r5, KDP.r5(r1)

	lwz		r3, KDP.NKCodePtr(r1)			; Loop that number up in the table
	rlwimi	r3, r0, 0, 0x0000003F
	lbz		r2, IntLookupTable-NKTop(r3)
	mfcr	r0
	lwz		r3, KDP.EmuIntLevelPtr(r1)
	clrlwi.	r2, r2, 29
	sth		r2, 0(r3)
	mfsprg	r2, 2
	lwz		r3, KDP.r3(r1)
	mtlr	r2
	beq		@clear							; 0 -> clear interrupt
											; nonzero -> post interrupt

	lwz		r2, KDP.PostIntMaskInit(r1)		; Post an interrupt via Cond Reg
	or		r0, r0, r2

@return
	mtcr	r0								; Set CR and return
	lwz		r0, KDP.r0(r1)
	lwz		r2, KDP.r2(r1)
	mfsprg	r1, 1
	rfi

@clear
	lwz		r2, KDP.ClearIntMaskInit(r1)	; Clear an interrupt via Cond Reg
	and		r0, r0, r2
	b		@return

########################################################################

	_align 6
IntExternal2
	mfsprg	r1, 0							; Init regs and increment ctr
	stw		r0, KDP.r0(r1)
	stw		r2, KDP.r2(r1)
	lwz		r2, KDP.NKInfo.ExternalIntCount(r1)
	stw		r3, KDP.r3(r1)
	addi	r2, r2, 1
	stw		r2, KDP.NKInfo.ExternalIntCount(r1)

	lis		r2, 0xF300						; Query OpenPIC at F3000028/C
	mfmsr	r0
	_bset	r3, r0, bitMsrDR
	stw		r4, KDP.r4(r1)
	stw		r5, KDP.r5(r1)
	mfsrr0	r4
	mfsrr1	r5
	mtmsr	r3
	lis		r3, 0x8000
	stw		r3, 0x28(r2)
	eieio
	lwz		r3, 0x2C(r2)
	mtmsr	r0
	mtsrr0	r4
	mtsrr1	r5
	lwz		r4, KDP.r4(r1)
	lwz		r5, KDP.r5(r1)

	mfcr	r0
											; Interpret OpenPic result:
	rlwinm.	r2, r3, 0, 11, 11				; bit 11 -> 7
	li		r2, 7
	bne		@gotnum

	rlwinm	r2, r3, 0, 15, 16				; bit 15-16/21/31 -> 4
	rlwimi.	r2, r3, 0, 21, 31
	li		r2, 4
	bne		@gotnum

	rlwinm.	r2, r3, 0, 18, 18				; bit 18 -> 3
	li		r2, 3
	bne		@gotnum

	andis.	r2, r3, 0x7FEA					; bit 1-10/12/14/19-20 -> 2
	rlwimi.	r2, r3, 0, 19, 20
	li		r2, 2
	bne		@gotnum

	extrwi.	r2, r3, 1, 13					; bit 13 -> 1
											; else -> 0

@gotnum
	lwz		r3, KDP.EmuIntLevelPtr(r1)
	sth		r2, 0(r3)
	mfsprg	r2, 2
	lwz		r3, KDP.r3(r1)
	mtlr	r2
	beq		@clear							; 0 -> clear interrupt
											; nonzero -> post interrupt

	lwz		r2, KDP.PostIntMaskInit(r1)		; Post an interrupt via Cond Reg
	or		r0, r0, r2

@return
	mtcr	r0								; Set CR and return
	lwz		r0, KDP.r0(r1)
	lwz		r2, KDP.r2(r1)
	mfsprg	r1, 1
	rfi

@clear
	lwz		r2, KDP.ClearIntMaskInit(r1)	; Clear an interrupt via Cond Reg
	and		r0, r0, r2
	b		@return

########################################################################

;	Increment the Sys/Alt CPU clocks, and the Dec-int counter
	_align 6
DecrementerIntSys
	mfsprg	r1, 0
	stmw	r2, KDP.r2(r1)
	mfdec	r31
	lwz		r30, KDP.OtherContextDEC(r1)

DecCommon ; DEC for Alternate=r30, System=r31
	mfxer	r29							; we will do carries

	lwz		r28, KDP.ProcInfo.DecClockRateHz(r1)
	stw		r28, KDP.OtherContextDEC(r1)
	mtdec	r28							; reset Sys and Alt decrementers

	subf	r31, r31, r28				; System ticks actually elapsed
	subf	r30, r30, r28				; Alternate ticks actually elapsed

	lwz		r28, KDP.NKInfo.SysContextCpuTime+4(r1)
	lwz		r27, KDP.NKInfo.SysContextCpuTime(r1)
	addc	r28, r28, r31
	addze	r27, r27
	stw		r28, KDP.NKInfo.SysContextCpuTime+4(r1)
	stw		r27, KDP.NKInfo.SysContextCpuTime(r1)

	lwz		r28, KDP.NKInfo.AltContextCpuTime+4(r1)
	lwz		r27, KDP.NKInfo.AltContextCpuTime(r1)
	addc	r28, r28, r30
	addze	r27, r27
	stw		r28, KDP.NKInfo.AltContextCpuTime+4(r1)
	stw		r27, KDP.NKInfo.AltContextCpuTime(r1)

	mtxer	r29

	stw		r0, KDP.r0(r1)
	mfsprg	r31, 1
	stw		r31, KDP.r1(r1)

	lwz		r31, KDP.NKInfo.DecrementerIntCount(r1)
	addi	r31, r31, 1
	stw		r31, KDP.NKInfo.DecrementerIntCount(r1)

	lmw		r27, KDP.r27(r1)
	mfsprg	r1, 2
	mtlr	r1
	mfsprg	r1, 1
	rfi

DecrementerIntAlt
	mfsprg	r1, 0
	stmw	r2, KDP.r2(r1)
	lwz		r31, KDP.OtherContextDEC(r1)
	mfdec	r30
	b		DecCommon

########################################################################

	_align 6
DataStorageInt
	mfsprg	r1, 0
	stmw	r2, KDP.r2(r1)
	mfsprg	r11, 1
	stw		r0, KDP.r0(r1)
	stw		r11, KDP.r1(r1)

	mfsrr0	r10
	mfsrr1	r11
	mfsprg	r12, 2
	mfcr	r13

	mfmsr	r14
	_bset	r15, r14, bitMsrDR
	mtmsr	r15
	lwz		r27, 0(r10)						; r27 = INSTRUCTION
	mtmsr	r14

EmulateDataAccess
	rlwinm.	r18, r27, 18, 25, 29			; r16 = 4 * rA (r0 wired to 0)
	lwz		r25, KDP.RetryCodePtr(r1)
	li		r21, 0
	beq		@r0
	lwzx	r18, r1, r18					; r16 = contents of rA
@r0
	andis.	r26, r27, 0xec00				; intended to extract the major opcode? seems wrong though!
	lwz		r16, KDP.Flags(r1)
	mfsprg	r24, 3
	rlwinm	r17, r27, 0, 6, 15				; r17 = rS/D and rA fields
	rlwimi	r16, r16, 27, 26, 26
	bge		@xform

;dform
	rlwimi	r25, r27, 7, 26, 29				; opcode >= 32
	rlwimi	r25, r27, 12, 25, 25
	lwz		r26, MROptabD - MRTop(r25)	; table of 4b elements, index = major opcode bits 51234 (this is the last quarter of MROptabX)
	extsh	r23, r27						; r23 = register offset field, sign-extended
	rlwimi	r25, r26, 26, 22, 29
	mtlr	r25								; dest = r25 = first of two function ptrs in table entry
	mtcr	r26								; using the flags in the arbitrary upper 16 bits of the table entry?
	add		r18, r18, r23					; r18 = effective address attempted by instruction
	rlwimi	r17, r26, 6, 26, 5				; r17 = pretend X-form inst with: maj opcode (from tbl), rS/D and RA (from inst), min opcode (from tbl)
	blr

@xform										; opcode <= 31
	rlwimi	r25, r27, 27, 26, 29
	rlwimi	r25, r27, 0, 25, 25
	rlwimi	r25, r27, 6, 23, 24
	lwz		r26, MROptabX - MRTop(r25)	; table of 4b elements, index = minor (x-form) opcode bits 8940123
	rlwinm	r23, r27, 23, 25, 29			; r23 = 4 * rB
	rlwimi	r25, r26, 26, 22, 29
	mtlr	r25								; dest = r25 = first of two function ptrs in table entry
	mtcr	r26
	lwzx	r23, r1, r23					; get rB from saved registers
	rlwimi	r17, r26, 6, 26, 5				; r17 = pretend X-form inst with: maj opcode (from tbl), rS/D and RA (from inst), min opcode (from tbl)
	add		r18, r18, r23					; r18 = effective address attempted by instruction
	bclr	BO_IF_NOT, 13
	neg		r23, r23
	add		r18, r18, r23
	blr

########################################################################

	_align 6
AlignmentInt
	mfsprg	r1, 0
	stmw	r2, KDP.r2(r1)

	lwz		r11, KDP.NKInfo.MisalignmentCount(r1)
	addi	r11, r11, 1
	stw		r11, KDP.NKInfo.MisalignmentCount(r1)

	mfsprg	r11, 1
	stw		r0, KDP.r0(r1)
	stw		r11, KDP.r1(r1)

	mfsrr0	r10
	mfsrr1	r11
	mfsprg	r12, 2
	mfcr	r13
	mfsprg	r24, 3
	mfdsisr	r27
	mfdar	r18

	extrwi.	r21, r27, 2, 15			; evaluate hi two bits of XO (or 0 for d-form?)
	lwz		r25, KDP.RetryCodePtr(r1)
	rlwinm	r17, r27, 16, 0x03FF0000
	lwz		r16, KDP.Flags(r1)
	rlwimi	r25, r27, 24, 23, 29	; add constant fields from dsisr (*4) to FDP
	rlwimi	r16, r16, 27, 26, 26	; copy FlagSE to FlagTrace
	bne		@X_form

	;	D- or DS-form (immediate-indexed) instruction
	lwz		r26, MROptabD - MRTop(r25)	; use upper quarter of table
	mfmsr	r14
	rlwimi	r25, r26, 26, 22, 29	; third byte of lookup value is a /4 code offset in FDP
	mtlr	r25						; so get ready to go there
	_bset	r15, r14, bitMsrDR
	mtcr	r26
	rlwimi	r17, r26, 6, 26, 5		; wrap some shite around the register values
	blr

@X_form
	;	X-form (register-indexed) instruction
	lwz		r26, MROptabX - MRTop(r25)
	mfmsr	r14
	rlwimi	r25, r26, 26, 22, 29
	mtlr	r25
	_bset	r15, r14, bitMsrDR
	mtcr	r26
	rlwimi	r17, r26, 6, 26, 5
	bclr	BO_IF_NOT, 12
	mtmsr	r15
	lwz		r27, 0(r10)
	mtmsr	r14
	blr

########################################################################

	INCLUDE 'NKMemRetry.s'

########################################################################

InstStorageInt
	bl		LoadInterruptRegisters

	andis.	r8, r11, 0x4020			; what the hell are these MSR bits?
	beq		major_0x039dc_0x14

	stmw	r14, KDP.r14(r8)
	mr		r27, r10
	bl		PutPTE
	bne		@not_in_htab

	mfsprg	r24, 3
	mfmsr	r14
	_bset	r15, r14, bitMsrDR
	addi	r23, r1, KDP.VecTblMemRetry
	mtsprg	3, r23
	mr		r19, r10
	mtmsr	r15
	lbz		r23, 0(r19)
	sync
	mtmsr	r14
	mtsprg	3, r24
	lmw		r14, KDP.r14(r1)
	b		IntReturn

@not_in_htab
	lmw		r14, KDP.r14(r1)
	li		r8, ecInstPageFault
	blt		Exception
	li		r8, ecInstInvalidAddress
	b		Exception

major_0x039dc_0x14
	andis.	r8, r11, 0x800
	li		r8, ecInstSupAccessViolation
	bne		Exception
	li		r8, ecInstHardwareFault
	b		Exception

########################################################################

MachineCheckInt
	bl		LoadInterruptRegisters
	li		r8, ecMachineCheck
	b		Exception