A2osX/SYS/KERNEL.S.IRQ.txt

NEW
PREFIX /A2OSX.BUILD
AUTO 4,1
*--------------------------------------
* called directly by IRQ Vector $FFFE in AuxLC
* Must keep:
*  A,X,Y
*   SETREADAUX
*  if we are here, Aux ZP/Stack already On
* Exit with RTI
* if A2osX Drivers cannot clear IRQ, 
* must call regular System Handler
*--------------------------------------
MSLOT			.EQ $7f8
*--------------------------------------
K.IrqHAuxLC.BRK	jmp K.IrqHAuxLC.6
*--------------------------------------
K.IrqHAuxLC		cld

				sec
				
				sta K.IrqHAuxLC.6+1
				pla
				pha
				and #$10				BRK?
				bne K.IrqHAuxLC.BRK
				
				stx	K.IrqHAuxLC.5+1
				sty K.IrqHAuxLC.4+1
				
				lda $fe					Save 2 bytes in ZP
				pha
				lda $ff
				pha
				
				lda RDREADAUX
				pha
				sta CLRREADAUX			Make sure we can access Dev.Table
				
				lda RDWRITEAUX
				pha
				sta CLRWRITEAUX			Driver may R/W in screen holes
				
				lda MSLOT				Save MSLOT
				pha
				
				lda RDCXROM
				pha
				sta CLRCXROM			Enable access to slot C800 space
				
K.IrqHAuxLC.JSR	jsr K.IrqH.DEV			SELF MODIFIED
					
				ldx #CLRCXROM

				pla						Get CXROM State
				bpl .3
				inx
.3				sta $C000,x				
				
				pla						Get back MSLOT
				sta MSLOT
				sta K.IrqHAuxLC.2+2

				and #$F0
				eor #$C0				....mmm...not looking link Cn....
				bne K.IrqHAuxLC.3
				sta	$CFFF				Release $C800			
				
K.IrqHAuxLC.2	lda $ff00				SELF MODIFIED				
				
K.IrqHAuxLC.3	pla						Must keep Carry
				bpl .1
				
				sta SETWRITEAUX
				
.1				pla
				bpl .2
				
				sta SETREADAUX
				
.2				pla
				sta $ff
				pla
				sta $fe
				
				bvc K.IrqHAuxLC.4		if V, skip task switching
				
				tsx
				txa
				eor #$FC				Only LO,HI & P on stack
				beq K.IrqHAuxLC.4		we are in kernel CORE.Run
				
				php						
				php						make room for 2 additional bytes

				tsx
				
				lda $104,x				get RTI PC LO
				bne .3
				dec $105,x				adjust RTI PC HI

.3				dec $104,x				back one byte, to make it a "RTS" return adddress 

				lda $103,x				get IRQ pushed P
				sta $101,x				down 2 bytes				

				lda #A2osX.SLEEP		make a RTI like "jsr A2osX.SLEEP"
				sta $102,x
				lda /A2osX.SLEEP		with RTS=PC IRQ-1
				sta $103,x

				lda #$A0+'S
				eor SYS.BASL0+37
				sta SYS.BASL0+37
				
K.IrqHAuxLC.4	ldy #$ff				Self Modified
K.IrqHAuxLC.5	ldx #$ff				Self Modified
K.IrqHAuxLC.6	lda #$ff				Self Modified
				bcc K.IrqHAuxLC.8
				
				dec IRQ.SkipA2osX		Make regular ProDOS IRQ manager skip A2osX
K.IrqHAuxLC.JMP	jmp $FFFF				SELF MODIFIED	Not handled, pass to ProDOS
K.IrqHAuxLC.8	rti				
*--------------------------------------
* Called by :
*  - Kernel K.IrqHAuxLC
*  - ProDOS IRQ Manager (GP)
*--------------------------------------
K.IrqH.TCLOCK	ldy IRQ.VBL.n0
				
				lda $c080,y
				and #$20
				beq K.IrqH.DEV
				
				lda $c080,y
				lda $c088,y
				
				bra K.IrqH.Switch
*--------------------------------------
K.IrqH.VBL
K.IrqH.VBL.MSM	jsr $FFFF				SELF MODIFIED,SERVEMOUSE
				bcs K.IrqH.DEV			Not From Mouse
				
				ldx IRQ.VBL.0n
				lda MOUSESTSx,x
				and #MOUSESTSx.INTVBL	IRQ was caused by VBL ?
				beq K.IrqH.DEV
				
				ldx K.IrqH.VBL.MRM+2	$Cn
				ldy IRQ.VBL.n0
K.IrqH.VBL.MRM	jsr $FFFF				SELF MODIFIED,READMOUSE
*--------------------------------------
K.IrqH.Switch	inc IRQ.Tick

				dec CORE.CPUStat
				bne .2
				
				lda #100
				sta CORE.CPUStat
				
				stz CORE.InKernelStat
				
				ldx CORE.PSCount
				
.1				stz PS.Table.Stat-1,x
				dex
				bne .1
				
.2				lda IRQ.InKernel		keep V flag set
				bpl .3
				
				inc CORE.InKernelStat
	
.9				clv
				clc
				rts
				
.3				ldx CORE.PSIndex
				inc PS.Table.Stat-1,x

				bit A2osX.F				A2osX.F.PMODE .EQ %01000000
				bvc .8

				lda (pPs)
				and #S.PS.F.DOEVENT
				bne .9
				
.8				clc						exit with V flag set
				rts
*--------------------------------------			
K.IrqH.DEV		ldx #0
				
.1				lda Dev.Table+1,x
				beq .2
				
				sta $ff
				lda Dev.Table,x
				sta $fe
				
				ldy #S.NODE.DEV.DRVPTR
				lda ($fe),y
				pha
				
				iny
				lda ($fe),y
				sta $ff
				pla
				sta $fe
				
				ldy #IOCTL.IRQ+4+1		
				lda ($fe),y
				cmp /A2osX.BADCALL
				beq .2
				
				sta .10+2
				dey
				lda ($fe),y
				sta .10+1
				
.10				jsr $ffff				SELF MODIFIED
				
				plx
				bcc .8					CC, IRQ cleared by device
				
.2				inx
				inx
				
.3				cpx DevMgr.DevCnt
				bne .1
				
				sec
				
.8				clv						clear V (no task switching)
				rts
*--------------------------------------
MAN
SAVE /A2OSX.SRC/SYS/KERNEL.S.IRQ
LOAD /A2OSX.SRC/SYS/KERNEL.S
ASM