A2osX/SYS/KERNEL.S.IRQ.txt
2016-06-07 08:10:18 +02:00

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PR#3
PREFIX /A2OSX.SRC
NEW
INC 1
AUTO 6
.LIST OFF
*--------------------------------------
S.BrkHandlerAuxLC
bra *
*--------------------------------------
* 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
*--------------------------------------
S.IrqHandlerAuxLC
sta S.IrqMgr.A
pla
pha
and #$10 BRK?
beq .10
lda S.IrqMgr.A
.82 jmp (S.IrqMgrOldFFFE)
.10 stx S.IrqMgr.X
sty S.IrqMgr.Y
lda $fe
pha
lda $ff
pha
lda RDREADAUX
pha
sta CLRREADAUX Make sure we can access DevMgr.Table
>LDYAI DevMgr.Table
>STYA $fe
.1 lda ($fe) End Of Table ?
sec
beq .8
ldy #S.DEV.F
lda ($fe),y
and #S.DEV.F.IRQ
beq .2
jsr S.IrqHandlerJMP
bcc .8 CC, IRQ cleared by device
.2 lda $fe CS,
adc #S.DEV.SIZE-1
sta $fe
bcc .1
inc $ff
bra .1
.8 pla Must keep Carry
bpl .81
sta SETREADAUX
.81 pla
sta $ff
pla
sta $fe
ldy S.IrqMgr.Y
ldx S.IrqMgr.X
lda S.IrqMgr.A
bcs .82
rti
S.IrqHandlerJMP ldx #DEVMGR.IRQ
jmp ($fe)
*--------------------------------------
S.IrqMgrOldFFFE .BS 2
S.IrqMgr.A .BS 1
S.IrqMgr.X .BS 1
S.IrqMgr.Y .BS 1
*--------------------------------------
MAN
SAVE SYS/KERNEL.S.IRQ
LOAD SYS/KERNEL.S
ASM