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https://github.com/MiSTer-devel/CDi_MiSTer.git
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d3deec71db
- Fixes bootup of Flashback - Change requires additional data from Main but is compatible with the previous Main as well.
70 lines
1.0 KiB
NASM
70 lines
1.0 KiB
NASM
section .text
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org $400000
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vector:
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dc.l $1234
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dc.l main
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main:
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; Make a pause at the start to relax the UART on the linux side
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move #4000,d0
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jsr wait
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move.l #cdicirq,$200
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move #$2000,SR
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move.w #$2480,$303FFC ; IRQ vector
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move.w #$0023,$303C00 ; Command Register = Reset Mode 1
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move.w #$8000,$303FFE ; Data buffer
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move.w #$2480,$303FFC ; Interrupt Vector
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move.w #$002c,$303C00 ; Read Mode 1
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move.l #$21080000,$303C02 ; Time Register
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move.w #$8000,$303FFE ; Start the Read
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jsr waitforirq
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move.w #$0000,$303FFE ; Data buffer = 0, disable reading
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; Send CDIC DATA1 buffer
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move.l #$300a00,a0
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move.l #$0a00,d1
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loop:
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wait_till_ready:
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move.b $80002013,d0
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btst.l #$2,d0
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beq wait_till_ready
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move.b (a0),d0
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move.b d0,$80002019
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adda.l #1,a0
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add.l #-1,d1
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bne loop
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endless:
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bra endless
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wait:
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add #-1,d0
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bne wait
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rts
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waitforirq:
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move #0,d0
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waitforirqloop:
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cmp #0,d0
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beq waitforirqloop
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rts
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cdicirq:
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move.w $303FF4,d0 ; clear flags on ABUFD
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move.w $303FF6,d0 ; clear flags on XBUF
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;move.b #$92,$80004005
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move #1,d0
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rte
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