42 lines
1.3 KiB
ArmAsm
42 lines
1.3 KiB
ArmAsm
include "../include/bplconbits.i"
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;; custom chip base globally in a6
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init:
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movem.l d0-a6,-(sp)
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move #$7ff,DMACON(a6) ; disable all dma
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move #$7fff,INTENA(a6) ; disable all interrupts
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;; set up default palette
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bsr installColorPalette
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;; set up playfield
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move.w #(RASTER_Y_START<<8)|RASTER_X_START,DIWSTRT(a6)
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move.w #((RASTER_Y_STOP-256)<<8)|(RASTER_X_STOP-256),DIWSTOP(a6)
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move.w #(RASTER_X_START/2-SCREEN_RES),DDFSTRT(a6)
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move.w #(RASTER_X_START/2-SCREEN_RES)+(8*((SCREEN_WIDTH/16)-1)),DDFSTOP(a6)
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move.w #(SCREEN_BIT_DEPTH<<12)|COLOR_ON|HOMOD,BPLCON0(a6)
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move.w #SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH-SCREEN_WIDTH_BYTES,BPL1MOD(a6)
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move.w #SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH-SCREEN_WIDTH_BYTES,BPL2MOD(a6)
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;; poke bitplane pointers
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lea bitplanes(pc),a1
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lea copper(pc),a2
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moveq #SCREEN_BIT_DEPTH-1,d0
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.bitplaneloop:
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move.l a1,d1
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move.w d1,2(a2)
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swap d1
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move.w d1,6(a2)
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lea SCREEN_WIDTH_BYTES(a1),a1 ; bit plane data is interleaved
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addq #8,a2
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dbra d0,.bitplaneloop
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;; install copper list, then enable dma and selected interrupts
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lea copper(pc),a0
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move.l a0,COP1LC(a6)
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move.w COPJMP1(a6),d0
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move.w #(DMAF_BLITTER|DMAF_SETCLR!DMAF_COPPER!DMAF_RASTER!DMAF_MASTER),DMACON(a6)
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;; move.w #(INTF_SETCLR|INTF_VERTB|INTF_INTEN),INTENA(a6)
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movem.l (sp)+,d0-a6
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rts |