.text
.globl main
+.globl VBL
##################################################
# #
.endm
-# make VDP word from address adr to d0
-# destroys d7
-.macro VRAM_ADDR_var adr
+.macro CRAM_ADDR reg adr
+ move.l #(((0xc000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
+.endm
+
+
+# make VDP word from address adr and store in d0
+.macro XRAM_ADDR_var adr
move.l \adr,d0
- move.l \adr,d7
- and.w #0x3fff,d0
- lsr.w #7,d7
- lsr.w #7,d7
- add.w #0x4000,d0
- lsl.l #7,d0
- lsl.l #7,d0
- lsl.l #2,d0
- or.l d7,d0
+ lsl.l #8,d0
+ lsl.l #8,d0
+ rol.l #2,d0
+ lsl.b #2,d0
+ lsr.l #2,d0
.endm
-.macro CRAM_ADDR reg adr
- move.l #(((0xc000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
+.macro VRAM_ADDR_var adr
+ XRAM_ADDR_var \adr
+ or.l #0x40000000,d0
.endm
-/* For indirect (variable) addresses */
-.macro CRAM_ADDR_var reg adr
- move.l \adr,d6
- move.l \adr,d7
- and.w #0x3fff,d6
- lsr.w #7,d7
- lsr.w #7,d7
- add.w #0xc000,d6
- lsl.l #7,d6
- lsl.l #7,d6
- lsl.l #2,d6
- or.l d7,d6
- move.l d6,\reg
+.macro CRAM_ADDR_var adr
+ XRAM_ADDR_var \adr
+ or.l #0xc0000000,d0
.endm
.endm
+# convert tile coords in d0, d1 to nametable addr to a0
+.macro XY2NT
+ lsl.w #6,d1
+ add.w d1,d0
+ lsl.w #1,d0
+ movea.l #0xe000,a0
+ add.w d0,a0
+.endm
+
#################################################
# #
# DATA #
.align 2
main:
+ /* mask irqs durinf init */
+ move.w #0x2700,sr
+
+ movea.l #0,a6
+
+ /* Init pads */
+ move.b #0x40,(0xa10009).l
+ move.b #0x40,(0xa10003).l
+
/* Initialize VDP */
jsr init_gfx
/* Load color data */
- movea.l #0,a3
- movea.l #colors,a4
- moveq.l #(colors_end-colors)/2,d4
+ movea.l #0,a0
+ movea.l #colors,a1
+ moveq.l #(colors_end-colors)/2,d0
jsr load_colors
/* load patterns */
- movea.l #0,a3
- movea.l #font,a4
- move.l #128,d4
+ movea.l #0,a0
+ movea.l #font,a1
+ move.l #128,d0
jsr load_tiles
/* generate A layer map */
- movea.l #0xe000,a6
+ movea.l #0xe000,a1
move.l #28-1,d4
lmaploop0:
- movea.l a6,a3
+ movea.l a1,a0
jsr load_prepare
move.l #64/2-1,d3
-0: move.l #0x00000000,(a3)
+0: move.l #0x00000000,(a0)
dbra d3,0b
- add.l #64*2,a6
+ add.l #64*2,a1
dbra d4,lmaploop0
/* generate B layer map */
- movea.l #0xc000,a3
+ movea.l #0xc000,a0
jsr load_prepare
move.l #64*28/2-1,d3
-0: move.l #0x00000000,(a3)
+0: move.l #0x00000000,(a0)
dbra d3,0b
/* upload sprite data */
- movea.l #0xfc00,a3
+ movea.l #0xfc00,a0
jsr load_prepare
- movea.l #sprite_data,a0
+ movea.l #sprite_data,a1
move.l #(sprite_data_end-sprite_data)/2-1,d3
-0: move.l (a0)+,(a3)
+0: move.l (a1)+,(a0)
dbra d3,0b
- jsr wait_vsync
-
- movea.l #hello,a0
- moveq.l #1,d0
- moveq.l #1,d1
- jsr print
+ move.w #0x2000,sr
##################################################
# #
# #
##################################################
+# global regs:
+# a6 - page[31:8],cursor_offs[7:0]
+
forever:
+VBL:
+ addq.l #1,(vtimer).l
+ movem.l d0-d7/a0-a5,-(a7)
+
+ /* draw main stuff */
+ clr.l d7
+ move.l a6,d0
+ lsr.l #8,d0
+ move.l d0,a1 /* current addr */
+
+ movea.l #0xe004,a2
+ move.l #27-1,d5
+
+draw_column:
+ move.l a2,a0
+ jsr load_prepare
+
+ /* addr */
+ move.l a1,d2
+ moveq.l #6,d3
+ jsr print_hex_preped
+
+ /* 4 shorts */
+ moveq.l #4-1,d4
+draw_shorts:
+ move.w #' ',(a0)
+ move.w (a1)+,d2
+ moveq.l #4,d3
+ jsr print_hex_preped
+ dbra d4,draw_shorts
+
+ move.w #' ',(a0)
+ move.w #' ',(a0)
+
+ /* 8 chars */
+ subq.l #8,a1
+ moveq.l #8-1,d4
+draw_chars:
+ move.b (a1)+,d0
+ move.b d0,d1
+ sub.b #0x20,d1
+ cmp.b #0x60,d1
+ blo 0f
+ move.w #'.',d0
+0:
+ move.w d0,(a0)
+ dbra d4,draw_chars
+
+ add.w #0x80,a2
+ dbra d5,draw_column
+
+ /* handle input */
+ jsr get_input /* x0cbrldu x1sa00du */
+ btst.b #0,d0
+ beq _in_nup
+ sub.l #0x0800,a6
+
+_in_nup:
+ btst.b #1,d0
+ beq _in_ndn
+ add.l #0x0800,a6
+
+_in_ndn:
+ btst.l #10,d0
+ beq _in_nleft
+ sub.l #0xd800,a6
+
+_in_nleft:
+ btst.b #11,d0
+ beq _in_nright
+ add.l #0xd800,a6
+
+_in_nright:
+
+end:
+ movem.l (a7)+,d0-d7/a0-a5
+ rte
+
+
#################################################
# #
# Initialize VDP registers #
rts
+# read single phase from controller
+# a0 - addr
+# d0 - result
+get_input:
+ move.b #0x40,(0xa10003)
+ nop
+ nop
+ nop
+ move.b (0xa10003),d0
+ move.b #0x00,(0xa10003)
+ lsl.w #8,d0
+ nop
+ move.b (0xa10003),d0
+ eor.w #0xffff,d0
+# move.b #0x40,(0xa10003)
+ rts
-#################################################
-# #
-# Load tile data from ROM #
-# #
-# Parameters: #
-# a3: VRAM base #
-# a4: pattern address #
-# d4: number of tiles to load #
-# Destroys a2,d0,d7... #
-# #
-#################################################
+# Load tile data from ROM
+# a0: VRAM base
+# a1: pattern address
+# d0: number of tiles to load
+# destroys d1
load_tiles:
- move.l #GFXCNTL,a2
- VRAM_ADDR_var a3
- move.l d0,(a2)
- lsl #3,d4
+ move.l d0,d1
+ VRAM_ADDR_var a0
+ move.l d0,(GFXCNTL).l
- move.l #GFXDATA,a3
- subq.l #1,d4
-_copy_tile_data:
- move.l (a4)+,(a3)
- dbra d4,_copy_tile_data
+ move.l #GFXDATA,a0
+ lsl.w #3,d1
+ subq.l #1,d1
+0:
+ move.l (a1)+,(a0)
+ dbra d1,0b
rts
# Prepare to write to VDP RAM @a3
-# a3: VRAM base
-# a3 set to VDP data port for convenience
-# destroys a2,d0,d7
+# sets a0 to VDP data port for convenience
+# a0: VRAM base
+# destroys d0
load_prepare:
- move.l #GFXCNTL,a2
- VRAM_ADDR_var a3
- move.l d0,(a2)
- move.l #GFXDATA,a3
-
+ VRAM_ADDR_var a0
+ move.l d0,(GFXCNTL).l
+ move.l #GFXDATA,a0
rts
-#################################################
-# #
-# Load color data from ROM #
-# #
-# Parameters: #
-# a3: CRAM base #
-# a4: color list address #
-# d4: number of colors to load #
-# #
-#################################################
+# Load color data from ROM
+# a0: CRAM base
+# a1: color list address
+# d0: number of colors to load
+# destroys d1
load_colors:
- move.l #GFXCNTL,a2
- CRAM_ADDR_var d0,a3
- move.l d0,(a2)
+ move.l d0,d1
+ CRAM_ADDR_var a0
+ move.l d0,(GFXCNTL).l
- move.l #GFXDATA,a3
- subq.w #1,d4
-_copy_color_data:
- move.w (a4)+,(a3)
- dbra d4,_copy_color_data
+ move.l #GFXDATA,a0
+ subq.w #1,d1
+0:
+ move.w (a1)+,(a0)
+ dbra d1,0b
rts
-#################################################
-##
-## print
-# a0 - string
-# d0 - x
-# d1 - y
+
+# print
+# a0 - string
+# d0 - x
+# d1 - y
+# destroys a1
print:
- lsl.w #6,d1
- add.w d1,d0
- movea.l #0xe000,a6
- lsl.w #1,d0
- add.w d0,a6
- moveq.l #0,d1
+ move.l a0,a1
+ XY2NT
+ jsr load_prepare
+ moveq.l #0,d0
_print_loop:
- move.b (a0)+,d1
+ move.b (a1)+,d0
beq _print_end
- move.l a6,a3
- jsr load_prepare
- move.w d1,(a3)
- addq.l #2,a6
+ move.w d0,(a0)
jmp _print_loop
_print_end:
rts
+# print_hex
+# d0 - x
+# d1 - y
+# d2 - value
+# d3 - digit cnt
+# destroys a0
+
+print_hex:
+ XY2NT
+ jsr load_prepare
+
+print_hex_preped:
+ move.l d3,d0
+ lsl.b #2,d0
+ ror.l d0,d2 /* prep value */
+ moveq.l #0,d0
+ subq.l #1,d3 /* count */
+
+_print_hex_loop:
+ rol.l #4,d2
+ move.b d2,d0
+ and.b #0xf,d0
+ cmp.b #0xa,d0
+ bge 1f
+
+ add.b #'0',d0
+ jmp 2f
+1:
+ add.b #0x37,d0
+2:
+ move.w d0,(a0)
+ dbra d3,_print_hex_loop
+
+ rts
+
+
#################################################
# #
# Wait for next VBlank interrupt #
notaz.gp2x.de / megadrive.git / blobdiff