.text
.globl main
+.globl INT
.globl VBL
##################################################
.equ VDP1_E_DMA, 0x10
.equ VDP1_NTSC, 0x00
.equ VDP1_PAL, 0x08
-.equ VDP1_RESERVED, 0x04
+.equ VDP1_MODE5, 0x04
.equ VDP12_STE, 0x08
.equ VDP12_SCREEN_V224, 0x00
.equ MMODE_GOTO, 3
.equ MMODE_START_MENU, 4
.equ MMODE_GOTO_PREDEF, 5
+.equ MMODE_JMP_ADDR, 6
.equ predef_addr_cnt, ((predef_addrs_end-predef_addrs)/4)
write_vdp_r_dst \reg, \val, (a3)
.endm
-/* For immediate addresses */
-.macro VRAM_ADDR reg adr
- move.l #(((0x4000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
-.endm
-
-.macro CRAM_ADDR reg adr
- move.l #(((0xc000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
+# Set up address in VDP, control port in dst
+.macro VRAM_ADDR adr dst
+ move.l #(((0x4000 | (\adr & 0x3fff)) << 16) | (\adr >> 14)),\dst
.endm
.endm
-.macro VSCROLL_ADDR reg adr
- move.l #(((0x4000 + (\adr & 0x3fff)) << 16) + ((\adr >> 14) | 0x10)),\reg
-.endm
-
-
-.macro HSCROLL_ADDR reg adr
- move.l #(((0x4000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
-.endm
-
-
# convert tile coords in d0, d1 to nametable addr to a0
.macro XY2NT
lsl.w #6,d1
dc.w 0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
dc.w 0x0000,0x0e44,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
dc.w 0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
+ dc.w 0x0000,0x044e,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
+ dc.w 0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
colors_end:
predef_addrs:
dc.l 0x000000, 0x200000, 0x400000, 0xa00000, 0xa10000
- dc.l 0xa11100, 0xa12000, 0xa13000, 0xc00000
+ dc.l 0xa11100, 0xa12000, 0xa13000, 0xa14000, 0xc00000
predef_addrs_end:
safe_addrs:
dc.l 0x000000, 0x7fffff
dc.l 0xe00000, 0xffffff
- dc.l 0xa00000, 0xa163ff /* FIXME */
- /* TODO: VDP */
+ dc.l 0xa00000, 0xa100ff
+ dc.l 0xa11000, 0xa113ff
+ dc.l 0xa12000, 0xa120ff
+ dc.l 0xa13000, 0xa130ff
safe_addrs_end:
txt_edit:
.ascii "Go to address\0"
txt_goto_predef:
.ascii "Go to (predef)\0"
+txt_jmp_addr:
+ .ascii "Jump to address\0"
txt_dtack:
.ascii "DTACK safety\0"
+txt_dtack_err:
+ .ascii "DTACK err?\0"
+txt_exc:
+ .ascii "Exception \0"
##################################################
# #
moveq.l #(colors_end-colors)/2,d0
jsr load_colors
- /* load patterns */
- movea.l #0,a0
- movea.l #font,a1
- move.l #128,d0
- jsr load_tiles
+ /* load font patterns */
+ lea GFXDATA,a0
+ lea font,a1
+ VRAM_ADDR 0,(GFXCNTL)
+ move.w #128*8,d3
+font_loop:
+ moveq.l #8-1,d2
+ moveq.l #0,d1
+ move.b (a1)+,d0
+0:
+ lsr.b #1,d0
+ roxl.l #1,d1
+ ror.l #5,d1
+ dbra d2,0b
+
+ rol.l #1,d1 /* fixup */
+ move.l d1,(a0)
+ dbra d3,font_loop
/* generate A layer map */
movea.l #0xe000,a1
0: move.l (a1)+,(a0)
dbra d3,0b
+ /* wait for vsync before unmask */
+ move.l #GFXCNTL,a3
+0:
+ move.w (a3),d0
+ and.b #8,d0
+ nop
+ nop
+ beq 0b
+
move.w #0x2000,sr
##################################################
bra forever
+INT:
+ /* let's hope VRAM is already set up.. */
+ lea txt_exc,a0
+ move.l #9,d0
+ move.l #27,d1
+ move.l #0xe000,d2
+ jsr print
+ bra forever
+
+##################################################
+
VBL:
addq.b #1,d7
- movem.l d0-d4/a0-a5,-(a7)
+# movem.l d0-d4/a0-a5,-(a7)
moveq.l #0,d0
move.w d7,d0
dc.l mode_goto
dc.l mode_start_menu
dc.l mode_goto_predef
- dc.l mode_main
+ dc.l mode_jmp_addr
dc.l mode_main
##################### main #######################
mode_main:
- clr.l d1
+ /* assume we will hang */
+ lea txt_dtack_err,a0
+ move.l #9,d0
+ move.l #27,d1
+ move.l #0xe000,d2
+ jsr print
+
+ moveq.l #0,d1
move.l a6,d0
move.b d0,d1
lsr.l #8,d0
btst.l #4,d6
bne draw_row_safe
- bsr is_addr_safe
- bne draw_row_safe
+ bsr get_safety_mask
+ cmp.b #0xf,d0
+ beq draw_row_safe
-# draw unreadable areas
+# unsafe or partially safe
+draw_row_hsafe:
+ move.l d0,d4
+ swap d4 /* mask in upper word */
btst.l #15,d7
- bne draw_row_unsafe_words
+ bne draw_row_hsafe_words_pre
-draw_row_unsafe_bytes:
+draw_row_hsafe_bytes_pre:
/* 8 bytes */
- moveq.l #8-1,d4
-0:
+ moveq.l #2,d3
+ move.w #3,d4
+
+draw_row_hsafe_bytes:
+ move.w #' ',(a0)
+ move.b d4,d0
+ add.b #16,d0
+ btst.l d0,d4
+ bne 0f
+ move.l #'?'|('?'<<16),(a0)
move.w #' ',(a0)
move.l #'?'|('?'<<16),(a0)
- dbra d4,0b
+ bra 1f
+0:
+ move.b (0,a1),d2
+ jsr print_hex_preped
+ move.w #' ',(a0)
+ move.b (1,a1),d2
+ jsr print_hex_preped
+1:
+ addq.l #2,a1
+ dbra d4,draw_row_hsafe_bytes
move.w #' ',(a0)
swap d0
cmp.w d5,d0
beq draw_cursor_unsafe_byte
- bra draw_chars_unsafe
+ bra draw_chars_hsafe_pre
-draw_row_unsafe_words:
+draw_row_hsafe_words_pre:
/* 4 shorts */
- moveq.l #4-1,d4
-0:
+ moveq.l #4,d3
+ move.w #3,d4
+
+draw_row_hsafe_words:
move.w #' ',(a0)
+ move.b d4,d0
+ add.b #16,d0
+ btst.l d0,d4
+ bne 0f
move.l #'?'|('?'<<16),(a0)
move.l #'?'|('?'<<16),(a0)
- dbra d4,0b
+ bra 1f
+0:
+ move.w (a1),d2
+ jsr print_hex_preped
+1:
+ addq.l #2,a1
+ dbra d4,draw_row_hsafe_words
move.l #(' '<<16)|' ',(a0)
cmp.w d5,d0
beq draw_cursor_unsafe_word
-draw_chars_unsafe:
- move.l #'?'|('?'<<16),(a0)
- move.l #'?'|('?'<<16),(a0)
- move.l #'?'|('?'<<16),(a0)
+draw_chars_hsafe_pre:
+ subq.l #8,a1
+ move.w #3,d4
+ moveq.l #0,d0
+
+draw_chars_hsafe:
+ move.b d4,d0
+ add.b #16,d0
+ btst.l d0,d4
+ bne 0f
move.l #'?'|('?'<<16),(a0)
+ bra draw_chars_hsafe_next
+0:
+ btst.l #15,d7 /* must perform correct read type */
+ bne 0f /* doing byte reads on security reg hangs */
+ move.b (0,a1),d0
+ lsl.l #8,d0
+ move.b (1,a1),d0
+ bra 1f
+0:
+ move.w (a1),d0
+1:
+ ror.l #8,d0
+ move.b d0,d1
+ sub.b #0x20,d1
+ cmp.b #0x60,d1
+ blo 0f
+ move.b #'.',d0
+0:
+ move.w d0,(a0)
+
+ move.b #0,d0
+ rol.l #8,d0
+ move.b d0,d1
+ sub.b #0x20,d1
+ cmp.b #0x60,d1
+ blo 0f
+ move.b #'.',d0
+0:
+ move.w d0,(a0)
+
+draw_chars_hsafe_next:
+ addq.l #2,a1
+ dbra d4,draw_chars_hsafe
move.l #(' '<<16)|' ',(a0)
- addq.l #8,a1
add.w #0x80,a2
dbra d5,draw_row
bra draw_status_bar
add.w #0x80,a2
dbra d5,draw_row
+
draw_status_bar:
/* status bar */
move.l a2,a0
mk_a6_addr d2
move.l #0x4006,d3
jsr print_hex_preped
- move.w #' ',(a0)
+
+ /* clear error */
+ moveq.l #5-1,d0
+0:
+ move.l #' '|(' '<<16),(a0)
+ move.l #' '|(' '<<16),(a0)
+ dbra d0,0b
+
/* handle input */
jsr get_input /* x0cbrldu x1sa00du */
input_nos:
vbl_end:
- movem.l (a7)+,d0-d4/a0-a5
+# movem.l (a7)+,d0-d4/a0-a5
rte
move.l a2,a0
add.w #31*2,a0
jsr load_prepare /* restore a0 */
- jmp draw_chars_unsafe
+ jmp draw_chars_hsafe_pre
draw_cursor_unsafe_word:
move.l a6,d0
move.l a2,a0
add.w #29*2,a0
jsr load_prepare /* restore a0 */
- jmp draw_chars_unsafe
+ jmp draw_chars_hsafe_pre
draw_cursor_byte:
menu_text txt_about, 13, 9, 1
menu_text txt_goto, 13, 11, 0
menu_text txt_goto_predef, 13, 12, 0
- menu_text txt_dtack, 13, 13, 0
- menu_text txt_a_confirm, 13, 15, 2
+ menu_text txt_jmp_addr, 13, 13, 0
+ menu_text txt_dtack, 13, 14, 0
+ menu_text txt_a_confirm, 13, 16, 2
/* dtack safety on/off */
- movea.l #0xe000+26*2+13*64*2,a0
+ movea.l #0xe000+26*2+14*64*2,a0
jsr load_prepare
move.w #0x8000|'O',(a0)
btst.l #4,d6
add.b d2,d1
cmp.b #0,d1
bge 0f
- move.b #2,d1
+ move.b #3,d1
0:
- cmp.b #2,d1
+ cmp.b #3,d1
ble 0f
move.b #0,d1
0:
0:
cmp.b #2,d1
bne 0f
+ change_mode MMODE_JMP_ADDR, MMODE_MAIN
+ bsr start_menu_box
+ jmp vbl_end
+0:
+ cmp.b #3,d1
+ bne 0f
bchg.l #4,d6
jmp vbl_end
0:
start_menu_box:
movea.l #0xe000+10*2+8*64*2,a1
- move.w #9-1,d1
+ move.w #10-1,d1
0:
move.w a1,a0
jsr load_prepare
mgp_no_bc:
jmp vbl_end
+##################### jmp ########################
+
+mode_jmp_addr:
+ btst.l #7,d6
+ bne mode_jmp_finish
+
+ moveq.l #0,d5
+ or.b #3,d5 /* 3 bytes */
+ bclr.l #7,d6
+ change_mode MMODE_VAL_INPUT, MMODE_JMP_ADDR
+ jmp vbl_end
+
+mode_jmp_finish:
+ lsr.l #8,d5
+ write_vdp_r_dst 1,(VDP1_E_DISPLAY | VDP1_MODE5),(GFXCNTL) /* disable vint */
+ move.l d5,a0
+ jmp (a0)
+
# go back to main mode
return_to_main:
init_gfx:
move.l #GFXCNTL,a3
write_vdp_reg 0,(VDP0_E_DISPLAY | VDP0_PLTT_FULL)
- write_vdp_reg 1,(VDP1_E_VBI | VDP1_E_DISPLAY | VDP1_E_DMA | VDP1_RESERVED)
+ write_vdp_reg 1,(VDP1_E_VBI | VDP1_E_DISPLAY | VDP1_MODE5)
write_vdp_reg 2,(0xe000 >> 10) /* Screen map a adress */
write_vdp_reg 3,(0xe000 >> 10) /* Window address */
write_vdp_reg 4,(0xc000 >> 13) /* Screen map b address */
rts
-# determine if address packed in a6 is safe
+# get mask of bits representing safe words
# a1 - address to check
# destroys d0-d2, strips upper bits from a1
-is_addr_safe:
+get_safety_mask:
move.l a1,d1
lsl.l #8,d1
lsr.l #8,d1
addq.l #4,a1
dbra d2,0b
-addr_unsafe:
move.l d1,a1
- moveq.l #0,d0
+
+ moveq.l #0x0c,d0
+ cmp.l #0xa14000,d1
+ beq gsm_rts
+
+ moveq.l #0x08,d0
+ cmp.l #0xa14100,d1
+ beq gsm_rts
+
+ /* check for VDP address */
+ move.l d1,d0
+ swap d0
+ and.b #0xe0,d0
+ cmp.b #0xc0,d0
+ bne addr_unsafe /* not vdp */
+
+ move.l d1,d0
+ and.l #0x0700e0,d0
+ bne addr_unsafe
+
+ move.l d1,d0
+ and.b #0x1f,d0
+ cmp.b #0x04,d0
+ blt addr_hsafe_3 /* data port */
+ cmp.b #0x10,d0
+ blt addr_safe /* below PSG */
+ cmp.b #0x18,d0
+ bge addr_safe /* above PSG */
+
+addr_unsafe:
+ moveq.l #0,d0 /* skip line */
+ rts
+
+addr_hsafe_3:
+ moveq.l #3,d0 /* skip 2 words */
rts
addr_safe:
move.l d1,a1
- moveq.l #1,d0
+ moveq.l #0xf,d0
+gsm_rts:
rts
move.w d1,d0
rts
-# Load tile data from ROM
-# a0: VRAM base
-# a1: pattern address
-# d0: number of tiles to load
-# destroys d1
-
-load_tiles:
- move.l d0,d1
- VRAM_ADDR_var a0
- move.l d0,(GFXCNTL).l
-
- 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 @a0
# sets a0 to VDP data port for convenience
# a0: VRAM base
rts
-#################################################
-# #
-# Wait for next VBlank interrupt #
-# #
-#################################################
+# wait vertical sync
wait_vsync:
move.b d7,d0
notaz.gp2x.de / megadrive.git / blobdiff