.text
.globl main
+.globl INT
.globl VBL
##################################################
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 (predef)\0"
txt_dtack:
.ascii "DTACK safety\0"
+txt_dtack_err:
+ .ascii "DTACK err?\0"
+txt_exc:
+ .ascii "Exception \0"
##################################################
# #
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)
##################### 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)
- dbra d4,0b
+ move.w #' ',(a0)
+ move.l #'?'|('?'<<16),(a0)
+ 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 */
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:
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
notaz.gp2x.de / megadrive.git / blobdiff