Add nintendo logo to diag. Add xmodem loader. Add auxboot and binwire utilities.
[fpgaboy.git] / xm.asm
CommitLineData
2bcaaabf
JW
1 SECTION "wee",HOME[$0]
2 ; this all needs to be PIC!
3st:
4 ld sp, $CFFF
5 xor a
6 ld hl, $FF60
7 ld [hli], a
8 ld [hli], a
9 ld [hli], a
10nak:
11 ld a, $15 ; NAK
12 call putc+$FF80
13
14.ack: call getc+$FF80
15 cp $01 ;SOH
16 jr z,.soh
17 cp $04 ;EOT
18 jr z, .eot
19 cp $18 ;CAN
20 jr z, .rst
21 jr .donak
22
23.eot:
24 ld A, $06 ; Ack the EOT
25 call putc+$FF80
26.rst: rst $00
27
28.soh: call getc+$FF80 ; blk
29 call getc+$FF80 ; iblk
30 xor a
31 ld b, a
32 ld l, a
33 ld h, $C0
34.lp: call getc+$FF80
35 ld [hli], a
36 add b
37 ld b, a
38 bit 7, l
39 jr z, .lp
40.cksm: call getc+$FF80
41 cp b
42 jr nz, .donak
43 ld hl, $C000
44.lp2: jr z, .doack
45 ld a, [hli]
46 ld [$FF63], A
47 bit 7, l
48 jr z,.lp2
49.doack: ld A, $06
50 call putc+$FF80
51 jr .ack
52.donak: call getc+$FF80 ; Wait until the line clears, and then once
53 jr .donak ; that happens, getc will cause a NAK.
54
55getc:
56 xor d
57 xor e
58.dgetc:
59 dec de
60 xor a
61 cp d
62 jr z, .timeout
63 ld a, [$FF53]
64 and $02
65 jr z, .dgetc
66 ld a, [$FF52]
67 ret
68.timeout:
69 ld hl, $D000
70 ld a, [hl]
71 inc a
72 ld [hl], a
73 ld [$FF51], a
74 jr nak
75
76putc:
77 ld c, $53
78 push af
79.waitport:
80 ld a,[c]
81 and $01
82 jr nz,.waitport
83 pop af
84 ld [$FF52],a
85 ret
86
87 section "a", HOME[$7F]
88 nop
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