[fpgaboy.git] / rom.asm

	SECTION "a",HOME
main:
	ld c, $51
	ld a, $FF
	ld [c],a
	ld sp,$DFFF

	ld hl,text
	call puts
	
	call memtest
	call waitsw
	jp main

text:
	db $1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0

memtest:
	ld hl,memteststr
	call puts
	
	ld hl, $C000
.wr:
	ld a,h
	xor l
	ld [hli],a
	ld a, $DF
	cp h
	jp nz, .wr
	ld a, $80
	cp l
	jp nz, .wr

	ld hl, $C000
.rd:
	ld a,h
	xor l
	ld b,a
	ld a, [hli]
	cp b
	jp nz, .memfail
	
	ld a, $DF
	cp h
	jp nz, .rd
	ld a, $80
	cp l
	jp nz, .rd
	
	ld hl, testokstr
	call puts
	ret
.memfail:
	@ decrement hl the easy way
	ld a,[hld]
	push hl
	ld hl, failatstr
	call puts
	pop hl
	ld a, h
	call puthex
	ld a, l
	call puthex
	ld a, $0A
	call putc
	ld a, $0D
	call putc
	ret

memteststr:
	db "Testing memory from $C000 to $DF80...",0
testokstr:
	db " OK!",$0D,$0A,0
failatstr:
	db " Test failed at $",0
puthex:
	push af
	rra
	rra
	rra
	rra
	ld b,$0F
	and b
	ld b,$30
	add b
	call putc
	pop af
	ld b,$0F
	and b
	ld b,$30
	add b
	call putc
	ret

waitsw:
	ld hl,waitswstr
	call puts
	
	ld c, $51
	ld a, $00
	ld [c],a
	
	ld c, $51
	ld b, $0
.loop1:
	ld a,[c]
	cp b
	jp z,.loop1
.loop2:
	ld a,[c]
	cp b
	jp nz,.loop2
	ret

waitswstr:
	db "Diagnostic ROM complete; flip switches to nonzero and then to zero to reset.",$0D,$0A,0

putc:
	push af
	ld b, 0
	ld c, $50
.waitport:
	ld a,[c]
	cp b
	jp nz,.waitport
	pop af
	ld [c],a
	ret

puts:
	ld a, [hli]
	ld b, $00
	cp b
	jp z, .done
	call putc
	jp puts
.done:
	ret
Commit	Line	Data
616eebe0 JW	1	SECTION "a",HOME
	2	main:
	3	ld c, $51
	4	ld a, $FF
	5	ld [c],a
	6	ld sp,$DFFF
	7
	8	ld hl,text
	9	call puts
	10
	11	call memtest
	12	call waitsw
	13	jp main
	14
	15	text:
	16	db $1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0
	17
	18	memtest:
	19	ld hl,memteststr
	20	call puts
	21
	22	ld hl, $C000
	23	.wr:
	24	ld a,h
	25	xor l
	26	ld [hli],a
	27	ld a, $DF
	28	cp h
	29	jp nz, .wr
	30	ld a, $80
	31	cp l
	32	jp nz, .wr
	33
	34	ld hl, $C000
	35	.rd:
	36	ld a,h
	37	xor l
	38	ld b,a
	39	ld a, [hli]
	40	cp b
	41	jp nz, .memfail
	42
	43	ld a, $DF
	44	cp h
	45	jp nz, .rd
	46	ld a, $80
	47	cp l
	48	jp nz, .rd
	49
	50	ld hl, testokstr
	51	call puts
	52	ret
	53	.memfail:
	54	@ decrement hl the easy way
	55	ld a,[hld]
	56	push hl
	57	ld hl, failatstr
	58	call puts
	59	pop hl
	60	ld a, h
	61	call puthex
	62	ld a, l
	63	call puthex
	64	ld a, $0A
65	call putc
66	ld a, $0D
67	call putc
68	ret
69
70	memteststr:
71	db "Testing memory from $C000 to $DF80...",0
72	testokstr:
73	db " OK!",$0D,$0A,0
74	failatstr:
75	db " Test failed at $",0
76	puthex:
77	push af
78	rra
79	rra
80	rra
81	rra
82	ld b,$0F
83	and b
84	ld b,$30
85	add b
86	call putc
87	pop af
88	ld b,$0F
89	and b
90	ld b,$30
91	add b
92	call putc
93	ret
94
95	waitsw:
96	ld hl,waitswstr
97	call puts
98
99	ld c, $51
100	ld a, $00
101	ld [c],a
102
103	ld c, $51
104	ld b, $0
105	.loop1:
106	ld a,[c]
107	cp b
108	jp z,.loop1
109	.loop2:
110	ld a,[c]
111	cp b
112	jp nz,.loop2
113	ret
114
115	waitswstr:
116	db "Diagnostic ROM complete; flip switches to nonzero and then to zero to reset.",$0D,$0A,0
117
118	putc:
119	push af
120	ld b, 0
121	ld c, $50
122	.waitport:
123	ld a,[c]
124	cp b
125	jp nz,.waitport
126	pop af
127	ld [c],a
128	ret
129
130	puts:
131	ld a, [hli]
132	ld b, $00
133	cp b
134	jp z, .done
135	call putc
136	jp puts
137	.done:
138	ret
139