Joshua Wise's Git repositories - fpgaboy.git/blame_incremental

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Commit	Line	Data
	1	SECTION "a",HOME
	2
	3	main:
	4	ld c, $51 ; Note that we are alive.
	5	ld a, $FF
	6	ld [c],a
	7
	8	ld sp, $DFFF
	9
	10	ld hl, signon
	11	call puts
	12
	13	call memtest
	14
	15	call insntest
	16
	17	call waitsw
	18
	19	jp main
	20
	21	signon:
	22	db $0D,$0A,$1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0
	23
	24	; Memory tester: writes h ^ l to all addresses from C000 to DF80.
	25	memtest:
	26	ld hl,memteststr
	27	call puts
	28
	29	ld hl, $C000 ; Write loop
	30	.wr:
	31	ld a,h
	32	xor l
	33	ld [hli],a
	34	ld a, $DF
	35	cp h
	36	jp nz, .wr
	37	ld a, $80
	38	cp l
	39	jp nz, .wr
	40
	41	ld hl, $C000 ; Read loop
	42	.rd:
	43	ld a,h
	44	xor l
	45	ld b,a
	46	ld a, [hli]
	47	cp b
	48	jp nz, .memfail
	49
	50	ld a, $DF
	51	cp h
	52	jp nz, .rd
	53	ld a, $80
	54	cp l
	55	jp nz, .rd
	56
	57	ld hl, testokstr ; Say we're OK
	58	call puts
	59	ret
	60	.memfail: ; Say we failed (sadface)
	61	; decrement hl the easy way
	62	ld a,[hld]
	63	push hl
	64	ld hl, failatstr
	65	call puts
	66	pop hl
	67	ld a, h
	68	call puthex
	69	ld a, l
	70	call puthex
	71	ld a, $0A
	72	call putc
	73	ld a, $0D
	74	call putc
	75	ret
	76	memteststr:
	77	db "Testing memory from $C000 to $DF80...",0
	78	testokstr:
	79	db " OK!",$0D,$0A,0
	80	failatstr:
	81	db " Test failed at $",0
	82
	83	puthex: ; Put two hex nibbles to the serial console.
	84	push af
	85	rra
	86	rra
	87	rra
	88	rra
	89	ld b,$0F
	90	and b
	91	ld b,$30
	92	add b
	93	call putc
	94	pop af
	95	ld b,$0F
	96	and b
	97	ld b,$30
	98	add b
	99	call putc
	100	ret
	101
	102	; Wait for switches to be flipped on and off again.
	103	waitsw:
	104	ld hl,waitswstr
	105	call puts
	106
	107	ld c, $51
	108	ld a, $00
	109	ld [c],a
	110
	111	ld c, $51
	112	ld b, $0
	113	.loop1:
	114	ld a,[c]
	115	cp b
	116	jp z,.loop1
	117	.loop2:
	118	ld a,[c]
	119	cp b
	120	jp nz,.loop2
	121	ret
	122
	123	waitswstr:
	124	db "Diagnostic ROM complete; flip switches to nonzero and then to zero to reset.",$0D,$0A,0
	125
	126	; Core instruction basic acceptance tests.
	127	insntest:
	128	ld hl, .insnteststr
	129	call puts
	130
	131	; Test PUSH and POP.
	132	ld b, $12
	133	ld c, $34
	134	ld d, $56
	135	ld e, $78
	136	push bc
	137	pop de
	138	ld hl, .pushpopfail
	139	ld a, d
	140	cp b
	141	jp nz,.fail
	142	ld a, e
	143	cp c
	144	jp nz,.fail
	145
	146	; Test ALU (HL).
	147	ld hl, .ff
	148	ld a, $FF
	149	xor [hl]
	150	ld hl, .xorhlfail
	151	jp nz, .fail
	152
	153	; Test CP.
	154	ld hl, .cpfail
	155	ld a, $10
	156	ld b, $20
	157	cp b
	158	jp nc,.fail
	159	ld a, $20
	160	ld b, $10
	161	cp b
	162	jp c,.fail
	163
	164	; Test CPL
	165	ld hl, .cplfail
	166	ld a, $55
	167	ld b, $AA
	168	cpl
	169	cp b
	170	jp nz,.fail
	171
	172	ld hl, .ok
	173	call puts
	174	ret
	175	.fail:
	176	call puts
	177	ret
	178	.insnteststr:
	179	db "Testing instructions... ",$0
	180	.pushpopfail:
	181	db "PUSH/POP test failed.",$0D,$0A,0
	182	.ff:
	183	db $FF
	184	.xorhlfail:
	185	db "XOR [HL] test failed.",$0D,$0A,0
	186	.cpfail:
	187	db "CP test failed.",$0D,$0A,0
	188	.cplfail:
	189	db "CPL test failed.",$0D,$0A,0
	190	.ok:
	191	db "OK!",$0D,$0A,0
	192
	193	; Serial port manipulation functions.
	194	putc:
	195	push af
	196	ld b, 0
	197	ld c, $50
	198	.waitport:
	199	ld a,[c]
	200	cp b
	201	jp nz,.waitport
	202	pop af
	203	ld [c],a
	204	ret
	205
	206	puts:
	207	ld a, [hli]
	208	ld b, $00
	209	cp b
	210	jp z, .done
	211	call putc
	212	jp puts
	213	.done:
	214	ret
	215