[fpgaboy.git] / fpgaboot.asm

	SECTION "boot", HOME[$0]
boot:	ld a, $AA
	ld [$FF51], A	; Poke the LEDs

	ld sp, $FFFE
	
	ld hl, signon
	call puts
	
.wait:	ld a, [$FF53]
	and $02
	jr z, .nodata
	ld a, [$FF52]
	ld [$FF51], a
	
	cp $1B		; Escape
	jp z, .cbc
	ld [$FF52], a
.cbc:	call z, bootcmd

.nodata:	ld a, [$FF51]
	cp $00
	jr nz, .wait

doboot:	xor a
	ld h, a
	ld l, a
	ld [hl], $01	; Select the GB boot rom
	
	ld a, $55
	ld [c], a
	
	ld hl, booting
	call puts
	
	rst $00		; Boot

signon:
	db $0D,$0A,$1B,"[1mFPGABoy Boot ROM",$1B,"[0m",$0D,$0A,0
booting:
	db "Booting...",$0D,$0A,0

putc:
	ld c, $53
	push af
.waitport:
	ld a,[c]
	and $01
	jr nz,.waitport
	pop af
	ld [$FF52],a
	ret

puts:
	ld a, [hli]
	cp $00
	ret z
	call putc
	jr puts

getc:
	ld a, [$FF53]
	and $02
	jr z, getc
	ld a, [$FF52]
	ret

bootcmd:
	call getc
	cp $56	;V
	jr z,.version
	cp $41	;A
	jr z,.addr
	cp $44	;D
	jr z,.data
	cp $50	;P
	jr z,.prog
	cp $42	;B
	jr z,doboot
	cp $1B
	jr z,bootcmd	; If you keep yelling, you're bound to get the thing's attention.
	ld a, $3f	;?
	jr putc
.version:
	ld hl, .verstr
	jr puts
.verstr:
	db "V1.00",0
.addr:
	call getc
	ld [$FF60], A
	call getc
	ld [$FF61], A
	call getc
	ld [$FF62], A
	ld A, $41	;A
	jr putc
.data:
	call getc	; byte count
	ld c, a
.dl:	call getc
	ld [$FF63], A
	dec c
	jp nz, .dl
	ld A, $44	;D
	ret
.prog:
	ld hl, $FF80
	ld c, $7F
.pl:	dec c
	jp z, $FF80
	call getc
	ld [hli], a
	jr .pl
	
	SECTION "a", HOME[$100]
	nop	; Make sure we don't overflow.
Commit	Line	Data
49c326da	1	SECTION "boot", HOME[$0]
1eefdc8e	2	boot: ld a, $AA
49c326da	3	ld [$FF51], A ; Poke the LEDs
1eefdc8e JW	4
	5	ld sp, $FFFE
	6
	7	ld hl, signon
	8	call puts
49c326da	9
298e8085 JW	10	.wait: ld a, [$FF53]
	11	and $02
	12	jr z, .nodata
	13	ld a, [$FF52]
	14	ld [$FF51], a
49c326da	15
298e8085 JW	16	cp $1B ; Escape
	17	jp z, .cbc
	18	ld [$FF52], a
	19	.cbc: call z, bootcmd
	20
	21	.nodata: ld a, [$FF51]
1eefdc8e JW	22	cp $00
	23	jr nz, .wait
	24
298e8085	25	doboot: xor a
1eefdc8e JW	26	ld h, a
	27	ld l, a
	28	ld [hl], $01 ; Select the GB boot rom
	29
	30	ld a, $55
	31	ld [c], a
	32
	33	ld hl, booting
	34	call puts
	35
	36	rst $00 ; Boot
	37
298e8085 JW	38	signon:
	39	db $0D,$0A,$1B,"[1mFPGABoy Boot ROM",$1B,"[0m",$0D,$0A,0
	40	booting:
	41	db "Booting...",$0D,$0A,0
	42
1eefdc8e JW	43	putc:
	44	ld c, $53
	45	push af
	46	.waitport:
	47	ld a,[c]
298e8085	48	and $01
1eefdc8e JW	49	jr nz,.waitport
	50	pop af
	51	ld [$FF52],a
	52	ret
	53
	54	puts:
	55	ld a, [hli]
	56	cp $00
	57	ret z
	58	call putc
	59	jr puts
	60
298e8085 JW	61	getc:
	62	ld a, [$FF53]
	63	and $02
	64	jr z, getc
	65	ld a, [$FF52]
	66	ret
1eefdc8e	67
298e8085 JW	68	bootcmd:
	69	call getc
	70	cp $56 ;V
	71	jr z,.version
	72	cp $41 ;A
	73	jr z,.addr
	74	cp $44 ;D
	75	jr z,.data
	76	cp $50 ;P
	77	jr z,.prog
	78	cp $42 ;B
	79	jr z,doboot
	80	cp $1B
	81	jr z,bootcmd ; If you keep yelling, you're bound to get the thing's attention.
	82	ld a, $3f ;?
	83	jr putc
	84	.version:
	85	ld hl, .verstr
	86	jr puts
	87	.verstr:
	88	db "V1.00",0
	89	.addr:
	90	call getc
	91	ld [$FF60], A
	92	call getc
	93	ld [$FF61], A
	94	call getc
	95	ld [$FF62], A
	96	ld A, $41 ;A
	97	jr putc
	98	.data:
	99	call getc ; byte count
	100	ld c, a
	101	.dl: call getc
	102	ld [$FF63], A
	103	dec c
	104	jp nz, .dl
	105	ld A, $44 ;D
	106	ret
	107	.prog:
	108	ld hl, $FF80
	109	ld c, $7F
	110	.pl: dec c
	111	jp z, $FF80
	112	call getc
	113	ld [hli], a
	114	jr .pl
	115
49c326da JW	116	SECTION "a", HOME[$100]
	117	nop ; Make sure we don't overflow.
	118