- SECTION "a",HOME
+ section "end",HOME[1024]
+ nop
+
+ SECTION "a",HOME[$00]
+
+start: jp main
+
+ section "vbl",HOME[$40]
+ jp vbl
+
+ section "lcdc",HOME[$48]
+ jp lcdc
+
+ section "tmro",HOME[$50]
+ jp tmro
main:
- ld c, $51 ; Note that we are alive.
ld a, $FF
- ld [c],a
-
+ ld c, $51
+ ld [c], a
+
ld sp, $DFF0
- ld c, $07
ld a, $04 ;start timer, 4.096KHz
+ ld c, $07
ld [c], a
-
+
ld hl, $DF81
xor a
ld [hli], a
signon:
db $0D,$0A,$1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0
- section "fuq",HOME[$100]
-irqhand:
+vbl:
PUSH AF
PUSH BC
PUSH DE
PUSH HL
xor a
- ld c, $0F ; ack the irq
+ ld c, $0F
+ ld [c], a
+
+ ld c, $42 ; SCY
+ ld a, [c]
+ inc a
+ ld [c], a
+
+ POP HL
+ POP DE
+ POP BC
+ POP AF
+
+ RETI
+
+lcdc:
+ PUSH AF
+ PUSH BC
+
+ xor a
+ ld c, $0F
+ ld [c], a
+
+ POP BC
+ POP AF
+
+ reti
+
+tmro:
+ PUSH AF
+ PUSH BC
+ PUSH DE
+ PUSH HL
+
+ xor a
+ ld c, $0F
+ ld [c], a
+
+ ld c, $45 ; LYC
+ ld a, [c]
+ inc a
ld [c], a
ld hl, $DF82
ld a, $41 ; print A
call putc
.noprint:
+ inc [hl]
ld a, [hl]
- add 1
ld c, $51
ld [c], a
- ld [hl], a
POP HL
POP DE
cpl
cp $AA
jr nz,.fail
+
+ ; Test DI/EI delay
+ di
+ ld hl, .dinocausefail
+ ld c, $0F ; First, wait until an interrupt happens...
+.wait: ld a, [c]
+ and $04
+ cp 0
+ jr z, .wait
+ ei ; Now make sure that an IRQ didn't happen on EI/DI
+ di
+ ld a, [c]
+ and $04
+ cp 0
+ jr z, .fail
+ ld hl, .dicausefail
+ ei ; Make sure that an IRQ does happen on EI/NOP/DI
+ nop
+ nop
+ di
+ ld a, [c]
+ and $04
+ cp 0
+ jr nz, .fail
+ ei
ld hl, .ok
call puts
ret
.fail:
+ ei
call puts
ld hl, .testfailed
call puts
db "CPL",0
.inc16fail:
db "INC16",0
+.dinocausefail:
+ db "DI/EI does not cause interrupt",0
+.dicausefail:
+ db "DI/NOP/EI cause interrupt",0
.testfailed:
db " test failed.",$0D,$0A,0
.ok:
ret z
call putc
jr puts
+