AAAGH

Start::
	di
	ld sp, $D000
InitDone::
	call StopLCD
	ld a, $e4
	ld [rBGP], a
	xor a
	ld [rSCX], a
	ld [rSCY], a
	ld hl, Font
	ld de, _VRAM
	ld bc, FontEnd - Font
	call CopyDoubleForwards
	ld hl, Text_HelloWorld
	ld de, $9800+3+(SCRN_VY_B*7)
	ld bc, 13
	call CopyForwards
	call StartLCD
Finished::
	jr Finished

Text_HelloWorld::
	db "Hello, world!"

CopyForwards::
	;copy bc bytes forward from hl to de
	ld a, b
	or c
	ret z
	ld a, [hli]
	ld [de], a
	inc de
	dec bc
	jr CopyForwards

CopyDoubleForwards::
	;copy bc bytes forward from hl to de, twice for each byte
	ld a, b
	or c
	ret z
	ld a, [hli]
	ld [de], a
	inc de
	ld [de], a
	inc de
	dec bc
	jr CopyForwards

;	CopyBackwards::
;		;copy bc bytes backward from hl to de
;		ld a, b
;		or c
;		ret z
;		ld a, [hld]
;		ld [de], a
;		dec de
;		inc bc
;		jr CopyBackwards

StopLCD::
	ld a, [rLCDC]
	rlca
	ret nc
.wait
	ld a, [rLY]
	cp 145
	jr nz, .wait
	ld a, [rLCDC]
	res 7, a
	ld [rLCDC], a
	ret

StartLCD::
	ld a, LCDCF_ON|LCDCF_BG8000|LCDCF_BG9800|LCDCF_BGON|LCDCF_OBJ16|LCDCF_OBJOFF
	ld [rLCDC], a
	ret

Font::
	INCBIN "font.1bpp"
FontEnd::
;*** End Of File ***