include 'hfs.aii'

boot	proc

	stz offset
	lda #2
	jsr read_block


	endp

read_block proc
	; input
	; a = hfs block #
	; will be adjusted for allocation block offset
	; 
	clc
	adc offset
	sta block
	phx
	phy

	ply
	plx
	rts
	endp

findit	proc
;
; assumes 512-byte blocks (max size = ....?)
;
; wait a minute... max 65535 blocks, therefore high word of allocation block, etc, always 0.
;

;
; search for a file named ! in the root directory.
; ! is ascii char $21 so it should sort early.
;
;
	lda header+drAlBlSt
	xba
	sta offset

	lda header+drCTExtRec ; 1st allocation block
	xba
	sta cat_extents
	lda header+drCTExtRec+2 ; # of allocation blocks
	xba
	sta cat_extents+2
	;
	; need to do all 3?
	;

;	lda offset
;	clc
;	adc cat_extents
	lda cat_extents
	jsr read_block

	;
	; block should be a btree header block. find the first leaf node.
	;
	lda block+$18
	xba
	sta leaf+2
	lda block+$18+2
	xba
	sta leaf
	;
	; assert leaf < # allocated lbocks?
	;
	;lda leaf
	jsr read_block

	lda block+$a ; # of records
	xba
;	asl a ; x 2
;	sec
;	sbc #512
;	eor #-1
;	inc a
;	adc #-513 ; carry will be clear. +1 to avoid inc
;	eor #-1
	sta count
	beq advance

again
	ldx #512-2 ; last entry 
@loop
	lda block,x
	tay
	lda block+2,y ; parent id
	bne notfound
	lda block+4,y
	xba
	cmp #2
	blt @next
	beq @name
	bge notfound
@name	; name is a p-string.
	lda block+6+1,y
	and #$ff
	cmp #'!'
	blt @next
	beq @name2
	bge notfound
@name2	lda block+6,y
	cmp #$2101
	bne notfound
	brl found
@next	dex
	dex
	dec count
	bne @loop
advance ; next block!
	lda block+2
	beq notfound
	xba
	jsr read_block
	bra again

notfound
	brk $ea

found
	; y = offset in block
	;
	; only works with contiguous files....
	; first block?

	; assume < 65535 bytes :)
	lda block+filPyLen+2,y
;	xba
	lsr a ; >>9 since already xba
	and #%01111111
	beq notfound
	sta count
	lda block+filExtRec,y
	xba
	sta extent
	lda block+filExtRec+2,y
	xba
	sta extent+2

	; now load the blocks and
	lda #$2000
	sta dest
	lda extent
	clc
	adc offset
	sta block
@loop
	jsr read_block2
	inc block
	lda #512
	clc
	adc dest
	sta dest
	dec count
	bne @loop

	jmp $2000 ; kiss of life.


	endp




	end