4cade/src/proboothd/proboothd.s
2019-12-07 16:13:00 -08:00

148 lines
3.6 KiB
ArmAsm

;license:BSD-3-Clause
;minimal open/read binary file in ProDOS filesystem
;copyright (c) Peter Ferrie 2016-2019
!cpu 6502
!to "proboothd",plain
*=$800
;zpage usage, arbitrary selection except for the "ProDOS constant" ones
command = $42 ;ProDOS constant
unit = $43 ;ProDOS constant
adrlo = $44 ;ProDOS constant
adrhi = $45 ;ProDOS constant
bloklo = $46 ;ProDOS constant
blokhi = $47 ;ProDOS constant
A2L = $3e
A2H = $3f
sizehi = $53
;constants
scrn2p2 = $f87b
dirbuf = $1e00 ;for size-optimisation
!byte 1
tay
- txa
jsr scrn2p2
and #7
ora #$c0
sta $be30, y
sta slot+2
sta entry+2
slot lda $cfff
sta entry+1
lda fakeMLI_e-$100, y
sta $be00+fakeMLI_e-fakeMLI, y
iny
bne -
stx $bf30
sty $200
opendir ;read volume directory key block
ldx #2
;include volume directory header in count
firstent lda #>dirbuf
sta adrhi
sta A2H
jsr seekread
lda #4
sta A2L
nextent ldy #0
;match name lengths before attempting to match names
lda (A2L), y
and #$0f
tax
inx
- cmp filename, y
beq foundname
;move to next directory in this block
clc
lda A2L
adc #$27
sta A2L
bcc +
;there can be only one page crossed, so we can increment instead of adc
inc A2H
+ cmp #$ff ;4+($27*$0d)
bne nextent
;read next directory block when we reach the end of this block
ldx dirbuf+2
ldy dirbuf+3
bcs firstent
foundname iny
lda (A2L), y
dex
bne -
stx $ff
;cache KEY_POINTER
ldy #$11
lda (A2L), y
tax
iny
lda (A2L), y
tay
readfile jsr seekread
inc adrhi
inc adrhi
;fetch data block and read it
blockind ldy $ff
inc $ff
ldx dirbuf, y
lda dirbuf+256, y
tay
bne readfile
txa
bne readfile
readdone jmp $2000
seekread stx bloklo
sty blokhi
lda adrhi
pha
entry jsr $d1d1
pla
sta adrhi
rts
fakeMLI bne retcall
readblk dey
dey
sty adrhi
tay
jsr $bf00+seekread-fakeMLI
retcall pla
tax
inx
inx
inx
txa
pha
rts
fakeMLI_e
filename !byte filename_e - filename_b
filename_b !text "LAUNCHER.SYSTEM" ;your start-up file, file is max 40kb
filename_e
*=$9f8
!byte $D3,$C1,$CE,$A0,$C9,$CE,$C3,$AE