1
0
mirror of https://github.com/pfusik/xasm.git synced 2024-12-22 15:31:23 +00:00
xasm/xbootpro.asx
2013-01-07 12:07:27 +01:00

70 lines
948 B
Plaintext

* Boot executable file loader coded by Fox/Taquart
* Version for professionals - can load file under ROM.
* Note interrupts and ROM are disabled when running loaded program.
opt h-
org $480
bufr equ $400
tp equ $43
vc equ $44
* Boot header
boot equ *
rts rts
dta b(1),a(boot,$e477)
* Nice blank screen
mva #0 $22f
mva #$52 $2c8
lda 20
cmp 20
beq *-2
* Init run vector
mwa #rts $2e0
ldy #$fe
* Load header
lhead mwa #rts $2e2
ldx <-5
* Store byte of header
hput sta vc+4,x+
stx tp
jmp get
next inw vc
get iny
bpl getx
inw $30a
mva #$ff ^31
lsr ^4e
cli
jsr $e453
sec
bmi rts
sei
mvy #0 ^4e
dec ^31
getx lda bufr,y
ldx tp
bne hput
sta (vc,x)
lda vc
cmp vc+2
bne next
lda vc+1
cmp vc+3
bne next
endseq tya
pha
jsr init
pla
tay
bpl lhead !
init jmp ($2e2)
* This will be added at the end of loaded file
opt h+
org endseq
jmp ($2e0)
end