mirror of
https://github.com/cc65/cc65.git
synced 2024-12-23 19:29:37 +00:00
106 lines
2.4 KiB
ArmAsm
106 lines
2.4 KiB
ArmAsm
;
|
|
; Startup code for cc65 (PET version)
|
|
;
|
|
|
|
.export _exit
|
|
.export __STARTUP__ : absolute = 1 ; Mark as startup
|
|
.import initlib, donelib
|
|
.import zerobss, push0
|
|
.import callmain
|
|
.import CLRCH, BSOUT
|
|
.importzp ST
|
|
|
|
.include "zeropage.inc"
|
|
.include "pet.inc"
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Startup code
|
|
|
|
.segment "STARTUP"
|
|
|
|
Start:
|
|
|
|
; Save the zero-page locations that we need.
|
|
|
|
ldx #zpspace-1
|
|
L1: lda sp,x
|
|
sta zpsave,x
|
|
dex
|
|
bpl L1
|
|
|
|
; Switch to the second charset. The routine that is called by BSOUT to switch the
|
|
; character set will use FNLEN as temporary storage -- YUCK! Since the
|
|
; initmainargs routine, which parses the command line for arguments, needs that
|
|
; information, we need to save and restore it here.
|
|
; Thanks to Stefan Haubenthal for this information!
|
|
|
|
lda FNLEN
|
|
pha ; Save FNLEN
|
|
lda #14
|
|
; sta $E84C ; See PET FAQ
|
|
jsr BSOUT
|
|
pla
|
|
sta FNLEN ; Restore FNLEN
|
|
|
|
; Clear the BSS data.
|
|
|
|
jsr zerobss
|
|
|
|
; Save some system stuff; and, set up the stack.
|
|
|
|
tsx
|
|
stx spsave ; Save the system stack ptr
|
|
|
|
lda MEMSIZE
|
|
sta sp
|
|
lda MEMSIZE+1
|
|
sta sp+1 ; Set argument stack ptr
|
|
|
|
; Call the module constructors.
|
|
|
|
jsr initlib
|
|
|
|
; Push the command-line arguments; and, call main().
|
|
|
|
jsr callmain
|
|
|
|
; Call the module destructors. This is also the exit() entry.
|
|
|
|
_exit: pha ; Save the return code on stack
|
|
jsr donelib
|
|
|
|
; Copy back the zero-page stuff.
|
|
|
|
ldx #zpspace-1
|
|
L2: lda zpsave,x
|
|
sta sp,x
|
|
dex
|
|
bpl L2
|
|
|
|
; Store the program return code into BASIC's status variable.
|
|
|
|
pla
|
|
sta ST
|
|
|
|
; Restore the stack pointer.
|
|
|
|
ldx spsave
|
|
txs ; Restore stack pointer
|
|
|
|
; Back to BASIC.
|
|
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
|
|
.segment "INIT"
|
|
|
|
zpsave: .res zpspace
|
|
|
|
; ------------------------------------------------------------------------
|
|
|
|
.bss
|
|
|
|
spsave: .res 1
|
|
mmusave:.res 1
|