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cc65/libsrc/atmos/crt0.s
cuz 756091e31f Must import sp now that the zp definitions are elsewhere
git-svn-id: svn://svn.cc65.org/cc65/trunk@1612 b7a2c559-68d2-44c3-8de9-860c34a00d81
2002-11-23 22:06:01 +00:00

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1.4 KiB
ArmAsm

;
; Startup code for cc65 (Oric version)
;
; By Debrune Jérôme <jede@oric.org> and Ullrich von Bassewitz <uz@cc65.org>
;
; This must be the *first* file on the linker command line
;
.export _exit
.import initlib, donelib
.import push0, _main, zerobss
.import __RAM_START__, __RAM_SIZE__ ; Linker generated
.importzp sp
; ------------------------------------------------------------------------
; Create an empty LOWCODE segment to avoid linker warnings
.segment "LOWCODE"
; ------------------------------------------------------------------------
; Place the startup code in a special segment.
.segment "STARTUP"
; Clear the BSS data
jsr zerobss
; Save system stuff and setup the stack
tsx
stx spsave ; save system stk ptr
lda #<(__RAM_START__ + __RAM_SIZE__)
sta sp
lda #>(__RAM_START__ + __RAM_SIZE__)
sta sp+1 ; Set argument stack ptr
; Call module constructors
jsr initlib
; Pass an empty command line
jsr push0 ; argc
jsr push0 ; argv
ldy #4 ; Argument size
jsr _main ; call the users code
; Call module destructors. This is also the _exit entry.
_exit: jsr donelib ; Run module destructors
; Restore system stuff
ldx spsave
txs
; Back to BASIC
rts
; ------------------------------------------------------------------------
; Data
.bss
spsave: .res 1