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cc65/libsrc/atari5200/crt0.s
2014-04-25 03:02:44 +02:00

49 lines
1.1 KiB
ArmAsm

;
; Startup code for cc65 (Atari5200 version)
;
; Christian Groessler (chris@groessler.org), 2014
;
.export _exit, start
.export __STARTUP__ : absolute = 1 ; Mark as startup
.import __RAM_START__, __RAM_SIZE__
.import __RESERVED_MEMORY__
.import initlib, donelib, callmain
.import zerobss, copydata
.include "zeropage.inc"
.include "atari5200.inc"
start:
; Clear the BSS data
jsr zerobss
; initialize data
jsr copydata
; setup the stack
lda #<(__RAM_START__ + __RAM_SIZE__ - __RESERVED_MEMORY__)
sta sp
lda #>(__RAM_START__ + __RAM_SIZE__ - __RESERVED_MEMORY__)
sta sp+1 ; Set argument stack ptr
; Call module constructors
jsr initlib
; Push arguments and call main()
jsr callmain
; Call module destructors. This is also the _exit entry.
_exit: jsr donelib ; Run module destructors
; A 5200 program isn't supposed to exit.
halt: jmp halt