mirror of
https://github.com/cc65/cc65.git
synced 2024-07-08 10:29:04 +00:00
66 lines
2.3 KiB
ArmAsm
66 lines
2.3 KiB
ArmAsm
; ---------------------------------------------------------------------------
|
|
; crt0.s
|
|
;
|
|
; for Sym-1
|
|
;
|
|
; Wayne Parham
|
|
;
|
|
; wayne@parhamdata.com
|
|
; ---------------------------------------------------------------------------
|
|
|
|
.export _init, _exit
|
|
.export __STARTUP__ : absolute = 1 ; Mark as startup
|
|
|
|
.import _main
|
|
.import initlib, donelib, copydata, zerobss
|
|
.import __RAM_START__, __RAM_SIZE__ ; Linker generated
|
|
.import __STACKSIZE__ ; Linker generated
|
|
|
|
.include "zeropage.inc"
|
|
.include "sym1.inc"
|
|
|
|
; ---------------------------------------------------------------------------
|
|
; Place the startup code in a special segment
|
|
|
|
.segment "STARTUP"
|
|
|
|
; ---------------------------------------------------------------------------
|
|
; A little light housekeeping
|
|
|
|
_init: jsr ACCESS ; Unlock System RAM
|
|
cld ; Clear decimal mode
|
|
; ---------------------------------------------------------------------------
|
|
; Turn off console echo
|
|
|
|
lda TECHO
|
|
and #$7F
|
|
sta TECHO
|
|
; ---------------------------------------------------------------------------
|
|
; Set cc65 argument stack pointer
|
|
|
|
lda #<(__RAM_START__ + __RAM_SIZE__)
|
|
sta sp
|
|
lda #>(__RAM_START__ + __RAM_SIZE__)
|
|
sta sp+1
|
|
; ---------------------------------------------------------------------------
|
|
; Initialize memory storage
|
|
|
|
jsr zerobss ; Clear BSS segment
|
|
jsr copydata ; Initialize DATA segment
|
|
jsr initlib ; Run constructors
|
|
; ---------------------------------------------------------------------------
|
|
; Call main()
|
|
|
|
jsr _main
|
|
; ---------------------------------------------------------------------------
|
|
; Back from main (this is also the _exit entry)
|
|
|
|
_exit: jsr donelib ; Run destructors
|
|
lda TECHO
|
|
ora #$80 ; Re-enable console echo
|
|
sta TECHO
|
|
jsr NACCES ; Lock System RAM
|
|
rts ; Re-enter Sym-1 monitor
|
|
; ---------------------------------------------------------------------------
|
|
|