; ; Startup code for cc65 (Apple2 version) ; ; This must be the *first* file on the linker command line ; .export _exit .import initlib, donelib .import zerobss .import __STARTUP_LOAD__, __BSS_LOAD__ ; Linker generated .import callmain .include "zeropage.inc" .include "apple2.inc" ; ------------------------------------------------------------------------ ; The executable header .segment "EXEHDR" .word __STARTUP_LOAD__ ; Start address .word __BSS_LOAD__ - __STARTUP_LOAD__ ; Size ; ------------------------------------------------------------------------ ; Place the startup code in a special segment. .segment "STARTUP" ; ProDOS TechRefMan, chapter 5.2.1: ; "For maximum interrupt efficiency, a system program should not use more ; than the upper 3/4 of the stack." ldx #$FF txs ; Init stack pointer ; Save the zero page locations we need ldx #zpspace-1 L1: lda sp,x sta zpsave,x dex bpl L1 ; Clear the BSS data jsr zerobss ; Save system stuff and setup the stack lda HIMEM sta sp lda HIMEM+1 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 ; Copy back the zero page stuff ldx #zpspace-1 L2: lda zpsave,x sta sp,x dex bpl L2 ; ProDOS TechRefMan, chapter 5.2.1: ; "System programs should set the stack pointer to $FF at the warm-start ; entry point." ldx #$FF txs ; Re-init stack pointer ; Back to DOS jmp DOSWARM ; ------------------------------------------------------------------------ ; Data .data zpsave: .res zpspace