; ; Startup code for cc65 (PET version) ; ; This must be the *first* file on the linker command line ; .export _exit .import initlib, donelib .import initconio, zerobss, push0 .import _main .include "pet.inc" .include "../cbm/cbm.inc" ; ------------------------------------------------------------------------ ; Define and export the ZP variables for the C64 runtime .exportzp sp, sreg, regsave .exportzp ptr1, ptr2, ptr3, ptr4 .exportzp tmp1, tmp2, tmp3, tmp4 .exportzp regbank, zpspace .zeropage zpstart = * sp: .res 2 ; Stack pointer sreg: .res 2 ; Secondary register/high 16 bit for longs regsave: .res 2 ; slot to save/restore (E)AX into ptr1: .res 2 ptr2: .res 2 ptr3: .res 2 ptr4: .res 2 tmp1: .res 1 tmp2: .res 1 tmp3: .res 1 tmp4: .res 1 regbank: .res 6 ; 6 byte register bank zpspace = * - zpstart ; Zero page space allocated .code ; ------------------------------------------------------------------------ ; BASIC header with a SYS call .org $3FF .word Head ; Load address Head: .word @Next .word 1000 ; Line number .byte $9E,"1037" ; SYS 1037 .byte $00 ; End of BASIC line @Next: .word 0 ; BASIC end marker .reloc ; ------------------------------------------------------------------------ ; Actual code ldx #zpspace-1 L1: lda sp,x sta zpsave,x ; Save the zero page locations we need dex bpl L1 ; Close open files jsr CLRCH ; Switch to second charset lda #14 ; sta $E84C ; See PET FAQ jsr BSOUT ; Clear the BSS data jsr zerobss ; Save system stuff and setup 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 module constructors jsr initlib ; Initialize conio stuff jsr initconio ; 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 ; Restore stack pointer ; Copy back the zero page stuff ldx #zpspace-1 L2: lda zpsave,x sta sp,x dex bpl L2 ; Back to basic rts .data zpsave: .res zpspace .bss spsave: .res 1 mmusave:.res 1