;
; Startup code for cc65 (PET version)
-;
-; This must be the *first* file on the linker command line
;
- .export _exit
- .import initlib, donelib
- .import zerobss, push0
- .import callmain
+ .export _exit
+ .export __STARTUP__ : absolute = 1 ; Mark as startup
+ .import initlib, donelib
+ .import zerobss, push0
+ .import callmain
.import CLRCH, BSOUT
+ .importzp ST
.include "zeropage.inc"
- .include "pet.inc"
- .include "../cbm/cbm.inc"
+ .include "pet.inc"
+ .include "../cbm/cbm.inc"
; ------------------------------------------------------------------------
-; Place the startup code in a special segment.
-
-.segment "STARTUP"
+; Startup code
-; BASIC header with a SYS call
+.segment "STARTUP"
- .word Head ; Load address
-Head: .word @Next
- .word .version ; Line number
- .byte $9E,"1037" ; SYS 1037
- .byte $00 ; End of BASIC line
-@Next: .word 0 ; BASIC end marker
-
-; ------------------------------------------------------------------------
-; Actual code
+Start:
- ldx #zpspace-1
-L1: lda sp,x
- sta zpsave,x ; Save the zero page locations we need
- dex
- bpl L1
+; Save the zero-page locations that we need.
-; Close open files
+ ldx #zpspace-1
+L1: lda sp,x
+ sta zpsave,x
+ dex
+ bpl L1
- jsr CLRCH
+; Switch to the second charset. The routine that is called by BSOUT to switch the
+; character set will use FNLEN as temporary storage -- YUCK! Since the
+; initmainargs routine, which parses the command line for arguments, needs that
+; information, we need to save and restore it here.
+; Thanks to Stefan Haubenthal for this information!
-; Switch to second charset
+ lda FNLEN
+ pha ; Save FNLEN
+ lda #14
+; sta $E84C ; See PET FAQ
+ jsr BSOUT
+ pla
+ sta FNLEN ; Restore FNLEN
- lda #14
-; sta $E84C ; See PET FAQ
- jsr BSOUT
+; Clear the BSS data.
-; Clear the BSS data
+ jsr zerobss
- jsr zerobss
+; Save some system stuff; and, set up the stack.
-; Save system stuff and setup the stack
+ tsx
+ stx spsave ; Save the system stack ptr
- tsx
- stx spsave ; Save the system stack ptr
+ lda MEMSIZE
+ sta sp
+ lda MEMSIZE+1
+ sta sp+1 ; Set argument stack ptr
- lda MEMSIZE
- sta sp
- lda MEMSIZE+1
- sta sp+1 ; Set argument stack ptr
+; Call the module constructors.
-; Call module constructors
+ jsr initlib
- jsr initlib
+; Push the command-line arguments; and, call main().
-; Push arguments and call main()
+ jsr callmain
- jsr callmain
+; Call the module destructors. This is also the exit() entry.
-; Call module destructors. This is also the _exit entry.
+_exit: pha ; Save the return code on stack
+ jsr donelib
-_exit: jsr donelib ; Run module destructors
+; Copy back the zero-page stuff.
-; Restore system stuff
+ ldx #zpspace-1
+L2: lda zpsave,x
+ sta sp,x
+ dex
+ bpl L2
- ldx spsave
- txs ; Restore stack pointer
+; Store the program return code into BASIC's status variable.
-; Copy back the zero page stuff
+ pla
+ sta ST
- ldx #zpspace-1
-L2: lda zpsave,x
- sta sp,x
- dex
- bpl L2
+; Restore the stack pointer.
-; Back to basic
+ ldx spsave
+ txs ; Restore stack pointer
- rts
+; Back to BASIC.
+ rts
; ------------------------------------------------------------------------
-; Data
-.data
+.segment "ZPSAVE"
-zpsave: .res zpspace
+zpsave: .res zpspace
-.bss
+; ------------------------------------------------------------------------
-spsave: .res 1
-mmusave:.res 1
+.bss
+spsave: .res 1
+mmusave:.res 1