New target c16

git-svn-id: svn://svn.cc65.org/cc65/trunk@1563 b7a2c559-68d2-44c3-8de9-860c34a00d81
2002-11-21 21:22:26 +00:00
parent c80596458c
commit e41c0adbb2
25 changed files with 808 additions and 7 deletions
--- a/libsrc/c16/crt0.s
+++ b/libsrc/c16/crt0.s
@@ -0,0 +1,109 @@
+;
+; Startup code for cc65 (C16 version)
+;
+; This must be the *first* file on the linker command line
+;                            
+; Note: The C16 is actually the Plus/4 with just 16KB of memory. So many
+; things are similar here, and we even use the plus4.inc include file.
+;
+
+	.export		_exit
+	.import		initlib, donelib
+	.import	     	push0, _main, zerobss
+        .import         MEMTOP, RESTOR, BSOUT, CLRCH
+
+        .include        "zeropage.inc"
+	.include	"../plus4/plus4.inc"
+
+
+; ------------------------------------------------------------------------
+; BASIC header with a SYS call
+
+.code
+
+	.org	$0FFF
+        .word   Head            ; Load address
+Head:   .word   @Next
+        .word   1000            ; Line number
+        .byte   $9E,"4109"	; SYS 4109
+        .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
+	jsr	BSOUT
+
+; Clear the BSS data
+
+	jsr	zerobss
+
+; Save system stuff and setup the stack
+
+       	tsx
+       	stx    	spsave       	; save system stk ptr
+
+	sec
+	jsr	MEMTOP		; Get top memory
+	cpy	#$80  		; We can only use the low 32K :-(
+	bcc	MemOk
+	ldy	#$80
+	ldx	#$00
+MemOk:	stx	sp
+      	sty	sp+1  		; set argument stack ptr
+
+; Call module constructors
+
+	jsr	initlib
+
+; 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
+
+; Copy back the zero page stuff
+
+	ldx	#zpspace-1
+L2:	lda	zpsave,x
+	sta	sp,x
+	dex
+       	bpl	L2
+
+; Reset changed vectors
+
+	jmp	RESTOR
+
+
+.data
+zpsave:	.res	zpspace
+
+.bss
+spsave:	.res	1
+
+