1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/startup.s	Wed Feb 21 12:00:13 2018 +0200
     1.3 @@ -0,0 +1,27 @@
     1.4 +| vi:filetype=gas68k:
     1.5 +	.text
     1.6 +
     1.7 +	.equ REG_COL0, 0xdff180
     1.8 +
     1.9 +	.global start
    1.10 +	.global halt_cpu
    1.11 +
    1.12 +start:
    1.13 +	| zero the .bss section
    1.14 +	move.l #_bss_start, %a0
    1.15 +	move.l #_bss_end, %a1
    1.16 +	cmp.l %a0, %a1
    1.17 +	beq.s 1f	| skip zeroing if the section is empty
    1.18 +0:	clr.l (%a0)+
    1.19 +	cmp.l %a0, %a1
    1.20 +	bne.s 0b
    1.21 +1:
    1.22 +	| setup the stack
    1.23 +	move.l #_stacktop, %sp
    1.24 +
    1.25 +	| test output
    1.26 +	move.w #0xf0f, REG_COL0
    1.27 +0:	bra.b 0b	| infloop
    1.28 +
    1.29 +halt_cpu:
    1.30 +	stop #0x2700