nuclear@0: | vi:filetype=gas68k:
nuclear@0: 	.global start
nuclear@0: 	.global halt_cpu
nuclear@1: 	.extern main
nuclear@0: 
nuclear@1: 	.section .text.startup
nuclear@1: 
nuclear@1: 	| enter supervisor mode (assumes VBR=0)
nuclear@1: 	move.l #super, 0x80
nuclear@1: 	trap #0
nuclear@1: super:
nuclear@1: 	ori.w #0x0300, %sr	| disable interrupts
nuclear@1: 
nuclear@0: 	| zero the .bss section
nuclear@0: 	move.l #_bss_start, %a0
nuclear@0: 	move.l #_bss_end, %a1
nuclear@0: 	cmp.l %a0, %a1
nuclear@0: 	beq.s 1f	| skip zeroing if the section is empty
nuclear@0: 0:	clr.l (%a0)+
nuclear@0: 	cmp.l %a0, %a1
nuclear@0: 	bne.s 0b
nuclear@0: 1:
nuclear@0: 	| setup the stack
nuclear@0: 	move.l #_stacktop, %sp
nuclear@1: 	andi.w #0xf8ff, %sr	| enable interrupts
nuclear@0: 
nuclear@1: 	jsr main
nuclear@1: 0:	bra.b 0b
nuclear@0: 
nuclear@0: halt_cpu:
nuclear@0: 	stop #0x2700