amiga_boottest
view src/startup.s @ 0:51422ea54b9d
initial commit
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Wed, 21 Feb 2018 12:00:13 +0200 |
| parents | |
| children | 48093e4bd99a |
line source
1 | vi:filetype=gas68k:
2 .text
4 .equ REG_COL0, 0xdff180
6 .global start
7 .global halt_cpu
9 start:
10 | zero the .bss section
11 move.l #_bss_start, %a0
12 move.l #_bss_end, %a1
13 cmp.l %a0, %a1
14 beq.s 1f | skip zeroing if the section is empty
15 0: clr.l (%a0)+
16 cmp.l %a0, %a1
17 bne.s 0b
18 1:
19 | setup the stack
20 move.l #_stacktop, %sp
22 | test output
23 move.w #0xf0f, REG_COL0
24 0: bra.b 0b | infloop
26 halt_cpu:
27 stop #0x2700