xref: /netbsd-src/sys/arch/sgimips/stand/common/iris_start.S (revision d02e022db788ed4933c5904d9d6ce3af08f11fee)
1/*	$NetBSD: iris_start.S,v 1.1 2019/01/12 16:44:47 tsutsui Exp $	*/
2
3/*
4 * Copyright (c) 2018 Naruaki Etomi
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28/*
29 * Silicon Graphics "IRIS" series MIPS processors machine bootloader.
30 */
31
32#include <mips/asm.h>
33#include <mips/cpuregs.h>
34
35	.globl	start
36start:
37	.set	noreorder
38#ifdef __GP_SUPPORT__
39	la	gp, _C_LABEL(_gp)
40#endif
41	/*
42	 * We assume the bootprom isn't expecting us to preserve the saved
43	 * registers.
44	 */
45	move	s0, a0				# save argc
46	move	s1, a1				# save argv
47	move	s2, a2				# save envp
48	move	s3, ra				# save RA
49
50	la	a0, _C_LABEL(edata)		# clear BSS
51	move	a1, zero
52	la	a2, _C_LABEL(end)
53	jal	_C_LABEL(memset)		# memset(edata, 0, end - edata)
54	 subu	a2, a2, a0
55
56	move	a0, s0				# restore argc
57	move	a1, s1				# restore argv
58	move	a2, s2				# restore envp
59	j	_C_LABEL(main)			# main(argc, argv)
60	 move	ra, s3				# restore RA
61
62LEAF(romrestart)
63XLEAF(_rtt)
64	PTR_LA	v0, 0xBFC00000			# indigo RESET
65	j	v0
66	 nop
67END(romrestart)
68