1/*	$NetBSD: swapcontext.S,v 1.2 2003/01/18 11:15:08 thorpej Exp $	*/
2
3/*-
4 * Copyright (c) 2001 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Klaus Klein.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include "SYS.h"
33
34#if defined(LIBC_SCCS) && !defined(lint)
35	RCSID("$NetBSD: swapcontext.S,v 1.2 2003/01/18 11:15:08 thorpej Exp $")
36#endif /* LIBC_SCCS && !lint */
37
38ENTRY(swapcontext)
39	mov	%o0, %o2			! must save pointer
40	mov	%o1, %o3			! must save pointer
41	mov	SYS_getcontext, %g1
42	t	ST_SYSCALL
43	bcc,a	1f
44	 st	%g0, [%o2 + 40 + 11 * 4]	! gr[_REG_O0] = 0
45	ERROR()
461:
47	add	%o7, 12, %o1
48	st	%o1, [%o2 + 40 + 2 * 4]		! gr[_REG_nPC] = retaddr + 4
49	add	%o7, 8, %o1
50	st	%o1, [%o2 + 40 + 1 * 4]		! gr[_REG_PC] = retaddr
51
52	mov	%o3, %o0
53	mov	%o1, %g2			! optimize `return'
54	mov	SYS_setcontext|SYSCALL_G2RFLAG, %g1
55	t	ST_SYSCALL
56	ERROR()
57