xref: /netbsd-src/lib/libc/arch/arm/gen/swapcontext.S (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1/*	$NetBSD: swapcontext.S,v 1.4 2004/08/21 11:20:10 rearnsha 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 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *        This product includes software developed by the NetBSD
21 *        Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 *    contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39#include "SYS.h"
40
41#if defined(LIBC_SCCS) && !defined(lint)
42        RCSID("$NetBSD: swapcontext.S,v 1.4 2004/08/21 11:20:10 rearnsha Exp $")
43#endif /* LIBC_SCCS && !lint */
44
45ENTRY(swapcontext)
46	stmfd	sp!, {r0-r1, lr}	/* Must save oucp, ucp, lr. */
47	bl	PIC_SYM(_C_LABEL(_getcontext), PLT)  /* getcontext(oucp) */
48	cmp	r0, #0
49	ldmfd	sp!, {r0-r1, lr}
50	RETc(ne)
51	str	lr, [r0, #(36 + 15*4)]	/* Adjust saved PC. */
52#ifdef SOFTFLOAT
53	/* Ahem. */
54#endif
55	mov	r0, r1
56	bl	PIC_SYM(_C_LABEL(setcontext), PLT)
57	RET
58