xref: /netbsd-src/lib/libc/arch/arm/gen/swapcontext.S (revision 7788a0781fe6ff2cce37368b4578a7ade0850cb1)
1/*	$NetBSD: swapcontext.S,v 1.9 2012/11/28 02:18:24 matt 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#include "assym.h"
34
35#if defined(LIBC_SCCS) && !defined(lint)
36        RCSID("$NetBSD: swapcontext.S,v 1.9 2012/11/28 02:18:24 matt Exp $")
37#endif /* LIBC_SCCS && !lint */
38
39ENTRY(swapcontext)
40	stmfd	sp!, {r0-r1, lr}	/* Must save oucp, ucp, lr. */
41	sub	sp, sp, #4
42	bl	PIC_SYM(_C_LABEL(_getcontext), PLT)  /* getcontext(oucp) */
43	cmp	r0, #0
44	add	sp, sp, #4
45	ldmfd	sp!, {r0-r1, lr}
46	RETc(ne)
47	str	sp, [r0, #_UC_REGS_SP]	/* Adjust saved SP. */
48	str	lr, [r0, #_UC_REGS_PC]	/* Adjust saved PC. */
49#ifdef SOFTFLOAT
50	/* Ahem. */
51#endif
52	mov	r0, r1
53	bl	PIC_SYM(_C_LABEL(setcontext), PLT)
54	RET
55