xref: /netbsd-src/lib/libc/arch/powerpc/gen/swapcontext.S (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
1/*	$NetBSD: swapcontext.S,v 1.3 2003/10/03 22:37:35 kleink 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	.text
43	.asciz "$NetBSD: swapcontext.S,v 1.3 2003/10/03 22:37:35 kleink Exp $"
44#endif /* LIBC_SCCS && !lint */
45
46ENTRY(swapcontext)
47	stwu	%r1,-16(%r1)			# set up new stack frame
48	mflr	%r0
49	stw	%r0,20(%r1)			# save link register
50	stw	%r3,8(%r1)			# must save oucp
51	stw	%r4,12(%r1)			# must save ucp
52	bl	PIC_PLT(_C_LABEL(_getcontext))	# getcontext(oucp)
53	cmpwi	%r3,0
54	bne	1f
55	lwz	%r11,8(%r1)			# load oucp for adjustment
56	lwz	%r0,20(%r1)
57	stw	%r0,(48 + 34 * 4)(%r11)		# pc <- lr
58	la	%r0,16(%r1)
59	stw	%r0,(48 +  1 * 4)(%r11)		# adjust sp
60	lwz	%r3,12(%r1)			# load ucp
61	bl	PIC_PLT(_C_LABEL(setcontext))	# setcontext(ucp)
621:
63	lwz	%r0,20(%r1)
64	mtlr	%r0
65	la	%r1,16(%r1)
66	blr
67