_lwp.c revision 1.2 
1/*	$NetBSD: _lwp.c,v 1.2 2003/01/18 11:04:40 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 Nathan J. Williams.
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/types.h>
40#include <ucontext.h>
41#include <lwp.h>
42#include <stdlib.h>
43
44void
45_lwp_makecontext(ucontext_t *u, void (*start)(void *),
46    void *arg, void *private, caddr_t stack_base, size_t stack_size)
47{
48	__greg_t *gr;
49
50	getcontext(u);
51	gr = u->uc_mcontext.__gregs;
52
53	u->uc_link = NULL;
54
55	u->uc_stack.ss_sp = stack_base;
56	u->uc_stack.ss_size = stack_size;
57
58	gr[_REG_PC] = (unsigned long)start;
59	gr[_REG_T12] = (unsigned long) start;
60	gr[_REG_RA] = (unsigned long) _lwp_exit;
61	gr[_REG_A0] = (unsigned long) arg;
62	gr[_REG_SP] = ((unsigned long) (stack_base + stack_size)) & ~0x7;
63	gr[_REG_S6] = 0;
64}
65