_lwp.c revision 1.2 
1/*	$NetBSD: _lwp.c,v 1.2 2003/01/18 11:06:25 thorpej Exp $	*/
2
3/*
4 * Copyright (c) 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 *    must display the following acknowledgement:
19 *	This product includes software developed for the NetBSD Project by
20 *	Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 *    or promote products derived from this software without specific prior
23 *    written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38#include <sys/types.h>
39#include <ucontext.h>
40#include <lwp.h>
41#include <stdlib.h>
42
43void
44_lwp_makecontext(ucontext_t *u, void (*start)(void *),
45    void *arg, void *private, caddr_t stack_base, size_t stack_size)
46{
47	void **sp;
48
49	getcontext(u);
50	u->uc_link = NULL;
51
52	u->uc_stack.ss_sp = stack_base;
53	u->uc_stack.ss_size = stack_size;
54
55	sp = (void **) (stack_base + stack_size);
56
57	/*
58	 * Note: We make sure the stack is 8-byte aligned, here.
59	 */
60
61	u->uc_mcontext.__gregs[_REG_R0] = (__greg_t) arg;
62	u->uc_mcontext.__gregs[_REG_SP] = ((__greg_t) sp) & ~7;
63	u->uc_mcontext.__gregs[_REG_LR] = (__greg_t) _lwp_exit;
64	u->uc_mcontext.__gregs[_REG_PC] = (__greg_t) start;
65}
66