1 /* $NetBSD: _lwp.c,v 1.1 2014/09/03 19:34:25 matt Exp $ */
2
3 /*
4 * Copyright (c) 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Allen Briggs 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/cdefs.h>
39 #if defined(LIBC_SCCS) && !defined(lint)
40 __RCSID("$NetBSD: _lwp.c,v 1.1 2014/09/03 19:34:25 matt Exp $");
41 #endif /* LIBC_SCCS and not lint */
42
43 #include "namespace.h"
44 #include <sys/param.h>
45 #include <sys/types.h>
46 #include <ucontext.h>
47 #include <lwp.h>
48 #include <stdlib.h>
49
50 void
_lwp_makecontext(ucontext_t * u,void (* start)(void *),void * arg,void * tcb,caddr_t stack_base,size_t stack_size)51 _lwp_makecontext(ucontext_t *u, void (*start)(void *), void *arg,
52 void *tcb, caddr_t stack_base, size_t stack_size)
53 {
54 uintptr_t sp;
55
56 getcontext(u);
57 u->uc_link = NULL;
58
59 u->uc_stack.ss_sp = stack_base;
60 u->uc_stack.ss_size = stack_size;
61
62 sp = (uintptr_t)stack_base + stack_size;
63 sp -= STACK_ALIGNBYTES + 1;
64 sp &= ~STACK_ALIGNBYTES;
65
66 u->uc_mcontext.__gregs[_REG_RV] = (uintptr_t)arg; /* arg1 */
67 u->uc_mcontext.__gregs[_REG_SP] = (uintptr_t)sp; /* stack */
68 u->uc_mcontext.__gregs[_REG_LR] = (uintptr_t)_lwp_exit; /* LR */
69 u->uc_mcontext.__gregs[_REG_PC] = (uintptr_t)start; /* PC */
70 u->uc_mcontext.__gregs[_REG_TP] =
71 (uintptr_t)tcb + TLS_TP_OFFSET + sizeof(struct tls_tcb);
72 }
73