1 /* $NetBSD: _lwp.c,v 1.7 2012/03/21 00:34:04 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 #if defined(LIBC_SCCS) && !defined(lint)
31 __RCSID("$NetBSD: _lwp.c,v 1.7 2012/03/21 00:34:04 christos Exp $");
32 #endif /* LIBC_SCCS and not lint */
33
34 #include "namespace.h"
35 #include <sys/types.h>
36 #include <ucontext.h>
37 #include <lwp.h>
38 #include <stdlib.h>
39
40 void
_lwp_makecontext(ucontext_t * u,void (* start)(void *),void * arg,void * private,caddr_t stack_base,size_t stack_size)41 _lwp_makecontext(ucontext_t *u, void (*start)(void *), void *arg,
42 void *private, caddr_t stack_base, size_t stack_size)
43 {
44 __greg_t *gr;
45 unsigned long *sp;
46
47 getcontext(u);
48 gr = u->uc_mcontext.__gregs;
49
50 u->uc_link = NULL;
51
52 u->uc_stack.ss_sp = stack_base;
53 u->uc_stack.ss_size = stack_size;
54
55
56 sp = (void *)(stack_base + stack_size);
57 sp = (ulong *)((ulong)sp & ~0x07);
58
59 /* Make room for the fake caller stack frame (CCFSZ, only in words) */
60 sp -= 8 + 8 + 1 + 6 + 1;
61
62 /* Entering (*start)(arg), return is to _lwp_exit */
63 gr[_REG_PC] = (ulong) start;
64 gr[_REG_nPC] = (ulong) start + 4;
65 gr[_REG_O0] = (ulong)arg;
66 gr[_REG_O6] = (ulong)sp;
67 gr[_REG_O7] = (ulong)_lwp_exit - 8;
68 gr[_REG_G7] = (ulong)private;
69
70 /* XXX: uwe: why do we need this? */
71 /* create loopback in the window save area on the stack? */
72 sp[8+6] = (ulong)sp; /* %i6 */
73 sp[8+7] = (ulong)_lwp_exit - 8; /* %i7 */
74 }
75