1/*-
2 * Copyright (c) 2015 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Andrew Turner under
6 * sponsorship from the FreeBSD Foundation.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD$");
32
33#include <sys/param.h>
34
35#include <machine/armreg.h>
36
37#include <inttypes.h>
38#include <stdarg.h>
39#include <stdlib.h>
40#include <ucontext.h>
41
42void _ctx_start(void);
43
44void
45ctx_done(ucontext_t *ucp)
46{
47
48	if (ucp->uc_link == NULL) {
49		exit(0);
50	} else {
51		setcontext((const ucontext_t *)ucp->uc_link);
52		abort();
53	}
54}
55
56__weak_reference(__makecontext, makecontext);
57
58void
59__makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
60{
61	struct gpregs *gp;
62	va_list ap;
63	int i;
64
65	/* A valid context is required. */
66	if (ucp == NULL)
67		return;
68
69	if ((argc < 0) || (argc > 8))
70		return;
71
72	gp = &ucp->uc_mcontext.mc_gpregs;
73
74	va_start(ap, argc);
75	/* Pass up to eight arguments in x0-7. */
76	for (i = 0; i < argc && i < 8; i++)
77		gp->gp_x[i] = va_arg(ap, uint64_t);
78	va_end(ap);
79
80	/* Set the stack */
81	gp->gp_sp = STACKALIGN(ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
82	/* Arrange for return via the trampoline code. */
83	gp->gp_elr = (__register_t)_ctx_start;
84	gp->gp_x[19] = (__register_t)func;
85	gp->gp_x[20] = (__register_t)ucp;
86}
87