1/*-
2 * Copyright (c) 2013 The NetBSD Foundation, Inc.
3 * Copyright (c) 2013 Andrew Turner
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Matt Thomas of 3am Software Foundry.
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 *
18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 *
30 * Bases on NetBSD lib/libc/arch/arm/misc/arm_initfini.c
31 * $NetBSD: arm_initfini.c,v 1.2 2013/01/31 06:47:55 matt Exp $
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD$");
36
37/*
38 * To properly implement setjmp/longjmp for the ARM AAPCS ABI, it has to be
39 * aware of whether there is a FPU is present or not.  Regardless of whether
40 * the hard-float ABI is being used, setjmp needs to save D8-D15.  But it can
41 * only do this if those instructions won't cause an exception.
42 */
43
44#include <sys/param.h>
45#include <sys/sysctl.h>
46
47#include <stdbool.h>
48#include <stddef.h>
49
50extern int __sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
51    void *newp, size_t newlen);
52
53int _libc_arm_fpu_present;
54static bool _libc_aapcs_initialized;
55
56void	_libc_aapcs_init(void) __attribute__((__constructor__, __used__));
57
58void
59_libc_aapcs_init(void)
60{
61	int mib[2];
62	size_t len;
63
64	if (_libc_aapcs_initialized)
65		return;
66
67	mib[0] = CTL_HW;
68	mib[1] = HW_FLOATINGPT;
69
70	len = sizeof(_libc_arm_fpu_present);
71	if (__sysctl(mib, 2, &_libc_arm_fpu_present, &len, NULL, 0) == -1 ||
72	    len != sizeof(_libc_arm_fpu_present)) {
73		/* sysctl failed, assume no vfp */
74		_libc_arm_fpu_present = 0;
75	}
76
77	_libc_aapcs_initialized = true;
78}
79