1 /*-
2 * Copyright (c) 2013 The NetBSD Foundation, Inc.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to The NetBSD Foundation
6 * by Matt Thomas of 3am Software Foundry.
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31
32 __RCSID("$NetBSD: arm_initfini.c,v 1.7 2013/09/08 13:15:53 matt Exp $");
33
34 #include "namespace.h"
35
36 /*
37 * To properly implement setjmp/longjmp for the ARM AAPCS ABI, it has to be
38 * aware of whether there is a FPU is present or not. Regardless of whether
39 * the hard-float ABI is being used, setjmp needs to save D8-D15. But it can
40 * only do this if those instructions won't cause an exception.
41 */
42
43 #include <sys/param.h>
44 #include <sys/sysctl.h>
45
46 #include <stdbool.h>
47 #include <stddef.h>
48
49 __dso_hidden int _libc_arm_fpu_present;
50 #ifndef __ARM_ARCH_EXT_IDIV__
51 __dso_hidden int _libc_arm_hwdiv_present;
52 #endif
53 static bool _libc_aapcs_initialized;
54
55 void _libc_aapcs_init(void) __attribute__((__constructor__, __used__));
56
57 void __section(".text.startup")
_libc_aapcs_init(void)58 _libc_aapcs_init(void)
59 {
60 if (!_libc_aapcs_initialized) {
61 #if !defined(__minix)
62 size_t len = sizeof(_libc_arm_fpu_present);
63 #endif
64 _libc_aapcs_initialized = true;
65 #if !defined(__minix)
66 (void)sysctlbyname("machdep.fpu_present",
67 &_libc_arm_fpu_present, &len, NULL, 0);
68 #ifndef __ARM_ARCH_EXT_IDIV__
69 (void)sysctlbyname("machdep.hwdiv_present",
70 &_libc_arm_hwdiv_present, &len, NULL, 0);
71 #endif
72 #endif /* !defined(__minix) */
73 }
74 }
75