xref: /freebsd/lib/libc/arm/gen/arm_initfini.c (revision 8e03dd5926db3d6af789021aa0422c209a531670)
1*8e03dd59SAndrew Turner /*-
2*8e03dd59SAndrew Turner  * Copyright (c) 2013 The NetBSD Foundation, Inc.
3*8e03dd59SAndrew Turner  * Copyright (c) 2013 Andrew Turner
4*8e03dd59SAndrew Turner  * All rights reserved.
5*8e03dd59SAndrew Turner  *
6*8e03dd59SAndrew Turner  * This code is derived from software contributed to The NetBSD Foundation
7*8e03dd59SAndrew Turner  * by Matt Thomas of 3am Software Foundry.
8*8e03dd59SAndrew Turner  *
9*8e03dd59SAndrew Turner  * Redistribution and use in source and binary forms, with or without
10*8e03dd59SAndrew Turner  * modification, are permitted provided that the following conditions
11*8e03dd59SAndrew Turner  * are met:
12*8e03dd59SAndrew Turner  * 1. Redistributions of source code must retain the above copyright
13*8e03dd59SAndrew Turner  *    notice, this list of conditions and the following disclaimer.
14*8e03dd59SAndrew Turner  * 2. Redistributions in binary form must reproduce the above copyright
15*8e03dd59SAndrew Turner  *    notice, this list of conditions and the following disclaimer in the
16*8e03dd59SAndrew Turner  *    documentation and/or other materials provided with the distribution.
17*8e03dd59SAndrew Turner  *
18*8e03dd59SAndrew Turner  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19*8e03dd59SAndrew Turner  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20*8e03dd59SAndrew Turner  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21*8e03dd59SAndrew Turner  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22*8e03dd59SAndrew Turner  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23*8e03dd59SAndrew Turner  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24*8e03dd59SAndrew Turner  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25*8e03dd59SAndrew Turner  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26*8e03dd59SAndrew Turner  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27*8e03dd59SAndrew Turner  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28*8e03dd59SAndrew Turner  * POSSIBILITY OF SUCH DAMAGE.
29*8e03dd59SAndrew Turner  *
30*8e03dd59SAndrew Turner  * Bases on NetBSD lib/libc/arch/arm/misc/arm_initfini.c
31*8e03dd59SAndrew Turner  * $NetBSD: arm_initfini.c,v 1.2 2013/01/31 06:47:55 matt Exp $
32*8e03dd59SAndrew Turner  */
33*8e03dd59SAndrew Turner 
34*8e03dd59SAndrew Turner #include <sys/cdefs.h>
35*8e03dd59SAndrew Turner __FBSDID("$FreeBSD$");
36*8e03dd59SAndrew Turner 
37*8e03dd59SAndrew Turner /*
38*8e03dd59SAndrew Turner  * To properly implement setjmp/longjmp for the ARM AAPCS ABI, it has to be
39*8e03dd59SAndrew Turner  * aware of whether there is a FPU is present or not.  Regardless of whether
40*8e03dd59SAndrew Turner  * the hard-float ABI is being used, setjmp needs to save D8-D15.  But it can
41*8e03dd59SAndrew Turner  * only do this if those instructions won't cause an exception.
42*8e03dd59SAndrew Turner  */
43*8e03dd59SAndrew Turner 
44*8e03dd59SAndrew Turner #include <sys/param.h>
45*8e03dd59SAndrew Turner #include <sys/sysctl.h>
46*8e03dd59SAndrew Turner 
47*8e03dd59SAndrew Turner #include <stdbool.h>
48*8e03dd59SAndrew Turner #include <stddef.h>
49*8e03dd59SAndrew Turner 
50*8e03dd59SAndrew Turner extern int __sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
51*8e03dd59SAndrew Turner     void *newp, size_t newlen);
52*8e03dd59SAndrew Turner 
53*8e03dd59SAndrew Turner int _libc_arm_fpu_present;
54*8e03dd59SAndrew Turner static bool _libc_aapcs_initialized;
55*8e03dd59SAndrew Turner 
56*8e03dd59SAndrew Turner void	_libc_aapcs_init(void) __attribute__((__constructor__, __used__));
57*8e03dd59SAndrew Turner 
58*8e03dd59SAndrew Turner void
59*8e03dd59SAndrew Turner _libc_aapcs_init(void)
60*8e03dd59SAndrew Turner {
61*8e03dd59SAndrew Turner 	int mib[2];
62*8e03dd59SAndrew Turner 	size_t len;
63*8e03dd59SAndrew Turner 
64*8e03dd59SAndrew Turner 	if (_libc_aapcs_initialized)
65*8e03dd59SAndrew Turner 		return;
66*8e03dd59SAndrew Turner 
67*8e03dd59SAndrew Turner 	mib[0] = CTL_HW;
68*8e03dd59SAndrew Turner 	mib[1] = HW_FLOATINGPT;
69*8e03dd59SAndrew Turner 
70*8e03dd59SAndrew Turner 	len = sizeof(_libc_arm_fpu_present);
71*8e03dd59SAndrew Turner 	if (__sysctl(mib, 2, &_libc_arm_fpu_present, &len, NULL, 0) == -1 ||
72*8e03dd59SAndrew Turner 	    len != sizeof(_libc_arm_fpu_present)) {
73*8e03dd59SAndrew Turner 		/* sysctl failed, assume no vfp */
74*8e03dd59SAndrew Turner 		_libc_arm_fpu_present = 0;
75*8e03dd59SAndrew Turner 	}
76*8e03dd59SAndrew Turner 
77*8e03dd59SAndrew Turner 	_libc_aapcs_initialized = true;
78*8e03dd59SAndrew Turner }
79