minix/lib/libc/arch/arm/misc/arm_initfini.c

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/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: arm_initfini.c,v 1.7 2013/09/08 13:15:53 matt Exp $");
#include "namespace.h"
/*
* To properly implement setjmp/longjmp for the ARM AAPCS ABI, it has to be
* aware of whether there is a FPU is present or not. Regardless of whether
* the hard-float ABI is being used, setjmp needs to save D8-D15. But it can
* only do this if those instructions won't cause an exception.
*/
#include <sys/param.h>
#include <sys/sysctl.h>
#include <stdbool.h>
#include <stddef.h>
__dso_hidden int _libc_arm_fpu_present;
#ifndef __ARM_ARCH_EXT_IDIV__
__dso_hidden int _libc_arm_hwdiv_present;
#endif
static bool _libc_aapcs_initialized;
void _libc_aapcs_init(void) __attribute__((__constructor__, __used__));
void __section(".text.startup")
_libc_aapcs_init(void)
{
if (!_libc_aapcs_initialized) {
size_t len = sizeof(_libc_arm_fpu_present);
_libc_aapcs_initialized = true;
#if !defined(__minix)
(void)sysctlbyname("machdep.fpu_present",
&_libc_arm_fpu_present, &len, NULL, 0);
#ifndef __ARM_ARCH_EXT_IDIV__
(void)sysctlbyname("machdep.hwdiv_present",
&_libc_arm_hwdiv_present, &len, NULL, 0);
#endif
#endif /* !defined(__minix) */
}
}