Finish pulling in the NetBSD setjmp/longjmp updates on ARM.

Store/restore the VFP registers in setjmp/longjmp on ARM EABI if VFP is
enabled in the kernel. It checks the hw.floatingpoint sysctl to see if
floating-point is available and uses this to determine if it should store
them. If it does it uses a different magic value so longjmp is able to know
if it should load them.

1 files changed, 78 insertions, 0 deletions

diff --git a/lib/libc/arm/gen/arm_initfini.c b/lib/libc/arm/gen/arm_initfini.c
new file mode 100644
index 0000000..9def8c8
--- /dev/null
+++ b/lib/libc/arm/gen/arm_initfini.c
@@ -0,0 +1,78 @@
+/*-
+ * Copyright (c) 2013 The NetBSD Foundation, Inc.
+ * Copyright (c) 2013 Andrew Turner
+ * 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.
+ * 
+ * Bases on NetBSD lib/libc/arch/arm/misc/arm_initfini.c
+ * $NetBSD: arm_initfini.c,v 1.2 2013/01/31 06:47:55 matt Exp $
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * 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>
+
+extern int __sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
+    void *newp, size_t newlen);
+
+int _libc_arm_fpu_present;
+static bool _libc_aapcs_initialized;
+
+void	_libc_aapcs_init(void) __attribute__((__constructor__, __used__));
+
+void
+_libc_aapcs_init(void)
+{
+	int mib[2];
+	size_t len;
+
+	if (_libc_aapcs_initialized)
+		return;
+
+	mib[0] = CTL_HW;
+	mib[1] = HW_FLOATINGPT;
+
+	len = sizeof(_libc_arm_fpu_present);
+	if (__sysctl(mib, 2, &_libc_arm_fpu_present, &len, NULL, 0) == -1 ||
+	    len != sizeof(_libc_arm_fpu_present)) {
+		/* sysctl failed, assume no vfp */
+		_libc_arm_fpu_present = 0;
+	}
+
+	_libc_aapcs_initialized = true;
+}