[BSP] Update VFP code in armv6.

committed by FH.

libcpu/arm/armv6/vfp.c

@@ -0,0 +1,52 @@
+/*
+ * File      : vfp.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006, RT-Thread Develop Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2014-11-07     weety      first version
+ */
+
+#include <rthw.h>
+#include <rtthread.h>
+#include "vfp.h"
+
+#ifdef RT_USING_VFP
+
+void vfp_init(void)
+{
+    int ret = 0;
+    unsigned int value;
+    asm  volatile ("mrc p15, 0, %0, c1, c0, 2"
+            :"=r"(value)
+            :);
+    value |= 0xf00000;/*enable CP10, CP11 user access*/
+    asm volatile("mcr p15, 0, %0, c1, c0, 2"
+            :
+            :"r"(value));
+
+    asm volatile("fmrx %0, fpexc"
+            :"=r"(value));
+    value |=(1<<30);
+    asm volatile("fmxr fpexc, %0"
+            :
+            :"r"(value));
+
+}
+
+#endif