建立工程，成功创建两个虚拟串口

source/rt_thread/libcpu/arm/armv6/vfp.c

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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