添加rtthread相关代码

riscv/rtthread/components/utilities/rt-link/inc/rtlink_utils.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2021-05-15     Sherman      the first version
+ */
+#ifndef __RT_LINK_UTILITIES_H__
+#define __RT_LINK_UTILITIES_H__
+
+#include <rtthread.h>
+
+/* Calculate the number of '1' */
+int rt_link_utils_num1(rt_uint32_t n);
+
+rt_err_t rt_link_sf_crc32_reset(void);
+rt_uint32_t rt_link_sf_crc32(rt_uint8_t *data, rt_size_t len);
+
+#endif /* __RT_LINK_UTILITIES_H__ */