update

components/libc/compilers/newlib/minilib.c

@@ -16,3 +16,16 @@ void * _sbrk_r(struct _reent *ptr, ptrdiff_t incr)
     /* no use this routine to get memory */
     return RT_NULL;
 }
+
+#ifdef RT_USING_HEAP
+char *strdup(const char *s)
+{
+    size_t len = strlen(s) + 1;
+    char *tmp = (char *)rt_malloc(len);
+
+    if(!tmp) return NULL;
+
+    rt_memcpy(tmp, s, len);
+    return tmp;
+}
+#endif /*RT_USING_HEAP*/