diff --git a/src/rtm.c b/src/rtm.c
index 70f86facb8..a0bafee0c7 100644
--- a/src/rtm.c
+++ b/src/rtm.c
@@ -170,8 +170,10 @@ RTM_EXPORT(__aeabi_idiv)
 RTM_EXPORT(__aeabi_uidivmod)
 RTM_EXPORT(__aeabi_d2iz)
 RTM_EXPORT(strcmp)
+RTM_EXPORT(strlen)
 RTM_EXPORT(rand)
 RTM_EXPORT(memset)
+RTM_EXPORT(memcpy)
 
 #ifdef RT_USING_NEWLIB
 
@@ -181,6 +183,10 @@ RTM_EXPORT(snprintf)
 RTM_EXPORT(access)
 RTM_EXPORT(__assert_func)
 
+#include <time.h>
+RTM_EXPORT(localtime)
+RTM_EXPORT(time)
+
 #endif
 
 #ifdef RT_USING_RTGUI