diff --git a/bsp/abstract-machine/src/libc.c b/bsp/abstract-machine/src/libc.c
index a85f3b4..cdd0bff 100644
--- a/bsp/abstract-machine/src/libc.c
+++ b/bsp/abstract-machine/src/libc.c
@@ -1,9 +1,10 @@
 #include <klib.h>
+#include <rtthread.h>
 
 char *strchr(const char *s, int c) {
   assert(0);
 }
 
 char *strstr(const char *haystack, const char *needle) {
-  assert(0);
+  return rt_strstr(haystack, needle);
 }
diff --git a/bsp/abstract-machine/src/uart.c b/bsp/abstract-machine/src/uart.c
index f732a12..c44b06a 100644
--- a/bsp/abstract-machine/src/uart.c
+++ b/bsp/abstract-machine/src/uart.c
@@ -37,8 +37,8 @@ static int _uart_putc(struct rt_serial_device *serial, char c) {
 }
 
 static int _uart_getc(struct rt_serial_device *serial) {
-  assert(0);
-  return -1;
+  static const char *p = "help\n";
+  return (*p != '\0' ? *(p ++) : -1);
 }
 
 const struct rt_uart_ops _uart_ops = {