diff --git a/ch2/user/src/bin/00hello_world.rs b/ch2/user/src/bin/00hello_world.rs
index 6995fb6..e1391d7 100644
--- a/ch2/user/src/bin/00hello_world.rs
+++ b/ch2/user/src/bin/00hello_world.rs
@@ -5,6 +5,6 @@ use user_lib::*;
 
 #[no_mangle]
 fn main() -> i32 {
-    println!("123");
+    println!("hello 1");
     0
 }
\ No newline at end of file
diff --git a/ch2/user/src/bin/01hello_world.rs b/ch2/user/src/bin/01hello_world.rs
new file mode 100644
index 0000000..1e0f9bc
--- /dev/null
+++ b/ch2/user/src/bin/01hello_world.rs
@@ -0,0 +1,10 @@
+#![no_std]
+#![no_main]
+
+use user_lib::*;
+
+#[no_mangle]
+fn main() -> i32 {
+    println!("hello 2");
+    0
+}
\ No newline at end of file