diff --git a/bootloader/rustsbi-k210.bin b/bootloader/rustsbi-k210.bin
index e696137a..58d1c1a7 100755
Binary files a/bootloader/rustsbi-k210.bin and b/bootloader/rustsbi-k210.bin differ
diff --git a/bootloader/rustsbi-qemu.bin b/bootloader/rustsbi-qemu.bin
index 5ccab433..f293ced7 100755
Binary files a/bootloader/rustsbi-qemu.bin and b/bootloader/rustsbi-qemu.bin differ
diff --git a/user/src/bin/00hello_world.rs b/user/src/bin/00hello_world.rs
index 684396a2..7a11980a 100644
--- a/user/src/bin/00hello_world.rs
+++ b/user/src/bin/00hello_world.rs
@@ -1,5 +1,6 @@
 #![no_std]
 #![no_main]
+#![feature(llvm_asm)]
 
 #[macro_use]
 extern crate user_lib;
@@ -7,5 +8,8 @@ extern crate user_lib;
 #[no_mangle]
 fn main() -> i32 {
     println!("Hello, world!");
+    unsafe {
+        llvm_asm!("sret");
+    }
     0
 }
\ No newline at end of file