diff --git a/kernel/src/objects/tcb.rs b/kernel/src/objects/tcb.rs
index 9955bb3..18162ab 100644
--- a/kernel/src/objects/tcb.rs
+++ b/kernel/src/objects/tcb.rs
@@ -6,6 +6,7 @@ use core::fmt::Debug;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use uapi::cap::ObjectType;
 use uapi::fault::Fault;
+use uapi::syscall::*;
 use utils::{
     addr::*,
     linked_list::{Link, LinkHelper},
@@ -124,19 +125,6 @@ impl TcbObject {
         self.state
     }
 
-    pub fn tid(&self) -> usize {
-        self.tid
-    }
-
-    pub fn schedulable(&self) -> bool {
-        matches!(self.state, ThreadState::Idle | ThreadState::Running)
-    }
-
-    pub fn schedule_next(&self) {
-        self.sched_queue.detach();
-        SCHEDULER.add_next(self);
-    }
-
     pub fn set_state(&mut self, state: ThreadState) {
         self.state = state;
     }
@@ -157,6 +145,19 @@ impl TcbObject {
         self.time_tick = self.time_tick.saturating_sub(1);
     }
 
+    pub fn tid(&self) -> usize {
+        self.tid
+    }
+
+    pub fn schedulable(&self) -> bool {
+        matches!(self.state, ThreadState::Idle | ThreadState::Running)
+    }
+
+    pub fn schedule_next(&self) {
+        self.sched_queue.detach();
+        SCHEDULER.add_next(self);
+    }
+
     pub fn activate_vspace(&self) {
         let cap = TableCap::try_from(&self.vspace).expect("activate_vspace: invalid cap");
         let paddr = cap.as_object::<Level0>().paddr();
@@ -169,6 +170,10 @@ impl TcbObject {
         self.trapframe.handle_trap(false);
     }
 
+    pub fn get_message_info(&self) -> SysResult<MessageInfo> {
+        MessageInfo::try_from(self.trapframe.get_reg(REG_MESSAGE_INFO))
+    }
+
     pub fn handle_syscall(&mut self) {
         // TODO: don't panic here, return error to user instead, create SysRespInfo
         handle_syscall(self).unwrap();
diff --git a/kernel/src/syscall.rs b/kernel/src/syscall.rs
index 3250a10..e943c50 100644
--- a/kernel/src/syscall.rs
+++ b/kernel/src/syscall.rs
@@ -11,7 +11,7 @@ macro_rules! assert_length {
 }
 
 pub fn handle_syscall(tcb: &mut TcbObject) -> SysResult {
-    let info = MessageInfo::try_from(tcb.trapframe.get_reg(REG_MESSAGE_INFO))?;
+    let info = tcb.get_message_info()?;
 
     // Invalid, Debug*, Yield will bypass the capability check
     match info.label() {