diff --git a/kernel/src/objects/tcb.rs b/kernel/src/objects/tcb.rs
index 771910a..b83a692 100644
--- a/kernel/src/objects/tcb.rs
+++ b/kernel/src/objects/tcb.rs
@@ -1,5 +1,6 @@
 use super::{
     cap::{CapEntry, RawCap},
+    cnode::CNodeCap,
     null::NullCap,
     Cap, KernelObject,
 };
@@ -7,14 +8,15 @@ use crate::{
     arch::{layout::mmap_phys_to_virt, trap::TrapContext},
     plat::trap::TrapContextOps,
 };
-use uapi::cap::ObjectType;
+use core::fmt::Debug;
+use uapi::{cap::ObjectType, error::SysResult, fault::Fault, syscall::MessageInfo};
 use utils::{
     addr::*,
     linked_list::{Link, LinkHelper},
     LinkHelperImpl,
 };
 
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 pub enum ThreadState {
     Inactive,
     Running,
@@ -27,10 +29,13 @@ pub enum ThreadState {
 pub struct TcbObject {
     pub trapframe: TrapContext, // must be the first field
 
-    cspace: CapEntry,
-    vspace: CapEntry,
+    cspace:        CapEntry,
+    vspace:        CapEntry,
+    notification:  CapEntry,
+    buffer:        CapEntry, // CapFrame
+    fault:         Fault,
+    fault_handler: CapEntry,
 
-    // TODO: add reply, buffer, fault, caller ... priority, dom
     state:     ThreadState,
     time_tick: usize,
     pub link:  Link<Self>,
@@ -41,12 +46,16 @@ LinkHelperImpl!(TcbObject:link);
 impl TcbObject {
     pub fn new() -> Self {
         Self {
-            trapframe: TrapContext::default(),
-            cspace:    CapEntry::new(NullCap::mint()),
-            vspace:    CapEntry::new(NullCap::mint()),
-            state:     ThreadState::Inactive,
-            time_tick: 0,
-            link:      Link::default(),
+            trapframe:     TrapContext::default(),
+            cspace:        CapEntry::new(NullCap::mint()),
+            vspace:        CapEntry::new(NullCap::mint()),
+            notification:  CapEntry::new(NullCap::mint()),
+            buffer:        CapEntry::new(NullCap::mint()),
+            fault:         Fault::Null,
+            fault_handler: CapEntry::new(NullCap::mint()),
+            state:         ThreadState::Inactive,
+            time_tick:     0,
+            link:          Link::default(),
         }
     }
 
@@ -55,6 +64,14 @@ impl TcbObject {
         self.state = ThreadState::Idle;
     }
 
+    pub fn state(&self) -> ThreadState {
+        self.state
+    }
+
+    pub fn set_state(&mut self, state: ThreadState) {
+        self.state = state;
+    }
+
     pub fn timetick(&self) -> usize {
         self.time_tick
     }
@@ -79,7 +96,19 @@ impl TcbObject {
     }
 
     pub fn handle_syscall(&mut self) {
-        todo!("TcbObject::handle_syscall");
+        let handle_syscall_inner = || -> SysResult {
+            let info = MessageInfo::try_from(self.trapframe.get_reg(0))?;
+
+            let cspace = CNodeCap::try_from(&self.cspace)?;
+            let cap_ptr = self.trapframe.get_reg(1);
+            let cap = cspace.resolve_address_bits(cap_ptr, usize::BITS as usize);
+
+            todo!("handle_syscall");
+
+            Ok(())
+        };
+
+        handle_syscall_inner().unwrap();
     }
 }
 
@@ -108,3 +137,19 @@ impl<'a> TcbCap<'a> {
         }
     }
 }
+
+impl Debug for TcbCap<'_> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        let obj = self.as_object();
+        f.debug_struct("TcbCap")
+            .field("cspace", &obj.cspace)
+            .field("vspace", &obj.vspace)
+            .field("notification", &obj.notification)
+            .field("buffer", &obj.buffer)
+            .field("fault", &obj.fault)
+            .field("fault_handler", &obj.fault_handler)
+            .field("state", &obj.state)
+            .field("time_tick", &obj.time_tick)
+            .finish()
+    }
+}