diff --git a/os/src/main.rs b/os/src/main.rs
index 3801a01e..c5ae3652 100644
--- a/os/src/main.rs
+++ b/os/src/main.rs
@@ -54,8 +54,8 @@ pub fn rust_main() -> ! {
     trap::enable_timer_interrupt();
     timer::set_next_trigger();
     task::stackless_coroutine::kernel_stackless_coroutine_test();
-    task::kernel_stackful_coroutine_test();
     fs::list_apps();
+    task::kernel_stackful_coroutine_test();
     task::add_initproc();
     task::run_tasks();
     panic!("Unreachable in rust_main!");
diff --git a/os/src/task/context.rs b/os/src/task/context.rs
index 73d7b319..8bb8b6f3 100644
--- a/os/src/task/context.rs
+++ b/os/src/task/context.rs
@@ -16,14 +16,6 @@ impl TaskContext {
         }
     }
 
-    pub fn kthread_init() -> Self {
-        Self {
-            ra: 0xAAAAAAAA,
-            sp: 0xBBBBBBBB,
-            s: [0xCCCCCCCC; 12],
-        }
-    }
-
     pub fn goto_trap_return(kstack_ptr: usize) -> Self {
         Self {
             ra: trap_return as usize,
diff --git a/os/src/task/id.rs b/os/src/task/id.rs
index 8257b178..0d8fc5b3 100644
--- a/os/src/task/id.rs
+++ b/os/src/task/id.rs
@@ -1,6 +1,6 @@
 use super::ProcessControlBlock;
 use crate::config::{KERNEL_STACK_SIZE, PAGE_SIZE, TRAMPOLINE, TRAP_CONTEXT_BASE, USER_STACK_SIZE};
-use crate::mm::{MapPermission, PhysPageNum, VirtAddr, KERNEL_SPACE};
+use crate::mm::{MapPermission, PhysPageNum, VirtAddr, KERNEL_SPACE, PhysAddr};
 use crate::sync::UPSafeCell;
 use alloc::{
     sync::{Arc, Weak},
@@ -70,6 +70,7 @@ pub struct KernelStack(pub usize);
 pub fn kstack_alloc() -> KernelStack {
     let kstack_id = KSTACK_ALLOCATOR.exclusive_access().alloc();
     let (kstack_bottom, kstack_top) = kernel_stack_position(kstack_id);
+    //println!("kstack_alloc  kstack_bottom: {:#x?}, kstack_top: {:#x?}", kstack_bottom, kstack_top);
     KERNEL_SPACE.exclusive_access().insert_framed_area(
         kstack_bottom.into(),
         kstack_top.into(),
@@ -82,6 +83,8 @@ impl Drop for KernelStack {
     fn drop(&mut self) {
         let (kernel_stack_bottom, _) = kernel_stack_position(self.0);
         let kernel_stack_bottom_va: VirtAddr = kernel_stack_bottom.into();
+        // let kernel_stack_bottom_pa: PhysAddr = kernel_stack_bottom.into();
+        // println!("kstack_drop  kstack_bottom: va: {:#x?}, pa: {:#x?}", kernel_stack_bottom_va, kernel_stack_bottom_pa);
         KERNEL_SPACE
             .exclusive_access()
             .remove_area_with_start_vpn(kernel_stack_bottom_va.into());
diff --git a/os/src/task/mod.rs b/os/src/task/mod.rs
index 990b1dce..2ef79b97 100644
--- a/os/src/task/mod.rs
+++ b/os/src/task/mod.rs
@@ -138,12 +138,12 @@ pub fn kthread_create(f: fn()) {
 
     println!("kthread_create");
     
-    //�����ں��߳�
+    // create kernel thread
     let new_tcb = TaskControlBlock::create_kthread(f);
     // let kernel_stack = new_tcb.get_kernel_stack();
     let new_task = Arc::new(new_tcb);
 
-    //��������������,���û��̷߳���һ�����.
+    // add kernel thread into TASK_MANAGER
     // println!("add task");
     add_task(Arc::clone(&new_task));
 }
diff --git a/os/src/task/task.rs b/os/src/task/task.rs
index 839a4e21..22037320 100644
--- a/os/src/task/task.rs
+++ b/os/src/task/task.rs
@@ -23,11 +23,6 @@ impl TaskControlBlock {
         let inner = process.inner_exclusive_access();
         inner.memory_set.token()
     }
-
-    // pub fn get_kernel_stack(&self) -> usize {
-    //     self.kstack
-    // }
-
 }
 
 pub struct TaskControlBlockInner {
@@ -83,7 +78,7 @@ impl TaskControlBlock {
         let kernelstack = crate::task::id::KStack::new();
         let kstack_top = kernelstack.top();
 
-        let mut context = TaskContext::kthread_init();
+        let mut context = TaskContext::zero_init();
         let context_addr = &context as *const TaskContext as usize;
         let pa = PhysAddr::from(context_addr);
         let context_ppn = pa.floor();
@@ -91,11 +86,12 @@ impl TaskControlBlock {
         context.ra = f as usize;
         context.sp = kstack_top;
 
-        println!("context ppn :{:#x?}", context_ppn);
+        //println!("context ppn :{:#x?}", context_ppn);
 
         Self {
             process,
-            kstack,
+            kstack:KernelStack(kstack_top),
+            //kstack,
             inner: unsafe {
                 UPSafeCell::new(TaskControlBlockInner {
                     res: None,