diff --git a/ch3-coop/os/src/batch.rs b/ch3-coop/os/src/batch.rs
index 559a257..a42c9e9 100644
--- a/ch3-coop/os/src/batch.rs
+++ b/ch3-coop/os/src/batch.rs
@@ -2,6 +2,7 @@ use core::arch::asm;
 use lazy_static::*;
 use riscv::register::mcause::Trap;
 use crate::println;
+use crate::sbi::shutdown;
 use crate::sync::UPSafeCell;
 use crate::trap::TrapContext;
 
@@ -64,31 +65,6 @@ impl AppManager{
             );
         }
     }
-
-    // 把app_idx位置的app 加载到指定的内存APP_BASE_ADDRESS位置
-    unsafe fn load_app(&self, app_idx: usize){
-        if app_idx >= self.num_app{
-            panic!("All applications completed!")
-        }
-        // 清空app执行区域的内存
-        core::slice::from_raw_parts_mut(APP_BASE_ADDRESS as *mut u8, APP_SIZE_LIMIT).fill(0);
-
-        // 得到指定app_idx位置的数据(下一个位置的开始 - 需要运行app的开始 = 需要运行app的内存大小
-        let app_src = core::slice::from_raw_parts(self.app_start_lis[app_idx] as *const u8,
-                                                  self.app_start_lis[app_idx + 1] - self.app_start_lis[app_idx]);
-
-        // 把app的代码 copy到指定的运行的区域
-        let app_len = app_src.len();
-        if app_len > APP_SIZE_LIMIT {
-            panic!("app memory overrun!")
-        }
-        core::slice::from_raw_parts_mut(APP_BASE_ADDRESS as *mut u8, app_len)
-            .copy_from_slice(app_src);
-
-        // 刷新cache
-        asm!("fence.i");
-    }
-
 }
 
 
@@ -97,18 +73,17 @@ pub fn init() {
 }
 
 pub fn run_next_app() -> ! {
-    // 运行一个新的app
-    // 把需要执行的指定app, 加载到执行位置APP_BASE_ADDRESS
-    // app_manager 需要drop 或者在一个作用域中, 因为这个函数不会返回, 后面直接进入用户态了
-    {
-        let mut app_manager = APP_MANAGER.exclusive_access();
-        unsafe{
-            app_manager.load_app(app_manager.current_app);
-
-            println!("------------- run_next_app load app {}", app_manager.current_app);
-        }
-        app_manager.current_app += 1;
+    // 得到下一个需要运行的app的入口地址
+    let mut app_manager = APP_MANAGER.exclusive_access();
+    let current_app = app_manager.current_app;
+    if current_app >= app_manager.num_app {
+        shutdown();
     }
+    let app_entry_ptr = app_manager.app_start_lis[current_app];
+    println!("------------- run_next_app load app {}, {:x}", current_app, app_entry_ptr);
+    app_manager.current_app += 1;
+    drop(app_manager);
+
 
     extern "C" {
         fn __restore(trap_context_ptr: usize);
@@ -118,7 +93,7 @@ pub fn run_next_app() -> ! {
         // 得到用户栈的栈顶
         let user_stack_top = USER_STACK.as_ptr() as usize + USER_STACK_SIZE;
         // 得到用户trap的上下文以及寄存器状态
-        let user_trap_context = TrapContext::app_init_context(APP_BASE_ADDRESS, user_stack_top);
+        let user_trap_context = TrapContext::app_init_context(app_entry_ptr, user_stack_top);
 
         // 把用户trap copy到内核栈
         let kernel_stack_top = KERNEL_STACK.as_ptr() as usize + KERNEL_STACK_SIZE;  // 现在栈顶和栈底都在一个内存位置
diff --git a/ch3-coop/os/src/loader.rs b/ch3-coop/os/src/loader.rs
index b5fa6d5..2fa5b83 100644
--- a/ch3-coop/os/src/loader.rs
+++ b/ch3-coop/os/src/loader.rs
@@ -9,7 +9,7 @@ extern "C" {
 // 得到用户app的数量
 fn get_num_app() -> usize{
     unsafe{
-        _num_app as usize as *const usize.read_volatile()
+        (_num_app as usize as *const usize).read_volatile()
     }
 }
 
@@ -27,7 +27,7 @@ pub fn load_app() {
     };
 
     // 清除缓存
-    unsafe { asm!("fence.i" :::: "volatile"); }
+    unsafe { asm!("fence.i"); }
 
     // 加载app
     for app_id in 0..num_app {
diff --git a/ch3-coop/os/src/main.rs b/ch3-coop/os/src/main.rs
index ffc78a9..bb76f3f 100644
--- a/ch3-coop/os/src/main.rs
+++ b/ch3-coop/os/src/main.rs
@@ -8,9 +8,9 @@ use lang_items::console;
 
 pub mod lang_items;
 pub mod sbi;
-// pub mod batch;
+pub mod batch;
 pub mod sync;
-// pub mod trap;
+pub mod trap;
 pub mod syscall;
 pub mod loader;
 pub mod config;
@@ -39,9 +39,12 @@ pub fn rust_main(){
     println!("boot_stack_top_bound: {:#x}, boot_stack_lower_bound: {:#x}", boot_stack_top_bound as usize, boot_stack_lower_bound as usize);
 
     loader::load_app();
-    // trap::init();
-    // batch::init();
-    // batch::run_next_app();
+    trap::init();
+    batch::init();
+    batch::run_next_app();
+    loop {
+
+    }
 }
 
 /// ## 初始化bss段
diff --git a/ch3-coop/user/src/bin/00write_a.rs b/ch3-coop/user/src/bin/00write_a.rs
index 3303899..67088ed 100644
--- a/ch3-coop/user/src/bin/00write_a.rs
+++ b/ch3-coop/user/src/bin/00write_a.rs
@@ -13,7 +13,7 @@ fn main() -> i32 {
             print!("A");
         }
         println!(" [{}/{}]", i + 1, HEIGHT);
-        sys_yield();
+        // sys_yield();
     }
     println!("Test write_a OK!");
     0
diff --git a/ch3-coop/user/src/bin/01write_b.rs b/ch3-coop/user/src/bin/01write_b.rs
index 64bd665..1ae798f 100644
--- a/ch3-coop/user/src/bin/01write_b.rs
+++ b/ch3-coop/user/src/bin/01write_b.rs
@@ -13,7 +13,7 @@ fn main() -> i32 {
             print!("B");
         }
         println!(" [{}/{}]", i + 1, HEIGHT);
-        sys_yield();
+        // sys_yield();
     }
     println!("Test write_b OK!");
     0
diff --git a/ch3-coop/user/src/bin/02write_c.rs b/ch3-coop/user/src/bin/02write_c.rs
index 25464bf..f9c8f71 100644
--- a/ch3-coop/user/src/bin/02write_c.rs
+++ b/ch3-coop/user/src/bin/02write_c.rs
@@ -13,7 +13,7 @@ fn main() -> i32 {
             print!("C");
         }
         println!(" [{}/{}]", i + 1, HEIGHT);
-        sys_yield();
+        // sys_yield();
     }
     println!("Test write_c OK!");
     0