diff --git a/crate/process/src/thread.rs b/crate/process/src/thread.rs
index 1c8b1ad..7ffa0e6 100644
--- a/crate/process/src/thread.rs
+++ b/crate/process/src/thread.rs
@@ -40,7 +40,7 @@ pub fn current() -> Thread {
 /// Puts the current thread to sleep for the specified amount of time.
 pub fn sleep(dur: Duration) {
     let time = dur_to_ticks(dur);
-    info!("sleep: {:?} ticks", time);
+    trace!("sleep: {:?} ticks", time);
     processor().manager().sleep(current().id(), time);
     park();
 
@@ -58,7 +58,7 @@ pub fn spawn<F, T>(f: F) -> JoinHandle<T>
         F: Send + 'static + FnOnce() -> T,
         T: Send + 'static,
 {
-    info!("spawn:");
+    trace!("spawn:");
 
     // 注意到下面的问题：
     // Processor只能从入口地址entry+参数arg创建新线程
@@ -108,13 +108,13 @@ pub fn spawn<F, T>(f: F) -> JoinHandle<T>
 
 /// Cooperatively gives up a timeslice to the OS scheduler.
 pub fn yield_now() {
-    info!("yield:");
+    trace!("yield:");
     processor().yield_now();
 }
 
 /// Blocks unless or until the current thread's token is made available.
 pub fn park() {
-    info!("park:");
+    trace!("park:");
     processor().manager().sleep(current().id(), 0);
     processor().yield_now();
 }
diff --git a/kernel/src/arch/riscv32/interrupt.rs b/kernel/src/arch/riscv32/interrupt.rs
index bad1812..2229845 100644
--- a/kernel/src/arch/riscv32/interrupt.rs
+++ b/kernel/src/arch/riscv32/interrupt.rs
@@ -16,6 +16,8 @@ pub fn init() {
         stvec::write(__alltraps as usize, stvec::TrapMode::Direct);
         // Enable IPI
         sie::set_ssoft();
+        // Enable serial interrupt
+        sie::set_sext();
     }
     info!("interrupt: init end");
 }
@@ -44,6 +46,7 @@ pub extern fn rust_trap(tf: &mut TrapFrame) {
     use super::riscv::register::scause::{Trap, Interrupt as I, Exception as E};
     trace!("Interrupt @ CPU{}: {:?} ", super::cpu::id(), tf.scause.cause());
     match tf.scause.cause() {
+        Trap::Interrupt(I::SupervisorExternal) => serial(),
         Trap::Interrupt(I::SupervisorSoft) => ipi(),
         Trap::Interrupt(I::SupervisorTimer) => timer(),
         Trap::Exception(E::IllegalInstruction) => illegal_inst(tf),
@@ -53,6 +56,10 @@ pub extern fn rust_trap(tf: &mut TrapFrame) {
     trace!("Interrupt end");
 }
 
+fn serial() {
+    ::trap::serial(super::io::getchar());
+}
+
 fn ipi() {
     debug!("IPI");
     super::bbl::sbi::clear_ipi();
diff --git a/kernel/src/arch/x86_64/driver/serial.rs b/kernel/src/arch/x86_64/driver/serial.rs
index 182e733..fb39899 100644
--- a/kernel/src/arch/x86_64/driver/serial.rs
+++ b/kernel/src/arch/x86_64/driver/serial.rs
@@ -29,7 +29,6 @@ impl SerialRead for SerialPort {
             let ports = self as *mut _ as *mut [Pio<u8>; 6];
             let line_sts = &(*ports)[5];
             let data = &(*ports)[0];
-            while line_sts.read() & 1 != 1 {}
             data.read()
         }
     }
diff --git a/kernel/src/arch/x86_64/interrupt/handler.rs b/kernel/src/arch/x86_64/interrupt/handler.rs
index a9e9ecf..7c727d7 100644
--- a/kernel/src/arch/x86_64/interrupt/handler.rs
+++ b/kernel/src/arch/x86_64/interrupt/handler.rs
@@ -131,6 +131,7 @@ fn keyboard() {
 fn com1() {
     use arch::driver::serial::*;
     trace!("\nInterupt: COM1");
+    ::trap::serial(COM1.lock().receive() as char);
 }
 
 fn com2() {
diff --git a/kernel/src/console.rs b/kernel/src/console.rs
index 9f6efbd..178b268 100644
--- a/kernel/src/console.rs
+++ b/kernel/src/console.rs
@@ -1,11 +1,13 @@
 use core::ops::Deref;
 use alloc::string::String;
-use arch::io::getchar;
+use alloc::collections::VecDeque;
+use sync::Condvar;
+use sync::SpinNoIrqLock as Mutex;
 
 pub fn get_line() -> String {
     let mut s = String::new();
     loop {
-        let c = getchar();
+        let c = get_char();
         match c {
             '\u{7f}' /* '\b' */ => {
                 if s.pop().is_some() {
@@ -23,4 +25,34 @@ pub fn get_line() -> String {
             _ => {}
         }
     }
-}
\ No newline at end of file
+}
+
+#[derive(Default)]
+pub struct InputQueue {
+    buf: Mutex<VecDeque<char>>,
+    pushed: Condvar,
+}
+
+impl InputQueue {
+    pub fn push(&self, c: char) {
+        self.buf.lock().push_back(c);
+        self.pushed.notify_one();
+    }
+    pub fn pop(&self) -> char {
+        loop {
+            let ret = self.buf.lock().pop_front();
+            match ret {
+                Some(c) => return c,
+                None => self.pushed._wait(),
+            }
+        }
+    }
+}
+
+lazy_static! {
+    pub static ref CONSOLE_INPUT: InputQueue = InputQueue::default();
+}
+
+pub fn get_char() -> char {
+    CONSOLE_INPUT.pop()
+}
diff --git a/kernel/src/trap.rs b/kernel/src/trap.rs
index 529fd20..acfd17a 100644
--- a/kernel/src/trap.rs
+++ b/kernel/src/trap.rs
@@ -5,10 +5,10 @@ use arch::cpu;
 pub static mut TICK: usize = 0;
 
 pub fn timer() {
-    processor().tick();
     if cpu::id() == 0 {
         unsafe { TICK += 1; }
     }
+    processor().tick();
 }
 
 pub fn error(tf: &TrapFrame) -> ! {
@@ -19,4 +19,8 @@ pub fn error(tf: &TrapFrame) -> ! {
     processor().manager().exit(pid, 0x100);
     processor().yield_now();
     unreachable!();
+}
+
+pub fn serial(c: char) {
+    ::console::CONSOLE_INPUT.push(c);
 }
\ No newline at end of file
diff --git a/riscv-pk/machine/uart16550.c b/riscv-pk/machine/uart16550.c
index fe1ba99..93fbb43 100644
--- a/riscv-pk/machine/uart16550.c
+++ b/riscv-pk/machine/uart16550.c
@@ -57,6 +57,8 @@ static void uart16550_done(const struct fdt_scan_node *node, void *extra)
   uart16550[1] = 0x00;    //                  (hi byte)
   uart16550[3] = 0x03;    // 8 bits, no parity, one stop bit
   uart16550[2] = 0xC7;    // Enable FIFO, clear them, with 14-byte threshold
+  uart16550[4] = 0x0B;
+  uart16550[1] = 0x01;    // Enable interrupt
 }
 
 void query_uart16550(uintptr_t fdt)