diff --git a/kernel/src/console.rs b/kernel/src/console.rs
index 64912a1..ce345ac 100644
--- a/kernel/src/console.rs
+++ b/kernel/src/console.rs
@@ -14,6 +14,10 @@ impl Console {
 
 impl Write for Console {
   fn write_str(&mut self, s: &str) -> fmt::Result {
-    todo!()
+    // TODO: Lock
+
+    Ok(())
+
+    // TODO: Release lock
   }
 }
diff --git a/kernel/src/main.rs b/kernel/src/main.rs
index aca4640..04d937b 100644
--- a/kernel/src/main.rs
+++ b/kernel/src/main.rs
@@ -5,6 +5,7 @@ use core::fmt::Write;
 use core::{arch::global_asm, ptr};
 
 use crate::console::Console;
+use crate::memory_layout::UART0;
 
 #[macro_use]
 mod macros;
@@ -18,11 +19,10 @@ mod uart;
 global_asm!(include_str!("start.s"));
 
 #[no_mangle]
-pub extern "C" fn not_main() {
-  let mut console = Console::init();
-  let _ = writeln!(console, "eos0 is booting...");
+pub extern "C" fn main() {
+  // let mut console = Console::init();
+  // let _ = writeln!(console, "eos0 is booting...");
 
-  const UART0: *mut u8 = 0x0900_0000 as *mut u8;
   let out_str = b"AArch64 Bare Metal";
   for byte in out_str {
     unsafe {
diff --git a/kernel/src/memory_layout.rs b/kernel/src/memory_layout.rs
index 50e15b3..947a0e1 100644
--- a/kernel/src/memory_layout.rs
+++ b/kernel/src/memory_layout.rs
@@ -1 +1 @@
-pub const UART0: u64 = 0x0900_0000;
+pub const UART0: *mut u8 = 0x0900_0000 as *mut u8;
diff --git a/kernel/src/start.s b/kernel/src/start.s
index 40680ed..88f0196 100644
--- a/kernel/src/start.s
+++ b/kernel/src/start.s
@@ -6,7 +6,7 @@
 _start:
     ldr     x30, =LD_STACK_PTR
     mov     sp, x30
-    bl      not_main
+    bl      main
 
 .equ PSCI_SYSTEM_OFF, 0x84000008
 .globl system_off
diff --git a/kernel/src/uart.rs b/kernel/src/uart.rs
index 6f756fe..a9d1db4 100644
--- a/kernel/src/uart.rs
+++ b/kernel/src/uart.rs
@@ -1,3 +1,5 @@
+//! UART (Universal Asynchronous Receiver-Transmitter)
+
 use crate::memory_layout::UART0;
 
 /// http://byterunner.com/16550.html
@@ -14,7 +16,8 @@ impl Register {
 /// address of one of the registers
 #[inline]
 fn register(reg: Register) -> *mut u8 {
-  (UART0 + reg.offset()) as *mut u8
+  // (UART0 + reg.offset()) as *mut u8
+  UART0
 }
 
 #[inline]
diff --git a/run.sh b/run.sh
index 26df59f..3a62632 100755
--- a/run.sh
+++ b/run.sh
@@ -1,5 +1,5 @@
 set -euo pipefail
-cargo build
+cargo xbuild --target=aarch64-unknown-none.json
 exec qemu-system-aarch64 \
   -machine virt \
   -m 1024M \