diff --git a/kernel/Cargo.lock b/kernel/Cargo.lock
index 15dc395..f2ba0ff 100644
--- a/kernel/Cargo.lock
+++ b/kernel/Cargo.lock
@@ -78,7 +78,7 @@ source = "git+https://github.com/myrrlyn/bitvec.git#8ab20a3e33fe068fc3a4a05eda12
 [[package]]
 name = "bootloader"
 version = "0.4.0"
-source = "git+https://github.com/rcore-os/bootloader#18e4fec0d82e8a5571abceb69d1d11fc0edccba1"
+source = "git+https://github.com/rcore-os/bootloader?branch=vga#adc3ceda509e18b0d5a5623473dab4f8801a2551"
 dependencies = [
  "apic 0.1.0 (git+https://github.com/rcore-os/apic-rs)",
  "fixedvec 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -354,7 +354,7 @@ dependencies = [
  "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitmap-allocator 0.1.0 (git+https://github.com/rcore-os/bitmap-allocator)",
  "bitvec 0.11.0 (git+https://github.com/myrrlyn/bitvec.git)",
- "bootloader 0.4.0 (git+https://github.com/rcore-os/bootloader)",
+ "bootloader 0.4.0 (git+https://github.com/rcore-os/bootloader?branch=vga)",
  "buddy_system_allocator 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "cc 1.0.31 (registry+https://github.com/rust-lang/crates.io-index)",
  "console-traits 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -650,7 +650,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum bitmap-allocator 0.1.0 (git+https://github.com/rcore-os/bitmap-allocator)" = "<none>"
 "checksum bitvec 0.11.0 (git+https://github.com/myrrlyn/bitvec.git)" = "<none>"
 "checksum bitvec 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cfadef5c4e2c2e64067b9ecc061179f12ac7ec65ba613b1f60f3972bbada1f5b"
-"checksum bootloader 0.4.0 (git+https://github.com/rcore-os/bootloader)" = "<none>"
+"checksum bootloader 0.4.0 (git+https://github.com/rcore-os/bootloader?branch=vga)" = "<none>"
 "checksum buddy_system_allocator 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "59da15ef556589ee78370281d75b67f2d69ed26465ec0e0f3961e2021502426f"
 "checksum byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a019b10a2a7cdeb292db131fc8113e57ea2a908f6e7894b0c3c671893b65dbeb"
 "checksum cc 1.0.31 (registry+https://github.com/rust-lang/crates.io-index)" = "c9ce8bb087aacff865633f0bd5aeaed910fe2fe55b55f4739527f2e023a2e53d"
diff --git a/kernel/Cargo.toml b/kernel/Cargo.toml
index 9547d31..f7562f8 100644
--- a/kernel/Cargo.toml
+++ b/kernel/Cargo.toml
@@ -70,7 +70,7 @@ rcore-fs = { git = "https://github.com/rcore-os/rcore-fs" }
 rcore-fs-sfs = { git = "https://github.com/rcore-os/rcore-fs" }
 
 [target.'cfg(target_arch = "x86_64")'.dependencies]
-bootloader = { git = "https://github.com/rcore-os/bootloader" }
+bootloader = { git = "https://github.com/rcore-os/bootloader", branch="vga", features=["vga_320x200"] }
 apic = { git = "https://github.com/rcore-os/apic-rs" }
 x86_64 = "0.5"
 raw-cpuid = "6.0"
diff --git a/kernel/src/arch/x86_64/io.rs b/kernel/src/arch/x86_64/io.rs
index c78b014..a25c655 100644
--- a/kernel/src/arch/x86_64/io.rs
+++ b/kernel/src/arch/x86_64/io.rs
@@ -10,18 +10,18 @@ pub fn getchar() -> char {
 }
 
 pub fn putfmt(fmt: Arguments) {
-    #[cfg(feature = "nographic")]
-    {
+    //#[cfg(feature = "nographic")]
+    //{
         unsafe {
             COM1.force_unlock();
         }
         COM1.lock().write_fmt(fmt).unwrap();
-    }
-    #[cfg(not(feature = "nographic"))]
-    {
-        unsafe {
-            VGA_WRITER.force_unlock();
-        }
-        VGA_WRITER.lock().write_fmt(fmt).unwrap();
-    }
+    //}
+    //#[cfg(not(feature = "nographic"))]
+    //{
+        //unsafe {
+            //VGA_WRITER.force_unlock();
+        //}
+        //VGA_WRITER.lock().write_fmt(fmt).unwrap();
+    //}
 }
diff --git a/kernel/src/arch/x86_64/mod.rs b/kernel/src/arch/x86_64/mod.rs
index 2d0e6ca..c0087ec 100644
--- a/kernel/src/arch/x86_64/mod.rs
+++ b/kernel/src/arch/x86_64/mod.rs
@@ -54,6 +54,17 @@ pub extern "C" fn _start(boot_info: &'static BootInfo) -> ! {
     crate::process::init();
     // wake up other CPUs
     AP_CAN_INIT.store(true, Ordering::Relaxed);
+    unsafe{
+        use crate::consts::KERNEL_OFFSET;
+        use core::slice;
+        let frame_buffer_data =
+            unsafe { slice::from_raw_parts_mut((KERNEL_OFFSET + 0xf000_0000) as *mut u8, 64000 as usize) };
+        for x in 0..320 { 
+            for y in 0..200 {
+                frame_buffer_data[x + y * 320] = (x % 16 + ( y % 16) * 16) as u8;
+            }
+        }
+    }
     // call the first main function in kernel.
     crate::kmain();
 }