diff --git a/kernel/src/drivers/gpu/fb.rs b/kernel/src/drivers/gpu/fb.rs
index 1939b901..de278afd 100644
--- a/kernel/src/drivers/gpu/fb.rs
+++ b/kernel/src/drivers/gpu/fb.rs
@@ -173,6 +173,11 @@ impl Framebuffer {
         unsafe { self.buf.base_addr }
     }
 
+    #[inline]
+    pub fn framebuffer_size(&self) -> usize {
+        self.fb_info.screen_size as usize
+    }
+
     #[inline]
     pub fn bus_addr(&self) -> usize {
         self.fb_info.bus_addr as usize
diff --git a/kernel/src/fs/file.rs b/kernel/src/fs/file.rs
index b5429e63..db4f84e8 100644
--- a/kernel/src/fs/file.rs
+++ b/kernel/src/fs/file.rs
@@ -1,8 +1,8 @@
 //! File handle for process
 
+use crate::thread;
 use alloc::{string::String, sync::Arc};
 use core::fmt;
-use crate::thread;
 
 use rcore_fs::vfs::{FsError, INode, Metadata, PollStatus, Result};
 
diff --git a/kernel/src/fs/vga.rs b/kernel/src/fs/vga.rs
index 3f34116f..95b03859 100755
--- a/kernel/src/fs/vga.rs
+++ b/kernel/src/fs/vga.rs
@@ -31,15 +31,20 @@ impl INode for Vga {
     }
     fn write_at(&self, _offset: usize, _buf: &[u8]) -> Result<usize> {
         info!("the _offset is {} {}", _offset, _buf[0]);
-        use core::slice;
-        let frame_buffer_data = unsafe {
-            slice::from_raw_parts_mut(
-                phys_to_virt(0xfd00_0000) as *mut u8,
-                (1024 * 768 * 3) as usize,
-            )
-        };
-        frame_buffer_data.copy_from_slice(&_buf);
-        return Ok(1024 * 768 * 3);
+        let lock = FRAME_BUFFER.lock();
+        if let Some(ref frame_buffer) = *lock {
+            use core::slice;
+            let frame_buffer_data = unsafe {
+                slice::from_raw_parts_mut(
+                    frame_buffer.base_addr() as *mut u8,
+                    frame_buffer.framebuffer_size(),
+                )
+            };
+            frame_buffer_data.copy_from_slice(&_buf);
+            Ok(frame_buffer.framebuffer_size())
+        } else {
+            Err(FsError::EntryNotFound)
+        }
     }
     fn poll(&self) -> Result<PollStatus> {
         Ok(PollStatus {