Use volatile writes for printing to screen

Cargo.toml

@@ -8,3 +8,4 @@ crate-type = ["staticlib"]
 
 [dependencies]
 rlibc = "1.0"
+volatile = "0.1.0"

src/lib.rs

@@ -4,6 +4,7 @@
 #![no_std]
 
 extern crate rlibc;
+extern crate volatile;
 
 mod vga_buffer;
 

src/vga_buffer.rs

@@ -1,4 +1,5 @@
 use core::ptr::Unique;
+use volatile::Volatile;
 
 #[allow(dead_code)]
 #[derive(Debug, Clone, Copy)]
@@ -42,7 +43,7 @@ const BUFFER_HEIGHT: usize = 25;
 const BUFFER_WIDTH: usize = 80;
 
 struct Buffer {
-    chars: [[ScreenChar; BUFFER_WIDTH]; BUFFER_HEIGHT],
+    chars: [[Volatile<ScreenChar>; BUFFER_WIDTH]; BUFFER_HEIGHT],
 }
 
 pub struct Writer {
@@ -64,10 +65,10 @@ impl Writer {
                 let col = self.column_position;
 
                 let color_code = self.color_code;
-                self.buffer().chars[row][col] = ScreenChar {
+                self.buffer().chars[row][col].write(ScreenChar {
                     ascii_character: byte,
                     color_code: color_code,
-                };
+                });
                 self.column_position += 1;
             }
         }