Add a print_something function to print an `H` in the lower left

src/lib.rs

@@ -11,17 +11,7 @@ mod vga_buffer;
 pub extern fn rust_main() {
     // ATTENTION: we have a very small stack and no guard page
 
-    let hello = b"Hello World!";
-    let color_byte = 0x1f; // white foreground, blue background
-
-    let mut hello_colored = [color_byte; 24];
-    for (i, char_byte) in hello.into_iter().enumerate() {
-        hello_colored[i*2] = *char_byte;
-    }
-
-    // write `Hello World!` to the center of the VGA text buffer
-    let buffer_ptr = (0xb8000 + 1988) as *mut _;
-    unsafe { *buffer_ptr = hello_colored };
+    vga_buffer::print_something();
 
     loop{}
 }

src/vga_buffer.rs

@@ -79,3 +79,13 @@ impl Writer {
 
     fn new_line(&mut self) {/* TODO */}
 }
+
+pub fn print_something() {
+    let mut writer = Writer {
+        column_position: 0,
+        color_code: ColorCode::new(Color::LightGreen, Color::Black),
+        buffer: unsafe { Unique::new(0xb8000 as *mut _) },
+    };
+
+    writer.write_byte(b'H');
+}