1 use core::ops::{AddAssign, Deref, DerefMut, Shl, Sub};
3 use volatile::Volatile;
6 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
27 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
29 pub struct ColorCode(u8);
32 pub fn new(foreground: Color, background: Color) -> ColorCode {
33 ColorCode((background as u8).shl(4) | (foreground as u8))
37 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
41 color_code: ColorCode,
44 impl Deref for ScreenChar {
45 type Target = ScreenChar;
47 fn deref(&self) -> &Self::Target {
52 impl DerefMut for ScreenChar {
53 fn deref_mut(&mut self) -> &mut Self::Target {
58 const BUFFER_WIDTH: usize = 80;
59 const BUFFER_HEIGHT: usize = 25;
63 chars: [[Volatile<ScreenChar>; BUFFER_WIDTH]; BUFFER_HEIGHT],
68 column_position: usize,
69 color_code: ColorCode,
70 buffer: &'static mut Buffer,
75 pub fn write_byte(&mut self, byte: u8) {
77 b'\n' => self.new_line(),
79 if self.column_position >= BUFFER_WIDTH {
83 let row = self.row_position;
84 let col = self.column_position;
86 let color_code = self.color_code;
87 self.buffer.chars[row][col].write(ScreenChar {
88 ascii_character: byte,
92 self.column_position.add_assign(1);
98 pub fn write_string(&mut self, s: &str) {
99 for byte in s.bytes() {
101 // Printable ASCII character or \n
102 0x20..=0x7e | b'\n' => self.write_byte(byte),
103 // Not printable, write error char instead
104 _ => self.write_byte(0xfe),
110 fn new_line(&mut self) {
111 if self.row_position >= BUFFER_HEIGHT {
112 for row in 1..BUFFER_HEIGHT {
113 for col in 0..BUFFER_WIDTH {
114 let character = self.buffer.chars[row][col].read();
115 self.buffer.chars[row.sub(1)][col].write(character);
119 self.clear_row(BUFFER_HEIGHT.sub(1));
122 self.row_position.add_assign(1);
123 self.column_position = 0;
126 fn clear_row(&mut self, row: usize) {
127 let blank = ScreenChar {
128 ascii_character: b' ',
129 color_code: self.color_code,
132 for col in 0..BUFFER_WIDTH {
133 self.buffer.chars[row][col].write(blank);
138 pub fn test_print() {
139 let mut writer = Writer {
142 color_code: ColorCode::new(Color::Yellow, Color::Black),
143 buffer: unsafe { &mut *(0xb8000 as *mut Buffer) },
146 writer.write_string("Hello Stage2!");