learning-simple-os/src/vga_buffer.rs
Mahdi Dibaiee cb472d22d8 fix(boot): fix page table bits
feat(print): print macro
2016-06-25 18:36:00 +04:30

139 lines
2.6 KiB
Rust

use core::ptr::Unique;
use core::fmt::Write;
use spin::Mutex;
#[allow(dead_code)]
#[repr(u8)]
pub enum Color {
Black = 0,
Blue = 1,
Green = 2,
Cyan = 3,
Red = 4,
Magenta = 5,
Brown = 6,
LightGray = 7,
DarkGray = 8,
LightBlue = 9,
LightGreen = 10,
LightCyan = 11,
LightRed = 12,
Pink = 13,
Yellow = 14,
White = 15,
}
#[derive(Clone, Copy)]
struct ColorCode(u8);
impl ColorCode {
const fn new(foreground: Color, background: Color) -> ColorCode {
ColorCode((background as u8) << 4 | (foreground as u8))
}
}
#[repr(C)]
#[derive(Clone, Copy)]
struct ScreenChar {
ascii_character: u8,
color_code: ColorCode,
}
const BUFFER_HEIGHT: usize = 25;
const BUFFER_WIDTH: usize = 80;
struct Buffer {
chars: [[ScreenChar; BUFFER_WIDTH]; BUFFER_HEIGHT],
}
pub struct Writer {
column_position: usize,
color_code: ColorCode,
buffer: Unique<Buffer>,
}
impl Writer {
pub fn write_byte(&mut self, byte: u8) {
match byte {
b'\n' => self.new_line(),
byte => {
if self.column_position >= BUFFER_WIDTH {
self.new_line();
}
let row = BUFFER_HEIGHT - 1;
let col = self.column_position;
self.buffer().chars[row][col] = ScreenChar {
ascii_character: byte,
color_code: self.color_code,
};
self.column_position += 1;
}
}
}
pub fn write_str(&mut self, s: &str) {
for byte in s.bytes() {
self.write_byte(byte);
}
}
fn buffer(&mut self) -> &mut Buffer {
unsafe { self.buffer.get_mut() }
}
fn new_line(&mut self) {
for row in 0..(BUFFER_HEIGHT-1) {
let buffer = self.buffer();
buffer.chars[row] = buffer.chars[row + 1]
}
self.clear_row(BUFFER_HEIGHT - 1);
self.column_position = 0;
}
fn clear_row(&mut self, row: usize) {
let blank = ScreenChar {
ascii_character: b' ',
color_code: self.color_code,
};
self.buffer().chars[row] = [blank; BUFFER_WIDTH];
}
}
impl ::core::fmt::Write for Writer {
fn write_str(&mut self, s: &str) -> ::core::fmt::Result {
for byte in s.bytes() {
self.write_byte(byte)
}
Ok(())
}
}
pub static WRITER: Mutex<Writer> = Mutex::new(Writer {
column_position: 0,
color_code: ColorCode::new(Color::LightCyan, Color::Black),
buffer: unsafe { Unique::new(0xb8000 as *mut _) },
});
macro_rules! print {
($($arg:tt)*) => ({
use core::fmt::Write;
let mut writer = $crate::vga_buffer::WRITER.lock();
writer.write_fmt(format_args!($($arg)*)).unwrap();
});
}
macro_rules! println {
($fmt:expr) => (print!(concat!($fmt, "\n")));
($fmt:expr, $($arg:tt)*) => (print!(concat!($fmt, "\n"), $($arg)*));
}
pub fn clear_screen() {
for _ in 0..BUFFER_HEIGHT {
println!("");
}
}