Files
aios/kernel/src/console.rs
2025-07-05 14:31:39 +09:00

130 lines
3.0 KiB
Rust

//! Simple VGA console for AIOS v2
//! No external crates, pure Rust implementation
use core::fmt::{self, Write};
const VGA_BUFFER: *mut u16 = 0xb8000 as *mut u16;
const VGA_WIDTH: usize = 80;
const VGA_HEIGHT: usize = 25;
static mut CONSOLE: Console = Console {
col: 0,
row: 0,
color: 0x0f, // White on black
};
struct Console {
col: usize,
row: usize,
color: u8,
}
impl Console {
fn clear(&mut self) {
for i in 0..(VGA_WIDTH * VGA_HEIGHT) {
unsafe {
VGA_BUFFER.add(i).write_volatile(0x0f00); // Clear with white on black
}
}
self.col = 0;
self.row = 0;
}
fn write_byte(&mut self, byte: u8) {
match byte {
b'\n' => {
self.col = 0;
self.row += 1;
if self.row >= VGA_HEIGHT {
self.scroll_up();
}
}
byte => {
if self.col >= VGA_WIDTH {
self.col = 0;
self.row += 1;
if self.row >= VGA_HEIGHT {
self.scroll_up();
}
}
let pos = self.row * VGA_WIDTH + self.col;
let entry = (self.color as u16) << 8 | byte as u16;
unsafe {
VGA_BUFFER.add(pos).write_volatile(entry);
}
self.col += 1;
}
}
}
fn scroll_up(&mut self) {
// Move all lines up by one
for row in 1..VGA_HEIGHT {
for col in 0..VGA_WIDTH {
let pos = row * VGA_WIDTH + col;
let prev_pos = (row - 1) * VGA_WIDTH + col;
unsafe {
let entry = VGA_BUFFER.add(pos).read_volatile();
VGA_BUFFER.add(prev_pos).write_volatile(entry);
}
}
}
// Clear last line
for col in 0..VGA_WIDTH {
let pos = (VGA_HEIGHT - 1) * VGA_WIDTH + col;
unsafe {
VGA_BUFFER.add(pos).write_volatile(0x0f00);
}
}
self.row = VGA_HEIGHT - 1;
}
}
impl Write for Console {
fn write_str(&mut self, s: &str) -> fmt::Result {
for byte in s.bytes() {
self.write_byte(byte);
}
Ok(())
}
}
pub fn init() {
unsafe {
CONSOLE.clear();
}
}
pub fn print(s: &str) {
unsafe {
CONSOLE.write_str(s).unwrap();
}
}
#[macro_export]
macro_rules! kprint {
($($arg:tt)*) => {
$crate::console::_print(format_args!($($arg)*))
};
}
#[macro_export]
macro_rules! kprintln {
() => ($crate::console::print("\n"));
($($arg:tt)*) => ({
$crate::console::_print(format_args!($($arg)*));
$crate::console::print("\n");
})
}
#[doc(hidden)]
pub fn _print(args: fmt::Arguments) {
unsafe {
CONSOLE.write_fmt(args).unwrap();
}
}