Files
illuminance/src/driver/serial.rs
T
2026-08-21 15:24:31 -04:00

52 lines
1.0 KiB
Rust

use core::arch::asm;
const SERIAL_COM1: u16 = 0x3F8;
pub unsafe fn init() {
outb(SERIAL_COM1 + 1, 0x00); // Disable interrupts
outb(SERIAL_COM1 + 3, 0x80);
outb(SERIAL_COM1, 0x03); // 38400 baud (divisor = 3)
outb(SERIAL_COM1 + 1, 0x00);
outb(SERIAL_COM1 + 3, 0x03);
outb(SERIAL_COM1 + 2, 0xC7);
outb(SERIAL_COM1 + 4, 0x0B);
}
pub unsafe fn write_byte(byte: u8) {
while (inb(SERIAL_COM1 + 5) & 0x20) == 0 {}
outb(SERIAL_COM1, byte);
}
pub unsafe fn write_bytes(bytes: &[u8]) {
for &byte in bytes {
write_byte(byte);
}
}
pub unsafe fn write_str(string: &str) {
write_bytes(string.as_bytes());
}
unsafe fn outb(port: u16, value: u8) {
asm!(
"out dx, al",
in("dx") port,
in("al") value,
options(nostack, nomem, preserves_flags)
);
}
unsafe fn inb(port: u16) -> u8 {
let value: u8;
unsafe {
asm!("in al, dx",in("dx") port,out("al") value,options(nostack, nomem, preserves_flags));
}
value
}