An x86_64 UEFI operating system.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 

64 lines
1.5 KiB

use crate::driver::tty::Tty;
use core::arch::asm;
/// A TTY attached via a serial port.
///
/// Serial ports don't commonly exist on physical devices anymore,
/// but many emulators support them and can map them to the host's TTY/terminal emulator,
/// which makes them useful for debugging in a VM.
pub struct SerialTty {
port: u16,
}
/// The port used by COM1 on x86 devices.
#[cfg(target_arch = "x86_64")]
pub const COM1_PORT: u16 = 0x3F8;
impl SerialTty {
/// Creates a new serial TTY which will use the provided port for output.
///
/// Unsafe because it is up to the caller to make sure
/// that the port is actually the port for a TTY device.
pub unsafe fn new(port: u16) -> SerialTty {
SerialTty {
port: port,
}
}
#[cfg(target_arch = "x86_64")]
fn outb(&self, cmd: u8) {
unsafe {
asm!("out dx, al", in("dx") self.port, in("al") cmd);
}
}
fn outc(&self, c: char) {
let len = c.len_utf8();
let bytes = (c as u32).to_le_bytes();
for i in 0..len {
self.outb(bytes[i]);
}
}
}
impl Tty for SerialTty {
fn putc(&mut self, c: char) {
self.outc(c);
}
fn puts(&mut self, s: &str) {
for c in s.chars() {
self.putc(c);
}
}
fn clear(&mut self) {
// VT100 escape code to reset the terminal: `ESC C`.
self.puts("\u{1B}c");
}
fn flush(&mut self) {
// This TTY doesn't use buffering.
}
}