136 lines
3.4 KiB
Rust
136 lines
3.4 KiB
Rust
use core::fmt;
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use lazy_static::lazy_static;
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use spin::Mutex;
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use x86_64::instructions::port::Port;
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const COM1: u16 = 0x3f8;
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#[allow(dead_code)]
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const COM2: u16 = 0x2f8;
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#[allow(dead_code)]
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const COM3: u16 = 0x3e8;
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#[allow(dead_code)]
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const COM4: u16 = 0x2e8;
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const ENABLE_TRANSMITTER: u8 = 0x1 << 1;
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const FIFO: u8 = 0x1;
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const TRIGGER_LVL_14: u8 = 0x3 << 6;
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const CLEAR_TRANSMIT_FIFO: u8 = 0x1 << 2;
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const CLEAR_RECEIVE_FIFO: u8 = 0x1 << 1;
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const NO_PARITY: u8 = 0x0;
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const EIGHT_BITS_LENGTH: u8 = 0x3;
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const EMPTY_TRANSMITTER: u8 = 0x1 << 5;
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const DLAB: u8 = 0x1 << 7;
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lazy_static! {
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pub static ref SERIAL1: Mutex<SerialPort> = {
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let mut serial_port = SerialPort::new(COM1);
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serial_port.init();
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Mutex::new(serial_port)
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};
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}
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#[doc(hidden)]
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pub fn _print(args: ::core::fmt::Arguments) {
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use core::fmt::Write;
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SERIAL1
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.lock()
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.write_fmt(args)
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.expect("Printing to serial failed");
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}
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/// Prints to the host through the serial interface.
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#[macro_export]
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macro_rules! serial_print {
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($($arg:tt)*) => {
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$crate::serial::_print(format_args!($($arg)*));
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};
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}
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/// Prints to the host through the serial interface, appending a newline.
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#[macro_export]
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macro_rules! serial_println {
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() => ($crate::serial_print!("\n"));
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($fmt:expr) => ($crate::serial_print!(concat!($fmt, "\n")));
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($fmt:expr, $($arg:tt)*) => ($crate::serial_print!(
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concat!($fmt, "\n"), $($arg)*));
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}
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pub struct SerialPort {
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base: Port<u8>,
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interrupt_enable: Port<u8>,
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fifo_control: Port<u8>,
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line_control: Port<u8>,
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line_status: Port<u8>,
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}
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impl SerialPort {
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pub fn new(port: u16) -> SerialPort {
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SerialPort {
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base: Port::new(port),
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interrupt_enable: Port::new(port + 1),
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fifo_control: Port::new(port + 2),
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line_control: Port::new(port + 3),
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line_status: Port::new(port + 5),
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}
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}
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fn write_byte(&mut self, byte: u8) -> bool {
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unsafe {
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let status: u8 = self.line_status.read();
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match status & EMPTY_TRANSMITTER {
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0 => false,
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_ => {
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self.base.write(byte);
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true
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}
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}
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}
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}
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fn write_string(&mut self, s: &str) -> usize {
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let mut len: usize = 0;
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for byte in s.bytes() {
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let written: bool = self.write_byte(byte);
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if !written {
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return len;
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}
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len += 1;
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}
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len
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}
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fn init_baud_rate(&mut self) {
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let line: u8;
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unsafe {
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line = self.line_control.read();
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self.line_control.write(line | DLAB);
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self.base.write(3);
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self.interrupt_enable.write(0);
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self.line_control.write(line);
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}
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}
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fn init(&mut self) {
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self.init_baud_rate();
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unsafe {
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self.line_control.write(NO_PARITY | EIGHT_BITS_LENGTH);
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self.fifo_control
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.write(FIFO | TRIGGER_LVL_14 | CLEAR_TRANSMIT_FIFO | CLEAR_RECEIVE_FIFO);
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self.interrupt_enable.write(ENABLE_TRANSMITTER);
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}
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}
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}
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impl fmt::Write for SerialPort {
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fn write_str(&mut self, s: &str) -> fmt::Result {
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let len: usize = self.write_string(s);
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match len {
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l if l == s.len() => Ok(()),
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_ => Err(fmt::Error),
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}
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}
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}
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