Crate uart_16550

Minimal support for serial communication through UART devices, which are compatible to the 16550 UART.

This crate supports I/O port-mapped (x86 only) and memory-mapped UARTS.

Usage

Depending on the system architecture, the UART can be either accessed through port-mapped I/O or memory-mapped I/O.

With port-mappd I/O

The UART is accessed through port-mapped I/O on architectures such as x86_64. On these architectures, the SerialPort type can be used:

use uart_16550::SerialPort;

const SERIAL_IO_PORT: u16 = 0x3F8;

let mut serial_port = unsafe { SerialPort::new(SERIAL_IO_PORT) };
serial_port.init();

// Now the serial port is ready to be used. To send a byte:
serial_port.send(42);

// To receive a byte:
let data = serial_port.receive();

With memory mapped serial port

Most other architectures, such as RISC-V, use memory-mapped I/O for accessing the UARTs. On these architectures, the MmioSerialPort type can be used:

use uart_16550::MmioSerialPort;

const SERIAL_PORT_BASE_ADDRESS: usize = 0x1000_0000;

let mut serial_port = unsafe { MmioSerialPort::new(SERIAL_PORT_BASE_ADDRESS) };
serial_port.init();

// Now the serial port is ready to be used. To send a byte:
serial_port.send(42);

// To receive a byte:
let data = serial_port.receive();

Structs

MmioSerialPort

A memory-mapped UART.

SerialPort

A x86 I/O port-mapped UART.

WouldBlockError

The WouldBlockError error indicates that the serial device was not ready immediately.