You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: io.rs
    path of file: ./repos/OpenSK/boards/nordic/nrf52840_mdk_dfu/src
    
    the code of the file until where you have to start completion: use core::fmt::Write;
use core::panic::PanicInfo;
use cortexm4;
use kernel::debug;
use kernel::debug::IoWrite;
use kernel::hil::led;
use kernel::hil::uart::{self, Configure};
use nrf52840::gpio::Pin;

use crate::{CHIP, PROCESSES, PROCESS_PRINTER};

struct Writer {
    initialized: bool,
}

static mut WRITER: Writer = Writer { initialized: false };

impl Write for Writer {
    fn write_str(&mut self, s: &str) -> ::core::fmt::Result {
        self.write(s.as_bytes());
        Ok(())
    }
}

impl IoWrite for Writer {
    fn write(&mut self, buf: &[u8]) {
        //
    
    fn write(&mut self, buf: &[u8]) {
        // Here, we create a second instance of the Uarte struct.
        // This is okay because we only call this during a panic, and
        // we will never actually process the interrupts
        let uart = nrf52840::uart::Uarte::new();
        if !self.initialized {
            self.initialized = true;
            let _ = uart.configure(uart::Parameters {
                baud_rate: 115200,
                stop_bits: uart::StopBits::One,
                parity: uart::Parity::None,
                hw_flow_control: false,
                width: uart::Width::Eight,
            });
        }
        for &c in buf {
            unsafe {
                uart.send_byte(c);
            }
            while !uart.tx_ready() {}
        }
    }