hal/src/debug_uart.rs

//! Unsafe synchronous dump-string-to-uart impl and macro for debugging.

use core2::io::{Cursor, Write};
use core::fmt;

pub const TX_BUSY: *const u32 = 0x4000_0010 as *const u32;
pub const TX_PORT: *mut u32 = 0x4000_0018 as *mut u32;

pub fn send_sync(buf: &[u8], len: usize) {
    unsafe {
        for i in 0..len {
            while (TX_BUSY.read_volatile() & 1) != 0 {}
            TX_PORT.write_volatile(buf[i] as u32);
        }
    }
}

pub fn vdprintf(args: fmt::Arguments) {
    let mut uart_buf = [0u8; 256];
    let mut cur = Cursor::new(&mut uart_buf[..]);
    if cur.write_fmt(args).is_ok() {
        let pos = cur.position();
        send_sync(&uart_buf, pos as usize);
    }
}

#[macro_export]
macro_rules! dprintf {
    ($msg:expr) => ({
        $crate::debug_uart::vdprintf(format_args!($msg))
    });
    ($fmt:expr, $($arg:tt)+) => ({
        $crate::debug_uart::vdprintf(format_args!($fmt, $($arg)+))
    });
}