src/arch/riscv64/io/uart.rs


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use core::fmt;
use core::fmt::Write;

pub fn _print(args: fmt::Arguments) {
    // Not thread safe but no dependencies
    let mut stdout = Stdout;
    fmt::write(&mut stdout, args);
}

struct Stdout;
impl Write for Stdout {
    fn write_str(&mut self, s: &str) -> fmt::Result {
        print_string(s);
        Ok(())
    }
}

pub fn print_string(s: &str) {
    let uart_base = 0x10000000 as *mut u8;
    while unsafe { uart_base.add(5).read_volatile() } & 0x20 == 0 {}

    for c in s.chars() {
        unsafe {
            uart_base.write_volatile(c as u8);
        }
    }
}