// SPDX-License-Identifier: MIT OR Apache-2.0
//
// Copyright (c) 2018-2023 Andre Richter <andre.o.richter@gmail.com>

//! BSP console facilities.

use crate::console;
use core::fmt;

//--------------------------------------------------------------------------------------------------
// Private Definitions
//--------------------------------------------------------------------------------------------------

/// A mystical, magical device for generating QEMU output out of the void.
struct QEMUOutput;

//--------------------------------------------------------------------------------------------------
// Private Code
//--------------------------------------------------------------------------------------------------

/// Implementing `core::fmt::Write` enables usage of the `format_args!` macros, which in turn are
/// used to implement the `kernel`'s `print!` and `println!` macros. By implementing `write_str()`,
/// we get `write_fmt()` automatically.
///
/// See [`src/print.rs`].
///
/// [`src/print.rs`]: ../../print/index.html
impl fmt::Write for QEMUOutput {
    fn write_str(&mut self, s: &str) -> fmt::Result {
        for c in s.chars() {
            unsafe {
                core::ptr::write_volatile(0x3F20_1000 as *mut u8, c as u8);
            }
        }

        Ok(())
    }
}

//--------------------------------------------------------------------------------------------------
// Public Code
//--------------------------------------------------------------------------------------------------

/// Return a reference to the console.
pub fn console() -> impl console::interface::Write {
    QEMUOutput {}
}