Files
riscv64-kernel/src/io.rs

80 lines
2.1 KiB
Rust

//! Kernel I/O helpers and logging frontend.
//!
//! Provides a lightweight logger implementation routing to UART and helper
//! macros for printing from kernel code.
use crate::print;
use crate::tty::{TTY_INITIALIZED, TTY0};
use alloc::format;
use io::Write;
use log::{Level, Metadata, Record};
use log::{LevelFilter, SetLoggerError};
use crate::uart::write_uart;
/// Print a string to the kernel console (via UART).
///
/// Accepts any type that implements `AsRef<str>` to avoid unnecessary
/// allocations at call sites.
pub(crate) fn print<T: AsRef<str>>(content: T) {
if TTY_INITIALIZED.load(core::sync::atomic::Ordering::Relaxed) {
unsafe { TTY0.new_node().write(content.as_ref().as_bytes()).unwrap() };
} else {
write_uart(&content);
}
}
/// Logger implementation that routes kernel log records to the UART-based console.
pub struct Logger;
impl log::Log for Logger {
fn enabled(&self, metadata: &Metadata) -> bool {
metadata.level() <= Level::Info
}
fn log(&self, record: &Record) {
if self.enabled(record.metadata()) {
let to_print = if let Some((file, line)) = record.file().zip(record.line()) {
format!(
"[{}] at {}:{} - {}\n",
record.level(),
file,
line,
record.args()
)
} else {
format!("[{}] - {}\n", record.level(), record.args())
};
print!("{to_print}");
}
}
fn flush(&self) {}
}
pub static LOGGER: Logger = Logger;
/// Initialize the kernel logger and set the default level.
///
/// Returns an error if a global logger has already been set.
pub fn init_log() -> Result<(), SetLoggerError> {
log::set_logger(&LOGGER).map(|()| log::set_max_level(LevelFilter::Info))
}
#[macro_export]
macro_rules! print {
($($args:expr),*) => {
$crate::io::print(alloc::format!($($args),*))
};
}
#[macro_export]
macro_rules! println {
() => {
$crate::print!("\n")
};
($($args:expr),*) => {{
$crate::print!("{}\n", alloc::format!($($args),*));
}};
}