Refactor

src/io.rs

@@ -1,16 +1,25 @@
+//! 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::println;
 
 use alloc::format;
-use alloc::string::String;
+
 use log::{Level, Metadata, Record};
 use log::{LevelFilter, SetLoggerError};
 
 use crate::uart::write_uart;
 
-pub(crate) fn print(content: String) {
+/// 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) {
     write_uart(content);
 }
 
+/// Logger implementation that routes kernel log records to the UART-based console.
 struct Logger;
 
 impl log::Log for Logger {
@@ -39,6 +48,9 @@ impl log::Log for Logger {
 
 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))
 }