diff --git a/src/main.rs b/src/main.rs
index 777816d..4135497 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -17,7 +17,7 @@ unsafe extern "C" fn _enter() -> ! {
         // load hartid into t0; if t0 =/= 0, then jump to busy loop
         "csrr t0, mhartid",
         "bnez t0, 3f",
-        
+
         // before we use the `la` pseudo-instruction for the first time,
         // we need to set `gp` (look up linker relaxation)
         ".option push", // pushes the current option stack
@@ -73,8 +73,10 @@ extern "C" fn start() -> ! {
     unsafe { uart::init_console(0x1000_0000) };
     println!("Hello, world!");
 
+    // print current hartid
     println!("hartid: {}", riscv::register::mhartid::read());
 
+    // poll console for input and print characters back
     loop {
         let c = uart::CONSOLE.lock().as_mut().and_then(uart::Device::get);
         if let Some(c) = c {
@@ -85,6 +87,7 @@ extern "C" fn start() -> ! {
 
 #[panic_handler]
 fn on_panic(info: &PanicInfo) -> ! {
+    // print panic info and hang
     println!("{}", info);
 
     loop {}