Convert \n to \r\n on serial output

src/interrupts.rs

@@ -244,7 +244,11 @@ extern "C" fn syscall_handler() {
     match regs.rax {
         0 => {
             let rval = if let Some(chr) = char::from_u32(regs.rcx.wrapping_cast()) {
+                if chr == '\n' {
+                    print!("\r\n");
+                } else {
                     print!("{}", chr);
+                }
                 0
             } else {
                 1

src/serial.rs

@@ -50,10 +50,10 @@ macro_rules! print {
 
 #[macro_export]
 macro_rules! println {
-    () => ($crate::print!("\n"));
+    () => ($crate::print!("\r\n"));
     ($($arg:tt)*) => ({
         $crate::serial::_print(format_args!($($arg)*));
-        $crate::print!("\n");
+        $crate::print!("\r\n");
     })
 }