uart: impl fmt::Write

src/main.rs

@@ -4,6 +4,8 @@
 //[feature(global_asm)]
 #![feature(naked_functions)]
 
+use core::fmt::Write;
+
 use panic_abort as _;
 use r0::zero_bss;
 
@@ -44,8 +46,6 @@ pub unsafe extern "C" fn _boot_cores() -> ! {
 }
 
 fn main() {
-    let uart = Uart::uart0();
-    for b in "Hello World\r\n".bytes() {
-        uart.write_byte(b);
-    }
+    let mut uart = Uart::uart0();
+    writeln!(uart, "Hello World\r").unwrap();
 }

src/uart/mod.rs

@@ -1,5 +1,7 @@
 #![allow(unused)]
 
+use core::fmt;
+
 mod regs;
 pub use regs::RegisterBlock;
 
@@ -32,3 +34,12 @@ impl Uart {
         self.regs.write_byte(v);
     }
 }
+
+impl fmt::Write for Uart {
+    fn write_str(&mut self, s: &str) -> Result<(), fmt::Error> {
+        for b in s.bytes() {
+            self.write_byte(b);
+        }
+        Ok(())
+    }
+}