Add RTT console

src/devices/console.rs

@@ -22,8 +22,9 @@
  * SOFTWARE.
  */
 
+use crate::jlink_rtt::Output as JLinkOutput;
 use crate::platform;
-use core::fmt;
+use core::fmt::{self, Write};
 
 /// A trait that must be implemented by devices that are candidates for the
 /// global console.
@@ -49,6 +50,7 @@ pub enum Output {
     None(NullConsole),
     MiniUart(platform::MiniUart),
     PL011Uart(platform::PL011Uart),
+    RTT(JLinkOutput),
 }
 
 impl From<platform::MiniUart> for Output {
@@ -63,6 +65,12 @@ impl From<platform::PL011Uart> for Output {
     }
 }
 
+impl From<JLinkOutput> for Output {
+    fn from(instance: JLinkOutput) -> Self {
+        Output::RTT(instance)
+    }
+}
+
 pub struct Console {
     output: Output,
 }
@@ -80,6 +88,7 @@ impl Console {
             Output::None(i) => i,
             Output::MiniUart(i) => i,
             Output::PL011Uart(i) => i,
+            Output::RTT(i) => i,
         }
     }
 

src/jlink_rtt.rs

@@ -216,11 +216,28 @@ impl Output {
     }
 }
 
-impl fmt::Write for Output {
+impl Drop for Output {
-    fn write_str(&mut self, s: &str) -> fmt::Result {
+    fn drop(&mut self) {}
+}
+
+impl crate::devices::ConsoleOps for Output {
+    fn puts(&self, s: &str) {
         unsafe {
             _SEGGER_RTT.up.write(s.as_bytes(), true);
         }
+    }
+
+    fn putc(&self, c: char) {
+        let mut buf = [0u8; 4];
+        let s = c.encode_utf8(&mut buf);
+        self.puts(s);
+    }
+}
+
+impl fmt::Write for Output {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        use crate::devices::console::ConsoleOps;
+        self.puts(s);
         Ok(())
     }
 }

src/main.rs

@@ -83,6 +83,9 @@ fn kmain() -> ! {
     // }
 
     // jtag_dbg_wait();
+    CONSOLE.lock(|c| {
+        c.replace_with(Output::new().into());
+    });
 
     let mut out = Output::new();
     writeln!(out, "JLink RTT is working!"); // @todo RttConsole