stuff

lib/src/rtt.rs

@@ -0,0 +1,42 @@
+use core::cell::RefCell;
+
+use critical_section::Mutex;
+use rtt_target::{rtt_init, UpChannel};
+
+pub type RttWriteFn = fn(&[u8]);
+
+static CHANNEL: Mutex<RefCell<Option<UpChannel>>> = Mutex::new(RefCell::new(None));
+
+/// Write directly to the rtt output. Must call [init_rtt_logger] first.
+pub fn rtt_write(bytes: &[u8]) {
+    critical_section::with(|cs| {
+        let mut slot = CHANNEL.borrow_ref_mut(cs);
+        if let Some(channel) = slot.as_mut() {
+            channel.write(bytes);
+        };
+    });
+}
+
+pub fn init_rtt_logger() -> RttWriteFn {
+    let channels = rtt_init! {
+        up: {
+            0: {
+                size: 1024
+                mode: NoBlockSkip
+                name: "Terminal"
+            }
+        }
+    };
+
+    critical_section::with(|cs| {
+        let mut slot = CHANNEL.borrow_ref_mut(cs);
+
+        if slot.is_some() {
+            return rtt_write;
+        }
+
+        *slot = Some(channels.up.0);
+
+        rtt_write
+    })
+}