turn into a Cargo crate

examples/itm.rs

@@ -0,0 +1,41 @@
+//! Sends "Hello, world!" through the ITM port 0
+//!
+//! **IMPORTANT** Not all Cortex-M chips support ITM. You'll have to connect the
+//! microcontroller's SWO pin to the SWD interface. Note that some development
+//! boards don't provide this option.
+//!
+//! ITM is much faster than semihosting. Like 4 orders of magnitude or so.
+//!
+//! You'll need [`itmdump`] to receive the message on the host plus you'll need
+//! to uncomment OpenOCD's ITM support in `.gdbinit`.
+//!
+//! [`itmdump`]: https://docs.rs/itm/0.1.1/itm/
+
+#![feature(used)]
+#![no_std]
+
+#[macro_use]
+extern crate cortex_m;
+extern crate cortex_m_rt;
+
+use cortex_m::{asm, interrupt, peripheral};
+
+fn main() {
+    interrupt::free(
+        |cs| {
+            let itm = peripheral::ITM.borrow(&cs);
+
+            iprintln!(&itm.stim[0], "Hello, world!");
+        },
+    );
+}
+
+// As we are not using interrupts, we just register a dummy catch all handler
+#[allow(dead_code)]
+#[used]
+#[link_section = ".rodata.interrupts"]
+static INTERRUPTS: [extern "C" fn(); 240] = [default_handler; 240];
+
+extern "C" fn default_handler() {
+    asm::bkpt();
+}