Add an on-device test suite

testsuite/tests/test.rs

@@ -0,0 +1,12 @@
+#![no_std]
+#![no_main]
+
+use cortex_m_rt::entry;
+use {{project-name}} as _; // memory layout + panic handler
+
+#[entry]
+fn main() -> ! {
+    assert!(false, "TODO: Write actual tests");
+
+    {{project-name}}::exit();
+}