spawn POC works, likely unsound

examples/spawn.rs

@@ -0,0 +1,33 @@
+//! examples/message.rs
+
+#![deny(unsafe_code)]
+// #![deny(warnings)]
+#![no_main]
+#![no_std]
+
+use cortex_m_semihosting::{debug, hprintln};
+use panic_semihosting as _;
+
+#[rtic::app(device = lm3s6965)]
+mod app {
+    #[init(spawn = [foo])]
+    fn init(_c: init::Context) {
+        foo::spawn(1, 2).unwrap();
+    }
+
+    #[task()]
+    fn foo(_c: foo::Context, x: i32, y: u32) {
+        hprintln!("foo {}, {}", x, y).unwrap();
+        if x == 2 {
+            debug::exit(debug::EXIT_SUCCESS);
+        }
+        foo::spawn(2, 3).unwrap();
+    }
+
+    // RTIC requires that unused interrupts are declared in an extern block when
+    // using software tasks; these free interrupts will be used to dispatch the
+    // software tasks.
+    extern "C" {
+        fn SSI0();
+    }
+}