Initial Setup for the microbit v1

examples/overflow.rs

@@ -0,0 +1,28 @@
+#![no_main]
+#![no_std]
+
+use template_microbit as _; // global logger + panicking-behavior + memory layout
+
+#[cortex_m_rt::entry]
+fn main() -> ! {
+    ack(10, 10);
+    template_microbit::exit()
+}
+
+fn ack(m: u32, n: u32) -> u32 {
+    // waste stack space to trigger a stack overflow
+    let mut buffer = [0u8; 16 * 1024];
+    // estimate of the Stack Pointer register
+    let sp = buffer.as_mut_ptr();
+    defmt::println!("ack(m={=u32}, n={=u32}, SP={:x})", m, n, sp);
+
+    if m == 0 {
+        n + 1
+    } else {
+        if n == 0 {
+            ack(m - 1, 1)
+        } else {
+            ack(m - 1, ack(m, n - 1))
+        }
+    }
+}