rp/bootsel: add test.

tests/rp/src/bin/bootsel.rs

@@ -0,0 +1,26 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+teleprobe_meta::target!(b"rpi-pico");
+
+use defmt::{assert_eq, *};
+use embassy_executor::Spawner;
+use embassy_time::{Duration, Timer};
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut p = embassy_rp::init(Default::default());
+    info!("Hello World!");
+
+    // add some delay to give an attached debug probe time to parse the
+    // defmt RTT header. Reading that header might touch flash memory, which
+    // interferes with flash write operations.
+    // https://github.com/knurling-rs/defmt/pull/683
+    Timer::after(Duration::from_millis(10)).await;
+
+    assert_eq!(p.BOOTSEL.is_pressed(), false);
+
+    info!("Test OK");
+    cortex_m::asm::bkpt();
+}