implement CRC write

flashloader/src/main.rs

@@ -52,6 +52,7 @@ static CLOCKS: OnceCell<Clocks> = OnceCell::new();
 #[rtic::app(device = pac, dispatchers = [U1, U2, U3])]
 mod app {
     use super::*;
+    use cortex_m::asm;
     use embedded_hal_nb::nb;
     use panic_rtt_target as _;
     use rtic::Mutex;
@@ -157,8 +158,9 @@ mod app {
     // `shared` cannot be accessed from this context
     #[idle]
     fn idle(_cx: idle::Context) -> ! {
-        #[allow(clippy::empty_loop)]
-        loop {}
+        loop {
+            asm::nop();
+        }
     }
 
     #[task(