Fix logging levels in scheduler (#635)

crates/scheduler/CHANGELOG.md

@@ -8,6 +8,7 @@
 
 ### Minor
 
+- Trap applets calling into host during init (except for debug printing)
 - Support `PlatformLock` protocol call
 - Support `AppletExitStatus` protocol call (the platform keeps running when the applet exits)
 - Support `Applet{Install,Uninstall}` protocol calls
@@ -16,6 +17,7 @@
 
 ### Patch
 
+- Reduce logging level of applet trapping (those are not errors)
 - Make sure at compile-time that exactly one `native` or `wasm` feature is enabled
 - Use `derive-where` instead of `derivative`
 - Implement `defmt::Format` for `Key` when `defmt` is enabled

crates/scheduler/src/lib.rs

@@ -362,7 +362,10 @@ impl<B: Board> Scheduler<B> {
         while let Some(call) = self.applet.get().unwrap().store_mut().last_call() {
             match self.host_funcs[call.index()].descriptor().name {
                 "dp" => (),
-                x => log::panic!("init called {} into host", log::Debug2Format(&x)),
+                x => {
+                    log::warn!("init called {} into host", log::Debug2Format(&x));
+                    return Ok(applet_trapped(self, Some(x)));
+                }
             }
             self.process_applet();
         }
@@ -493,10 +496,10 @@ impl<B: Board> Scheduler<B> {
 
 fn applet_trapped<B: Board>(scheduler: &mut Scheduler<B>, reason: Option<&'static str>) {
     match reason {
-        None => log::error!("Applet trapped in wasm (think segfault)."),
-        Some("sa") => log::error!("Applet aborted (probably a panic)."),
-        Some("se") => log::warn!("Applet exited."),
-        Some(name) => log::error!("Applet trapped calling host {:?}.", name),
+        None => log::warn!("Applet trapped in wasm (think segfault)."),
+        Some("sa") => log::warn!("Applet aborted (probably a panic)."),
+        Some("se") => log::info!("Applet exited."),
+        Some(name) => log::warn!("Applet trapped calling host {:?}.", name),
     }
     scheduler.stop_applet(match reason {
         Some("se") => ExitStatus::Exit,