Eliminate alloc::boxed::Box deps from Runtime

Author: j-devel

examples/xbd-net/src/embassy/executor.rs

@@ -1,27 +1,30 @@
-use mcu_if::{println, alloc::boxed::Box};
 use embassy_executor::{Spawner, raw::Executor as RawExecutor};
+use super::{to_raw, static_from_raw};
 
 // https://github.com/embassy-rs/embassy/blob/b6fc682117a41e8e63a9632e06da5a17f46d9ab0/embassy-executor/src/raw/mod.rs#L465
 #[export_name = "__pender"]
 fn pender(context: *mut ()) {
-    let signaler: &'static Signaler = unsafe { core::mem::transmute(context) };
-    if 0 == 1 { println!("@@ pender(): signaler: {:?}", signaler); }
+    //@@ let signaler: &'static Signaler = unsafe { core::mem::transmute(context) };
+    let signaler: &'static Signaler = static_from_raw(context);
+    if 0 == 1 { crate::println!("@@ pender(): signaler: {:?}", signaler); }
 }
 
 pub struct Executor {
     executor: RawExecutor,
-    _signaler: &'static Signaler, // c.f. embassy/embassy-executor/src/arch/std.rs
+    //@@ _signaler: &'static Signaler, // c.f. embassy/embassy-executor/src/arch/std.rs
+    _signaler: Signaler,
 }
 
 #[derive(Debug)]
 struct Signaler(()); // TODO
 
 impl Executor {
     pub fn new() -> Self {
-        let signaler = Box::leak(Box::new(Signaler(())));
+        //@@ let signaler = Box::leak(Box::new(Signaler(())));
+        let mut signaler = Signaler(());
 
         Self {
-            executor: RawExecutor::new(signaler as *mut _ as *mut ()),
+            executor: RawExecutor::new(to_raw(&mut signaler)),
             _signaler: signaler,
         }
     }

examples/xbd-net/src/embassy/mod.rs

@@ -1,4 +1,3 @@
-use mcu_if::alloc::boxed::Box;
 use super::xbd::{self, Xbd};
 
 mod executor;
@@ -30,19 +29,21 @@ async fn task_shell_stream() {
     xbd::process_shell_stream().await.unwrap();
 }
 
-pub struct Runtime(&'static mut Executor);
-
-impl Runtime {
-    pub fn new_static() -> Result<&'static mut Self, ()> {
-        Ok(Self::get_static(Self::new()))
-    }
+fn to_raw<T>(x: &mut T) -> *mut () { x as *mut _ as _ }
+fn static_from_raw<T>(p: *mut ()) -> &'static mut T { unsafe { core::mem::transmute(p) } }
+pub fn get_static<T>(x: &mut T) -> &'static mut T { static_from_raw(to_raw(x)) }
+/* deprecated
+pub fn get_static<T>(x: &mut T) -> &'static mut T {
+    use mcu_if::alloc::boxed::Box;
+    Box::leak(Box::new(x))
+}
+*/
 
-    fn new() -> Self {
-        Self(Self::get_static(Executor::new()))
-    }
+pub struct Runtime(Executor);
 
-    fn get_static<T>(x: T) -> &'static mut T {
-        Box::leak(Box::new(x))
+impl Runtime {
+    pub fn new() -> Self {
+        Self(Executor::new())
     }
 
     pub fn run(&'static mut self) -> ! {

examples/xbd-net/src/lib.rs

@@ -47,12 +47,15 @@ pub extern fn rustmod_start(
     if 0 == 1 { // debug
         Xbd::usleep(1_000_000);
         blogos12::test_misc();
-        return;
+        panic!("ok");
     }
 
     if 1 == 1 {
         println!("@@ [debug] `xbd_main()` with `embassy::Runtime` ...");
-        embassy::Runtime::new_static().unwrap().run();
+        embassy::get_static(&mut embassy::Runtime::new())
+            .run(); // -> !
+
+        // should be never reached
     } else {
         println!("@@ [debug] `xbd_main()` with `blogos12::Runtime` ...");
         let _ = blogos12::Runtime::new()