did not work out

.vscode/tasks.json

@@ -39,6 +39,18 @@
                 "$rustc"
             ]
         },
+        {
+            "label": "xargo build --release --example nested_noread",
+            "type": "shell",
+            "command": "xargo build --features \"wcet_bkpt\" --example nested_noread",
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "problemMatcher": [
+                "$rustc"
+            ]
+        },
         {
             "label": "xargo build --release --example nested --features wcet_bkpt",
             "type": "shell",

examples/nested.rs

@@ -122,11 +122,13 @@ fn exti0(
     rtfm::bkpt();
 }
 
+#[inline(never)]
 fn exti1(_t: &mut Threshold, _r: EXTI1::Resources) {
     // C, J
     rtfm::bkpt();
 }
 
+#[inline(never)]
 fn exti2(_t: &mut Threshold, _r: EXTI2::Resources) {
     // E, H
     rtfm::bkpt();

macros/src/trans.rs

@@ -427,6 +427,27 @@ fn resources(app: &App, ownerships: &Ownerships, root: &mut Vec<Tokens>) {
                                 )
                             }
                         }
+
+                        fn claim_mut_noread<R, F>(
+                            &mut self,
+                            t: &mut #krate::Threshold,
+                            f: F,
+                        ) -> R
+                        where
+                            F: FnOnce(
+                                &mut #krate::Static<#ty>,
+                                &mut #krate::Threshold) -> R
+                        {
+                            unsafe {
+                                #krate::claim_noread(
+                                    #krate::Static::ref_mut(&mut #res_rvalue),
+                                    #ceiling,
+                                    #device::NVIC_PRIO_BITS,
+                                    t,
+                                    f,
+                                )
+                            }
+                        }
                     });
                 } else {
                     impl_items.push(quote! {
@@ -501,6 +522,30 @@ fn resources(app: &App, ownerships: &Ownerships, root: &mut Vec<Tokens>) {
                                 )
                             }
                         }
+
+    thueothueoa
+                        fn claim_mut_noread<R, F>(
+                            &mut self,
+                            t: &mut #krate::Threshold,
+                            f: F,
+                        ) -> R
+                        where
+                            F: FnOnce(
+                                &mut #krate::Static<#device::#name>,
+                                &mut #krate::Threshold) -> R
+                        {
+                            unsafe {
+                                #krate::claim_noread(
+                                    #krate::Static::ref_mut(
+                                        &mut *#device::#name.get(),
+                                    ),
+                                    #ceiling,
+                                    #device::NVIC_PRIO_BITS,
+                                    t,
+                                    f,
+                                )
+                            }
+                        }
                     });
                 }
 

src/lib.rs

@@ -142,9 +142,50 @@ where
                     basepri::write(hw);
                     if cfg!(feature = "wcet_bkpt") {bkpt();} else {nop();}
 
+                    let ret = f(data, &mut Threshold::new(ceiling));
+                    
+                    if cfg!(feature = "wcet_bkpt") {bkpt();} else {nop();}
+                    basepri::write(old);
+                    ret
+                }
+            }
+        }
+    } else {
+        f(data, t)
+    }
+}
+
+#[inline]
+#[doc(hidden)]
+pub unsafe fn claim_noread<T, R, F>(
+    data: T,
+    ceiling: u8,
+    _nvic_prio_bits: u8,
+    t: &mut Threshold,
+    f: F,
+) -> R
+where
+    F: FnOnce(T, &mut Threshold) -> R,
+{
+    if ceiling > t.value() {
+        match () {
+            #[cfg(armv6m)]
+            () => atomic(t, |t| f(data, t)),
 
+            #[cfg(not(armv6m))]
+            () => {
+                let max_priority = 1 << _nvic_prio_bits;
+
+                if ceiling == max_priority {
+                    atomic(t, |t| f(data, t))
+                } else {
+                    //let old = basepri::read();
+                    let hw = (max_priority - ceiling) << (8 - _nvic_prio_bits);
+                    basepri::write(hw);
+                    if cfg!(feature = "wcet_bkpt") {bkpt();} else {nop();}
                     let ret = f(data, &mut Threshold::new(ceiling));
                     if cfg!(feature = "wcet_bkpt") {bkpt();} else {nop();}
+                    let old = (max_priority - t.value()) << (8 - _nvic_prio_bits);
                     basepri::write(old);
                     ret
                 }