Why isn’t it possible to pass data between a coroutine and a task? Perhaps using a queue?
Also, even regarding that there is a reason for it that I do not yet understand, why wouldn’t we be able to use the ISR routines from the CoRoutines? The only obstacle is that any called function may not block (because of the shared stack), but the ISR funcitons never block, so they could theoretically be used from the coroutine environment.
And my other solution would be to define an svc (on cortex-m3 for example) to do the queueing. SVC 0 is used for task switching, but in my opinion I could use another SVC to do the queue up work. In this case the queueing would happen from isr environment, so the Queue_ISR functions could be used. Some adjustment must be made to the ported code, so that the SVC handler extracts the svc code, and depending on the svc number queues or switches tasks. Do you think this could work?