shilga[m]: > <@shilga:matrix.org> Hi,
> I'm again searching for some advise where I would be thankful to get some input.
> 
> I having a special usecase there the embedded device is used in two phases. In the first phase only one core is running and two SPI devices are used (one is an sd card), they are on the same bus. (Using `RefCellDevice`). After this first phase core 0 is not using any SPI at all, but the sd card needs to be used further on core 1. I can't manage to share the sd card with core 1 because, `RefCellDevice` does rightfully not implement `send`. But I don't know how else this should be done. I fairly new to Rust, I'm completely lost here. I don't know how the goal can be achieved. How can I tell the compiler, to move the whole SPI bus to the second core and that this is fine, because the first core is not using it at all after the first phase?

If you're using embassy, drivers can be made with an `&mut` of a peripheral, which makes them easier to "tear down", so that after the first phase you can pass the peripheral by ownership to the second core