Function register_bottom_half_handler_l2 

pub fn register_bottom_half_handler_l2(func: fn(u8))

Registers a bottom half callback to be executed at interrupt level 2.

Unlike the level 1 bottom half callback, the level 2 bottom half callback registered with this function cannot re-enable local IRQs. The function takes the IRQ number being processed as argument.

The function may be called only once; subsequent calls take no effect.