> > > Is there a reason to set the counter to 0xfff0 instead of 0xffff ?
> > 
> > Giving serial console some time to push out FIFOs. But yeah, it is an
> > arbitrary value.
> 
> 16 cycles as 32.768 kHz would be 488µs. Assuming a 115200 serial baud rate 
> that would allow transmission of a bit less than 6 characters. I wonder if 
> it's worth it. Shouldn't the restart core code instead flush the serial FIFOs 
> explicitly before calling the restart handler if that behaviour is desired ?

It should, but I didn't check yet. I wanted to when going from RFC to PATCH.