Re: Eurotech/SphereII port of NetBSD5/evbarm

[Raphael Langerhorst <raphael%netpark.at@localhost>]

Am Montag, 22. Juni 2009 15:12:14 schrieben Sie:
> > I've been working on porting NetBSD 5.0 to the Eurotech/SphereII
> > board, which uses a Cirrus Logic EP9315 ARM920TDMI processor: [...]
> >
> > [...] the same results - that only the first 17 characters are
> > printed to console and then userland does not continue.
>
> Userland does not continue, or userland does not produce any further
> output?  There's a critical difference between the two, and it's easy
> to confuse them.
>
> My furst guess would be that the problem is in the serial driver when
> running off interrupts (as opposed to polled-mode console output), and
> it's got a 16- or 17-byte FIFO: output gets stuffed into the FIFO until
> it's full, but the interrupt that would normally provoke reloading more
> data when the FIFO drains isn't working right.  If this guess is right,
> the rest of the data is in the output queue and will get prinetd if
> something calls the interrupt handler.

Yes, this was the issue!

I've checked the serial driver and noticed that I had mindlessly commented out 
the interrupt routine as it seemed to me it was only turning on and off the 
leds. However, there was a very important line:

n = epcomintr(arg);

which was never called of course. I have reeanbled the interrupt and now 
everything works.

Many thanks for this excellent hint, since I had already forgotton about this 
change I would never have thought of it.

I've updated the website with the fixed port.

Raphael