Subject: Re: IEEE1275 OpenBoot support?
To: Theo de Raadt <firstname.lastname@example.org>
From: Andrew Cagney <email@example.com>
Date: 12/12/1994 18:32:01
Excerpts from mail: 11-Dec-94 Re: IEEE1275 OpenBoot suppo.. Theo de
> > I think of OpenBoot (among other things) as a mechanism that allows a
> > kernel to access a device in the absence of a native device driver
> > (perhaphs I'm wrong). When looking at devices for a new target, going
> > down the path of implemting the open boot interface (assuming the rest
> > was there) would be easier then initially worrying about native devices.
> As far as I know that isn't the case, because it probably doesn't take
> interrupts into account. I believe the Sparc OpenBOOT device drivers
> are all polled.
I believe your right about the drivers using polling. Regarding
interrupts, I'm uncertain, I do know that (in at least one case) the
driver must handle exceptions (I'll check when I get home).
Any way, to me, a kernel that boots using a slow polling device driver
is better then the kernel not booting at all.
more later, Andrew