Subject: Re: Things to work on
To: David Brownlee <abs@netbsd.org>
From: Richard Earnshaw <rearnsha@arm.com>
List: port-arm
Date: 05/24/2001 12:09:23
> On Thu, 24 May 2001, Richard Earnshaw wrote:
>
> > > Make it SMP safe (hard to test, but we should be in case someone ever does an
> > > SMP based arm box)
> >
> > Somewhat pointless at this time, particularly if it will impact
> > performance. Until the models for cache coherency on SMP ARM systems are
> > defined it isn't really sensible to consider this (IMO).
> >
> We may be able to obtain a bunch of hydra boards, complete with
> schematics and details of the changes to make them work with
> StrongARM CPUs. On a 16Mhz memory bus a fully loaded hydra is..
> uh, a decidedly mismatched beast, but for two or three CPUs it
> should give a boost.
Hmm, muses.... a hydra with 3 kinnetics... OK, so they wouldn't be very
symmetric.
>
> Do we have anywhere a brief document that gives an overview
> of what a NetBSD pmap should provide, how it should be structured
> to best handle various cache and MMU models, and specific areas
> to watch out for? (As opposed to the current method for various
> ports which is 'look at the latest i386 or alpha pmap' :)
In -current you can "man 9 pmap", other than that there is only "Design
and implementation of the BSD 4.4 OS", but that's getting away from NetBSD
these days since it doesn't cover UVM or all the other recent changes
(it's still good background though).