Subject: Re: HW question & sbic sync patch
To: Niklas Hallqvist <niklas@appli.se>
From: Michael L. Hitch <osymh@gemini.oscs.montana.edu>
List: amiga-dev
Date: 08/19/1994 08:47:48
On Aug 19, 5:25am, Niklas Hallqvist wrote:
> First of all, I have a question on how to best handle an amiga
> hardware problem: On the A2000 the Z2 space will get cached by
> the CPU from what I've heard. Now if one have volatile registers
Not quite - the only Z2 space that is cached is Z2 memory. Any
non-memory devices that autoconfigure into the Z2 memory area are
not going to be in the Memlist structures. And since they are not
in the Z2 I/O expansion area, they will never be mapped at all by
the kernel. It will require modification to amiga_init.c and the
configuration routines to be able to handle this.
> How about cachectl? Is it an expensive operation to toggle
Cachectl only deals with pushing the data cache and invalidating
the caches. Enabling/disabling the cache done by manipulating the
CACR to control whether caching is enabled or not, or by manipulating
the cache control bit(s) in the MMU pages for a finer control (at a
page leve).
Michael
--
Michael L. Hitch INTERNET: osymh@montana.edu
Computer Consultant
Office of Systems and Computing Services
Montana State University Bozeman, MT USA
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