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From: Alexey Pialkin <pialkin@abel.pdmi.ras.ru>
Message-Id: <199609201110.PAA19509@abel.pdmi.ras.ru>
Subject: Re: New doscmd available for testing/munching
To: sos@freebsd.org
Date: Fri, 20 Sep 1996 15:10:43 +0400 (MSD)
Cc: msmith@atrad.adelaide.edu.au, j_mini@efn.org, emulation@freebsd.org
In-Reply-To: <199609201045.MAA03725@ra.dkuug.dk> from "sos@freebsd.org" at Sep 20, 96 12:45:35 pm
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> > > My 'conceptual model' for this went something like :
> > > 
> > > - allocate 128K in the emulation process for screen memory.
> > > - when vt is activated, copy the area that falls under the physical screen
> > >   memory to a temporary store.
> > > - mmap the screen memory onto your emulation's buffer.
> > > - copy your temporary store back.
> > > - when vt is deactivated, reverse the process.
> > 
> > Great.. The most funny thing that i am trying to do the same thing :( And no
> > result.. BTW problem is with mmap the screen memory onto emulation buffer ..
> > Somthing wrong there .. But what ?
> 
> What I meant was that I don't think that we can do a mmap onto memory
> thats is mapped directly to HW adressees, ask Dyson about this, he
> will know how to if at all possible. There is nothing syscons has
> to do with this, its strictly a vm problem...

Sorry me - but what do you mean by directly HW access ? In all cases before
using the direct access to 0xA0000-0xC0000 i must mmap() some part of /dev/mem
for that....

> > > ... but I really don't know what happens when you mmap() screen memory
> > > onto a section of your process' space that is already mapped.  Or would
> > 
> 
> As I said ask Dyson, I'n not sure this works at all in the curretn VM system...

Thanx, for nice advise..... Letter is written.

Alexey Pialkin