Date: Fri, 20 Sep 1996 14:33:46 +0400 (MSD) From: Alexey Pialkin <pialkin@abel.pdmi.ras.ru> To: msmith@atrad.adelaide.edu.au (Michael Smith) Cc: sos@freebsd.org, j_mini@efn.org, msmith@atrad.adelaide.edu.au, emulation@freebsd.org Subject: Re: New doscmd available for testing/munching Message-ID: <199609201033.OAA19193@abel.pdmi.ras.ru> In-Reply-To: <199609201011.TAA14497@genesis.atrad.adelaide.edu.au> from "Michael Smith" at Sep 20, 96 07:41:14 pm
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> sos@freebsd.org stands accused of saying: > > > > > > The problem is not with just screen mapping for drawing something(open > > > screen memory for drawing is simple just mmap some part of /dev/mem & viola ...) > > > My problem is that i am unabl to properly map some shadow screen for 0xA0000-0xB0000 address.... It's highly needable for programs working with screen background.. > > > > Hmm, I'm not sure we can do that, try ask John Dyson about that, he > > is out "mastermind" in vm stuff... > > 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 ? > ... 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 The only one thing i know :) - mmap() doesn't return any error. And mmaping porion of /dev/mem works fine. > you swap between a mapping to screen memory and a file? Or could you > map to _both_ screen memory and a file...? What do you mean by file ? The only one way is to map something is to play with files.. So all works with emulator buffer will begin from file. Or am i wrong ? Alexey Pialkin
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