From mboxrd@z Thu Jan 1 00:00:00 1970 From: schmitz Subject: Re: [PATCH 0/4] Atari kernel-in-FastRAM patches, take three Date: Tue, 01 Apr 2014 20:45:36 +1300 Message-ID: <533A6EA0.9030808@biophys.uni-duesseldorf.de> References: <1396137686-32678-1-git-send-email-schmitz@debian.org> <8761mvl3jb.fsf@igel.home> <87a9c63x1c.fsf@igel.home> <87txae2dt4.fsf@igel.home> <20140331235216.GA2109@mail.biophys.uni-duesseldorf.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pb0-f43.google.com ([209.85.160.43]:43081 "EHLO mail-pb0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751497AbaDAHpp (ORCPT ); Tue, 1 Apr 2014 03:45:45 -0400 Received: by mail-pb0-f43.google.com with SMTP id um1so9460646pbc.30 for ; Tue, 01 Apr 2014 00:45:44 -0700 (PDT) In-Reply-To: Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: Geert Uytterhoeven Cc: Michael Schmitz , Andreas Schwab , Michael Schmitz , Linux/m68k , debian m68k Hi Geert, > >>>> do we know the size of the first memory chunk early enough in head.S? >>>> Maybe it's time to increase INIT_MAPPED_SIZE at least in cases where >>>> we know that there's more than 4 MB in the first memchunk ... >>>> >>> How do you know? You would have to reimplement the check paging_init >>> does. >>> >> I see - as a heuristic, we can probably assume that the first memchunk is >> the relevant one, and especially in the case of FastRAM, also the larger >> one. >> Does this hold for Amiga/Mac/VME as well? >> > > People want to run the kernel in the fastest memory chunk, which is typically > also the largest (slow Amiga mainboard memory may be 2 - 16 MiB for > Linux-capable machines, accelerator memory may be larger). > And the chunk the kernel runs from would always be the first chunk listed in bootinfo, since that's the one mapped at virtual address zero? > Don't know about Mac, but I have some memories of interleaved banks > and such... > Not sure I've ever seen accelerators or memory upgrades on the Macs that I hacked on. 4 MB was sort of plenty in those days. Cheers, Michael