From owner-freebsd-arch Thu May 25 11:15:43 2000 Delivered-To: freebsd-arch@freebsd.org Received: from rover.village.org (rover.village.org [204.144.255.49]) by hub.freebsd.org (Postfix) with ESMTP id F14F837B5A0 for ; Thu, 25 May 2000 11:15:35 -0700 (PDT) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (harmony.village.org [10.0.0.6]) by rover.village.org (8.9.3/8.9.3) with ESMTP id MAA19845; Thu, 25 May 2000 12:15:34 -0600 (MDT) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (localhost.village.org [127.0.0.1]) by harmony.village.org (8.9.3/8.8.3) with ESMTP id MAA85600; Thu, 25 May 2000 12:14:22 -0600 (MDT) Message-Id: <200005251814.MAA85600@harmony.village.org> To: Peter Wemm Subject: Re: Preemptive kernel on older X86 hardware Cc: Chuck Paterson , arch@FreeBSD.ORG In-reply-to: Your message of "Thu, 25 May 2000 08:27:47 PDT." <20000525152747.AFBF21CE1@overcee.netplex.com.au> References: <20000525152747.AFBF21CE1@overcee.netplex.com.au> Date: Thu, 25 May 2000 12:14:22 -0600 From: Warner Losh Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <20000525152747.AFBF21CE1@overcee.netplex.com.au> Peter Wemm writes: : I would not have too much trouble with a proposal that a I386_CPU and : maybe I486_CPU becoming mutually exclusive with the 586+ stuff. ie: if you : will still be able to build a kernel specifically to run on a 486, but by : default it would not fly. I think this would be OK, so long as it buys us something. : I think 586+ is a convenient boundary because I am not aware of many 586's : that don't have PNPBIOS support, while 486's are mixed as they predate win95 : by a fair way. Yes. Lots of the SBCs in the embedded world still are 486 based due to their cheap cost, lower power consumption and low pin counts. I just took plastic off a new 486 133 (AMD 5x86 133) the other day which was made this year. It does have PNPBIOS support. : Aiming for a default fresh-install target (remember, 5.0 is 6-12 months : away) where we require minimum 586+ and PNPBIOS etc etc would simplify : things a fair bit.. In such a scenario it should still be possible to : build a kernel to specifically support an i486 on a non-PNP isa-only system : without PCI etc. I have a 486 still running and would hate to loose it for : sentimental reasons, but I do custom builds for it anyway. I strongly doubt : that there will be many *fresh* 486 installs, if any at all. But how does one upgrade then. These older machines typically do do freshinstalls to upgrade them. In the village we have a spare machine that we upgrade by doing a fresh install, then mutate it to be one of the other machines, then pull the trigger and take the old one down and put the new one in to do a rolling upgrade. Also, there will be many fresh installs onto the embedded hardware. I personally just do an installworld to make these machines, but other users might not be as sophisticated. : But that is changing the subject. :-) : : > I would have no problem saying SMP is only supported on Pentiums or : > newer. : : I don't think we support 486 SMP right now, but I could be wrong. I think that you are right... warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message