From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D70C7C433E0 for ; Wed, 13 Jan 2021 13:46:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8EE7C23370 for ; Wed, 13 Jan 2021 13:46:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725902AbhAMNqA (ORCPT ); Wed, 13 Jan 2021 08:46:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:40214 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725747AbhAMNp7 (ORCPT ); Wed, 13 Jan 2021 08:45:59 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 18F84235F9 for ; Wed, 13 Jan 2021 13:45:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610545518; bh=RtlaE9J65v12+J/6lbmgii2+Y3BY+wZws9oPMNRLbyw=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=bwt77kQzi3TUQ3xGOdoqZYt9J0R1/7yQGCsTaMsjG1QPB/92EMmML2cJWqV4aaSt9 VMAGoQAI9Yel8nl0qw+QsfGHPyc0/HGPEzpWrqlZZ5jDB3q5Ot7nra8AGCNI7snRHm bWgHbs1Gg5jY5tFXkRkE+9pLjB70VIR8DDTcsPhcr03gFUTVSKMAzInXlJMajmwg1a X8gFWnCK3dJ4l0IU2/8wsqzOFUW+kjZsoJyRA24/1bkwejXH7vmS45kMgB3GjMrtZM LlWtOmk0m/TDxaGdZGxQLp0cZyxgCSn6gviV6rAXxCQxSHkfPBRb3kOXu8vdwBcxjV rRK5agVcZgbdA== Received: by mail-ot1-f48.google.com with SMTP id w3so1869462otp.13 for ; Wed, 13 Jan 2021 05:45:17 -0800 (PST) X-Gm-Message-State: AOAM532iWxkOIiFVvKbSvzF5KzQmbH5HSJenblTK8/WWRNpnJ6W2f3jk Dsscxacr4Ns36vsaN4PnFvF9uFQYzLGNjiFGifg= X-Google-Smtp-Source: ABdhPJx2v6CKPuAGtI2BQ/naF3Kn3i6GYnzkXFTxcVDUbUl5u9LFkg7OLK4TAHz1wQBhfS+590IiFSovP/PAJvXkK9w= X-Received: by 2002:a9d:7a4b:: with SMTP id z11mr1247229otm.305.1610545517013; Wed, 13 Jan 2021 05:45:17 -0800 (PST) MIME-Version: 1.0 References: <20210109055645.GA2009@1wt.eu> <6fb7e3f5035d44fab9801001f1811b59@AcuMS.aculab.com> In-Reply-To: From: Arnd Bergmann Date: Wed, 13 Jan 2021 14:44:59 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Old platforms: bring out your dead To: Linus Walleij Cc: Andy Shevchenko , William Breathitt Gray , David Laight , Willy Tarreau , Linux ARM , Linux Kernel Mailing List , Krzysztof Adamski , Oleksij Rempel , Baruch Siach , Russell King - ARM Linux , Daniel Tang , =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= , Jamie Iles , Barry Song , Viresh Kumar , Jonas Jensen , Marc Gonzalez , Hartley Sweeten , Lubomir Rintel , Neil Armstrong , Shawn Guo , Alex Elder , Alexander Shiyan , Koen Vandeputte , Hans Ulli Kroll , Vladimir Zapolskiy , Wei Xu , Steven Rostedt , Yoshinori Sato , Mark Salter , Michael Ellerman , Geert Uytterhoeven , Thomas Bogendoerfer Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 13, 2021 at 1:02 PM Linus Walleij wrote: > On Wed, Jan 13, 2021 at 11:27 AM Andy Shevchenko wrote: > > On Mon, Jan 11, 2021 at 11:55 AM David Laight wrote: > > > basically 486 but have a few extra instructions - probably just cpuid > > > and (IIRC) rdtsc. > > > Designed for low power embedded use they won't ever have been suitable > > > for a desktop - but are probably fast enough for some uses. > > > I'm not sure how much keeping 486 support actually costs, 386 was a > > > PITA - but the 486 fixed most of those issues. > > > > Right, we have "last of mohicans" (to date) Intel Quark family of CPUs > > (486 core + few i586 features). > > This is for the embedded world and probably not for powerful use. > > What is the status of PC/104? > https://en.wikipedia.org/wiki/PC/104 > > I have three GPIO drivers for PC/104 machines and these are for > embedded industrial usecases. I am curious about what CPUs these > beasts run on in practice? Are they getting upgraded? I had a look at those earlier when trying to find out what the remaining users of CONFIG_ISA are. It turns out that you can still easily get new x86 hardware with PC/104+ (combined ISA and PCI, not PCIe) connectors, see e.g. https://www.versalogic.com/product/SandCat/. Like the older VMEbus based systems, these would have at least 10 years of hardware availability (sometimes much more) and are indeed designed for use over decades after that. On the other hand, the set of ISA-style peripherals that you would connect here has little overlap with the those you'd find on a 1990's PC or Unix workstation, and I would expect that a lot of device drivers for them were never submitted for mainline because they are application specific. We have a couple of ARMv5-generation systems with PC/104 support, added before the start of the git history: * s3c2410/bast * s3c2410/vr1000 * pxa25x/viper * pxa27x/zeus I would assume that some of those are still operational somewhere in the world (along with similar machines without mainline support), but none have seen in field kernel updates for years. There is also ep93xx/ts72xx, which has a PC/104 connector but no Linux support for it. A new version of the board was added in 2017, so there are clearly still users, but they would need add-on patches to use PC/104. Arnd