From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 23 Oct 2014 05:13:36 +0200 (CEST) Received: from resqmta-ch2-07v.sys.comcast.net ([69.252.207.39]:44909 "EHLO resqmta-ch2-07v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27011350AbaJWDNedqFXn (ORCPT ); Thu, 23 Oct 2014 05:13:34 +0200 Received: from resomta-ch2-13v.sys.comcast.net ([69.252.207.109]) by resqmta-ch2-07v.sys.comcast.net with comcast id 6TCv1p0032N9P4d01TDRul; Thu, 23 Oct 2014 03:13:25 +0000 Received: from [192.168.1.13] ([69.251.152.165]) by resomta-ch2-13v.sys.comcast.net with comcast id 6TDN1p00B3aNLgd01TDNlw; Thu, 23 Oct 2014 03:13:25 +0000 Message-ID: <54487246.605@gentoo.org> Date: Wed, 22 Oct 2014 23:13:10 -0400 From: Joshua Kinard User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: linux-mips@linux-mips.org Subject: Re: Single MIPS kernel References: <20141022083437.GB18581@linux-mips.org> <5447F155.60106@gmail.com> <20141022192018.GD12502@linux-mips.org> <1414016140.5994.9.camel@decadent.org.uk> <20141022232233.GF12502@linux-mips.org> <1414026131.5994.20.camel@decadent.org.uk> In-Reply-To: <1414026131.5994.20.camel@decadent.org.uk> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20140121; t=1414034005; bh=dVIYJRXn7eiW+jsBgNbqt9nFy8K7zRkPdOVpqHWoSQ4=; h=Received:Received:Message-ID:Date:From:MIME-Version:To:Subject: Content-Type; b=MMFGbOfdKhcZ2Phcy2rNZpXnoSwkLV9Ewh+fIAF6s7PPmBM8YXGY8AUTa1F2neUtv Vgwgy6lR5+Zz4T5fDrNqXknte1FI2hA63wt6zGLWP7lleXGlEKrn5BDSMHAJ7UG7eN iXOe1ssYC3hpgsPwAG845kwDitRErxOAfClgATSwdYzskeSaOFFHrykpsXHfkepnFp CXoRC7NojzuxE82mCj/JNzExlgLaX4NzOsFcWi5IvMG8RV10TgScYmUdWVT2QNy3ZE Yb4Sx/2Vef64MOj0O4ZgZJK0EMsKAARBkk+HOl0IxIj3gcD5gOUNaikgiahGhg5rSk UXWUv2JNiyWQQ== Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 43516 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: kumba@gentoo.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 10/22/2014 21:02, Ben Hutchings wrote: > On Thu, 2014-10-23 at 01:22 +0200, Ralf Baechle wrote: >> On Wed, Oct 22, 2014 at 11:15:40PM +0100, Ben Hutchings wrote: >> >>>> >>>> That's probably more of an implementation detail. I'm more concerned about >>>> the overall bloat. I think many embedded users are so addivted to benchmark >>>> results that this going to make or break the whole scheme. >>> >>> If you can make relocation a configuration option (as on x86), it would >>> allow distributions to build multiplatform kernels without preventing >>> embedded users from building a kernel optimised for their specific >>> system. But I know very little about MIPS or how intrusive the changes >>> for relocation would have to be. Perhaps it would be too much of a >>> maintenance burden to make this an option. >> >> The scope of the changes is relativly limited - we're much more concerned >> about the impact on binary size, memory size or performance of the >> various approaches under discussion. >> >> I wonder kernels for which platforms would Debian want to unify? > > I don't have high expectations for being able to unify those we > currently support. Realistically, I expect that most development effort > will go into new platforms. (What we saw with ARM was that > multi-platform was implemented for most ARMv7 platforms (for which we > now need only 2 configurations) but only slowly for older chips (4 > configurations, and that's after dropping 2 platforms).) > > Anyway, we have one 32-bit configuration for each byte order > (4kc-malta), and the following 64-bit configurations: > > [big-endian] > r4k-ip22: CONFIG_SGI_IP22, CONFIG_CPU_R4X00 > r5k-ip32: CONFIG_SGI_IP32, CONFIG_CPU_R5000 As far as I know, IRIX includes kernels specific to each SGI system (IPxx), but it seems they're CPU agnostic. They are relocatable, though. Been awhile since I watched sash boot followed by an IRIX kernel, but it does 3-4 relocations before finally booting. So a relocatable MIPS kernel on the SGI platforms seems possible. Probably requires arcane knowledge of ARCS, though. Bootloader-wise, Stan's 'arcload' can handle booting multiple kernels across various SGI platforms. We used it on the Gentoo SGI LiveCD back in 2006 to create a single CD that could boot on IP22, IP27, IP30, & IP32, using different kernels for each system and CPU (I think there was one volume header slot left at the end for arcload itself). -- Joshua Kinard Gentoo/MIPS kumba@gentoo.org 4096R/D25D95E3 2011-03-28 "The past tempts us, the present confuses us, the future frightens us. And our lives slip away, moment by moment, lost in that vast, terrible in-between." --Emperor Turhan, Centauri Republic