From owner-freebsd-arch@FreeBSD.ORG Wed Nov 19 00:36:46 2014 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 07C9AA24; Wed, 19 Nov 2014 00:36:46 +0000 (UTC) Received: from h2.funkthat.com (gate2.funkthat.com [208.87.223.18]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "funkthat.com", Issuer "funkthat.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id C1B74C0E; Wed, 19 Nov 2014 00:36:45 +0000 (UTC) Received: from h2.funkthat.com (localhost [127.0.0.1]) by h2.funkthat.com (8.14.3/8.14.3) with ESMTP id sAJ0aWPr068634 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 18 Nov 2014 16:36:33 -0800 (PST) (envelope-from jmg@h2.funkthat.com) Received: (from jmg@localhost) by h2.funkthat.com (8.14.3/8.14.3/Submit) id sAJ0aWPt068633; Tue, 18 Nov 2014 16:36:32 -0800 (PST) (envelope-from jmg) Date: Tue, 18 Nov 2014 16:36:32 -0800 From: John-Mark Gurney To: Slawa Olhovchenkov Subject: Re: kernel linker: Overriding a driver shipped with kernel via module? Message-ID: <20141119003632.GN24601@funkthat.com> Mail-Followup-To: Slawa Olhovchenkov , d@delphij.net, "weh@microsoft.com >> Wei Hu" , kyliel@microsoft.com, huishao@microsoft.com, "Jun Fang (Wicresoft)" , "freebsd-arch@FreeBSD.org Arch" , re References: <546A8191.3090208@delphij.net> <20141118124544.GA95731@zxy.spb.ru> <20141119001510.GM24601@funkthat.com> <20141119002718.GP9763@zxy.spb.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141119002718.GP9763@zxy.spb.ru> User-Agent: Mutt/1.4.2.3i X-Operating-System: FreeBSD 7.2-RELEASE i386 X-PGP-Fingerprint: 54BA 873B 6515 3F10 9E88 9322 9CB1 8F74 6D3F A396 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html X-TipJar: bitcoin:13Qmb6AeTgQecazTWph4XasEsP7nGRbAPE X-to-the-FBI-CIA-and-NSA: HI! HOW YA DOIN? can i haz chizburger? X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.2 (h2.funkthat.com [127.0.0.1]); Tue, 18 Nov 2014 16:36:33 -0800 (PST) Cc: "weh@microsoft.com >> Wei Hu" , kyliel@microsoft.com, huishao@microsoft.com, "Jun Fang \(Wicresoft\)" , re , "freebsd-arch@FreeBSD.org Arch" , d@delphij.net X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Nov 2014 00:36:46 -0000 Slawa Olhovchenkov wrote this message on Wed, Nov 19, 2014 at 04:27 +0400: > On Tue, Nov 18, 2014 at 04:15:10PM -0800, John-Mark Gurney wrote: > > > Slawa Olhovchenkov wrote this message on Tue, Nov 18, 2014 at 16:45 +0400: > > > On Mon, Nov 17, 2014 at 03:15:29PM -0800, Xin Li wrote: > > > > > > > Right now one can declare version for a module by doing something like: > > > > > > > > MODULE_VERSION(module_name, module_version); > > > > > > > > Sometimes, it may be desirable for a vendor to release a new driver > > > > that overrides the driver shipped with the kernel itself. However, it > > > > seems that the MODULE_VERSION facility would just refuse the module > > > > when preloaded with kernel. > > > > > > > > Looking at some other vendor drivers, they are using a slightly > > > > different module name to overcome this limitation. Is that the only > > > > way to do it? > > > > > > I think now time to move to modulated kernel and load all drivers > > > currently present in GENERIC as modules (via loader.conf). > > > > This becomes slightly more difficult for storage drivers which must > > be loaded at boot time so the you can mount root from it... But yes, > > we are interested in methods to make it easier/more automatic for > > modules to be loaded to support the hardware that is present in a > > system... > > When loader can load kernel -- loader can load driver module, this is > not Linux (but yes, loader need plugable and stackable framework for > access FS -- currenly booting from ZFS over gstripe not allowed). That isn't the only issue.. another issue is identifing the correct kernel module(s) to load at boot... iirc, you cannot unload a kernel module loaded at boot time... -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."