From owner-freebsd-arm@freebsd.org Tue Oct 3 20:03:32 2017 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 650EEE230F4 for ; Tue, 3 Oct 2017 20:03:32 +0000 (UTC) (envelope-from lausts@acm.org) Received: from cdptpa-cmomta03.email.rr.com (cdptpa-outbound-snat.email.rr.com [107.14.166.227]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 3071B269D for ; Tue, 3 Oct 2017 20:03:31 +0000 (UTC) (envelope-from lausts@acm.org) Received: from mail.laus.org ([65.29.112.189]) by cmsmtp with ESMTP id zTPydjCFRZEW5zTQ0ddM6K; Tue, 03 Oct 2017 20:03:53 +0000 Received: from [192.168.1.100] (presario [192.168.1.100]) by mail.laus.org (8.15.2/8.15.2) with ESMTPS id v93K3Lra087029 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO) for ; Tue, 3 Oct 2017 16:03:21 -0400 (EDT) (envelope-from lausts@acm.org) X-Authentication-Warning: mail.laus.org: Host presario [192.168.1.100] claimed to be [192.168.1.100] Reply-To: lausts@acm.org Subject: Re: GENERIC kernel (was Re: BeagleBone Crochet Build Problem) To: freebsd-arm@freebsd.org References: <176dbdd5-1a32-06b2-7dd8-0647cc0fbe20@acm.org> <1506954050.22078.55.camel@freebsd.org> <1506962766.22078.69.camel@freebsd.org> <20171003170053.GB2918@lonesome.com> From: Thomas Laus Message-ID: <8eb57091-0b6f-3f0a-8c80-997b951a383f@acm.org> Date: Tue, 3 Oct 2017 16:03:21 -0400 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20171003170053.GB2918@lonesome.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-CMAE-Envelope: MS4wfO1+XuKuWodBuI916lOuBOMYciydI32QJI+LCHli17JMTVwRe4h3RPWCW1ufmyCFuIO9r4gSvX1E9xihUT3y1pYKz4lRt+aEhdWq+uMzhMCfAXP9DUXf z2PgE3o3R3mTa71r68TJmyUHMHN6K45mO7hJ4GBlXahvaGhBRx/i48Uw X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Oct 2017 20:03:32 -0000 On 10/03/17 13:00, Mark Linimon wrote: > On Mon, Oct 02, 2017 at 10:46:06AM -0600, Ian Lepore wrote: >> Why are we working towards a GENERIC kernel for arm? > > My intuition would be: > > - easier to tell new FreeBSD users how to start > - less work for Release Engineering to make targets > > OTOH I'm not doing the work so I don't get to set the > direction :-) > > My _opinion_ is that we still seem to have a steeper > curve for our new users than is necessary. I intend to > think about that more this fall. > That is probably 'wishful thinking' for the very distant future. Most of the common ARM SOC's have very different capabilities between each other. Each also requires a unique U-Boot partition that gets read before the FreeBSD kernel is loaded. I strongly favor the current approach that has a custom kernel configuration file and U-Boot for each SOC. All of the common ARM systems have a limited amount of real estate to store FreeBSD kernel and base system because it all must fit on a SD memory card. Having a GENERIC kernel that covers all SOC variants would consume flash space that will never be used. Tom -- Public Keys: PGP KeyID = 0x5F22FDC1 GnuPG KeyID = 0x620836CF