From owner-freebsd-arm@FreeBSD.ORG Thu Jul 12 02:29:16 2012 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 34D4F106566C for ; Thu, 12 Jul 2012 02:29:16 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from mail-gg0-f182.google.com (mail-gg0-f182.google.com [209.85.161.182]) by mx1.freebsd.org (Postfix) with ESMTP id D993A8FC14 for ; Thu, 12 Jul 2012 02:29:15 +0000 (UTC) Received: by ggnm2 with SMTP id m2so2226656ggn.13 for ; Wed, 11 Jul 2012 19:29:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=sender:subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer :x-gm-message-state; bh=cIdKL9tn+LWBF3+84zEjiANFkV37myFIr9KKyby0MRU=; b=b47gn8wenTWZN7WloaXUS3Jpuo5X8Td1q4wQ87WdPPcew4jlAtJd26ZwYXHJ2rSuG6 AfHUFA/gu39E8udfGv+1CY2LmqgQstoOh9QoPTu9BL/H2rsVeuhSjOImsqo2fraM1H+O K4Y8fbnS6wyKjvEfGua/6FE4WAtRV6HSKD+PuoVm9ffsH7eRAtwytHXxIO3wC1Bfv84m s8ty6ChUOpIdXHepiky8hrSHZr7X2xKh+DcITDX2Zz1vWHPy2koyJquJqpvbYCjSqz7p xmDCHY3ZfZ6B2Obkd7nYyCj4m1W1CFHQ77mTfb3BzOg3ghvcNSsC3QL3LTBvtmy7eObT zgVQ== Received: by 10.50.156.196 with SMTP id wg4mr16426737igb.54.1342060149055; Wed, 11 Jul 2012 19:29:09 -0700 (PDT) Received: from 63.imp.bsdimp.com (50-78-194-198-static.hfc.comcastbusiness.net. [50.78.194.198]) by mx.google.com with ESMTPS id k5sm15824622igq.12.2012.07.11.19.29.07 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 11 Jul 2012 19:29:08 -0700 (PDT) Sender: Warner Losh Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii From: Warner Losh In-Reply-To: <2FFA7683-9919-4BB9-9B65-F49494572FB2@freebsd.org> Date: Wed, 11 Jul 2012 20:29:06 -0600 Content-Transfer-Encoding: quoted-printable Message-Id: <9532201C-0E39-4E2E-A2D8-CBCF4FB219DC@bsdimp.com> References: <422C3A88-2AC6-484E-A34D-CC61EB761DC2@FreeBSD.org> <2FFA7683-9919-4BB9-9B65-F49494572FB2@freebsd.org> To: Tim Kientzle X-Mailer: Apple Mail (2.1084) X-Gm-Message-State: ALoCoQlGVIacO1xH6PjTEBndobc/aegnAXuG3hCUFrN1gVoMQ8jjssFHR0Vvx0yCUAKUXhu/ck4n Cc: freebsd-arm@freebsd.org, David Chisnall Subject: Re: ARM at the Cambridge DevSummit X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to the StrongARM Processor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Jul 2012 02:29:16 -0000 On Jul 11, 2012, at 8:13 PM, Tim Kientzle wrote: >=20 > On Jul 11, 2012, at 6:10 AM, David Chisnall wrote: >=20 >> Hello all of the FreeBSD/ARM flavoured people, >>=20 >> The Cambridge DevSummit in August will be attended by some people = from ARM, so it would be good to have as many FreeBSD/ARM developers = there as possible. If you haven't signed up yet, please do. >>=20 >> Please also let me have a list of topics that you'd like to discuss = with people from ARM so that I can try to make sure that relevant people = attend. >=20 > I won't be able to attend, but after some recent work on > ARM booting, I'm very curious if there are emerging > conventions (I hesitate to use the word "standards") > for how ARM systems boot. There's two standards that we can/should follow. First, there's uldr, = which is the uboot + /boot/loader path. This works well enough, but has = a weak point here and there. The FDT stuff is the future for most ARM = platforms, but currently is limited to the Marvel SoCs (where it is = pretty much mandatory). I believe we should adapt this for the new = armv6 families that are coming in, since new Linux platforms have to = support it, and these are "new" by that definition. The second is a more direct interface to uboot. Or rather a more direct = interface to the Linux standard booting protocol. I've made some = sketches on the wall, and filled in a few things here. However, it is = very incomplete. I've been unable to test it because I've been unable = to build a bootm compatible image yet, and uboot only uses the Linux ABI = when you boot with bootm. For the 'go' interface that's documented on = the FreeBSDAtmel wiki page, args are passed in another way. I can boot = with that, but not bootm. To be honest, I've not tracked the problem = much yet, other than to notice it... > Warner's been talking about working towards a true > GENERIC kernel on ARM. That looks almost feasible, > but we still seem a long ways from being able to build > a generic bootloader. Yes. There's the whole point of the boot args stuff I've done: to try = to have a standardish interface to the kernel. All the boot loader = interfaces would parse the goo from the boot loader and set = variables/structures in the kernel that the rest of the kernel = interfaces to. > Is this likely to change? I'd like it to, but it is a lot of work, and there's a lot of = rototilling to do in the Atmel area... Warner=