From owner-freebsd-arch@FreeBSD.ORG Fri Apr 3 19:01:40 2009 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BD2DD106566C for ; Fri, 3 Apr 2009 19:01:40 +0000 (UTC) (envelope-from ccna.syl@gmail.com) Received: from mail-qy0-f134.google.com (mail-qy0-f134.google.com [209.85.221.134]) by mx1.freebsd.org (Postfix) with ESMTP id 61AF88FC16 for ; Fri, 3 Apr 2009 19:01:40 +0000 (UTC) (envelope-from ccna.syl@gmail.com) Received: by qyk40 with SMTP id 40so2280117qyk.3 for ; Fri, 03 Apr 2009 12:01:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :received:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=FnTyCnIz/UDok4eOagMloUIzhbhE4BnjmEvK6BNlpII=; b=RTiX+eqMpDFGltY5eFdvLJx+HgIBIsThqBAPbZAvMVf+QjFN7y7cbiyBBD6tF86eAC oLcyiHki3DbKHFnikg5XGwRMpLI9tcoSDgK1XFe7jjnbXXG7AEwaIe2ZsYeuoDiTqA6E DIx6BQUCXFog9XbOBojjKfw8w3qrZB9yGX1qo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=i9sIapxSOiEi8fEKZWpQue8EAA5jq3hbvWpKMzzeJuAEwjpBVsD6my3nrpnMqOOew+ 7aH9MeZc7iYiqLVY88w03i3fvlOVO/ajt8dAha4gOISHPGXjKdd8/IV686Nlike58GD/ kevFVhCGX+3yi/vtXTgPSnFH5DOlP7O62h0m4= MIME-Version: 1.0 In-Reply-To: <821081.71230.qm@web7703.mail.in.yahoo.com> References: <821081.71230.qm@web7703.mail.in.yahoo.com> Date: Fri, 3 Apr 2009 20:40:02 +0200 Received: by 10.231.20.2 with SMTP id d2mr380652ibb.37.1238784017476; Fri, 03 Apr 2009 11:40:17 -0700 (PDT) Message-ID: <164b4c9c0904031140n2ec05068q4406120907bdbae0@mail.gmail.com> From: Sylvestre Gallon To: Kamlesh Patel Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Cc: freebsd-arch@freebsd.org Subject: Re: GSoC 2009 Project proposal Review X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Apr 2009 19:01:41 -0000 On Fri, Apr 3, 2009 at 7:52 PM, Kamlesh Patel w= rote: > Hi, > > I > am applying for a FreeBSD Project =93NAND Flash driver support=94 in GSoC= 2009. I got this group id from M. Warner Losh. > I have a schedule how i am planning to finish this project in summer. Cou= ld anyone please tell me if the estimated time of the tasks or dependencies= between the tasks are not correct or need modification? > > > > > April 20-May 23:=A0=A0=A0 Study FreeBSD driver APIs and NAND command sets > May 23-June 6:=A0=A0=A0=A0 Write FreeBSD driver skeleton for GEOM driver. > June 7-June 13:=A0=A0=A0 Implement probe and attach routines. Implement G= EOM ioctls suck that diskinfo will work on the device > > June 14-June 20:=A0 Implement ECC routines > June 21-July 4:=A0=A0=A0=A0 Implement and test read support > July 5-July 11:=A0=A0=A0 =A0 Implement and test write support > July 13:=A0=A0=A0 =A0=A0 =A0 =A0 =A0 =A0=A0 Mid term evaluation of progre= ss > July 12-July 25:=A0=A0 Implement bad block support > July 26-Aug 15:=A0=A0 Get ufs working on the flash device, tune performan= ce. > Aug 16-Aug 22:=A0=A0 Write man page for driver > Aug 24th=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0=A0=A0 Final evalution > > Thank you in advance > Kamlesh > MS CS CSUS > Hi, I am not a FreeBSD developer but I have got some interest in Nandflash and I've got some question for you. I found this topic interesting. How do you plan to implement this driver : do you want to develop only some flash layer or add row nand support just under geom. Have you take a look on some project like uffs (http://uffs.org/) to design the nandflash architecture ? In your timeline you do not talk about ware leveling, do you have take time to think about it ? Without wear leveling a nandflash with a common filesystem on is back will only work for one or two weeks... You don't talk about bad blocks too, how do you think you can handle them ? I hope that my question will help you :) Cheers, --=20 Sylvestre Gallon (http://devsyl.blogspot.com) Fifth Grade Student @ Epitech & Researcher @ LSE R&D @ Rathaxes (http://www.rathaxes.org)