From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751852AbdFELSS (ORCPT ); Mon, 5 Jun 2017 07:18:18 -0400 Received: from mail-wr0-f172.google.com ([209.85.128.172]:33860 "EHLO mail-wr0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751400AbdFELSQ (ORCPT ); Mon, 5 Jun 2017 07:18:16 -0400 Date: Mon, 5 Jun 2017 13:18:13 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: Richard Weinberger Cc: Joern Engel , David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Cyrille Pitchen , Artem Bityutskiy , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/5] Extends block2mtd and ubi drivers Message-ID: <20170605111813.GD14675@pali> References: <1496418222-23483-1-git-send-email-pali.rohar@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 02 June 2017 18:17:06 Richard Weinberger wrote: > Pali, > > Am 02.06.2017 um 17:43 schrieb Pali Rohár: > > This patch series extends block2mtd and ubi drivers to better handle > > read-only devices and allow to load UBI image from local file which was > > created for nand device. > > > > Tested for Nokia N900 with Maemo 5 rootfs ubifs image > > (rootfs_RX-51_2009SE_21.2011.38-1_PR_MR0) which has erase size 128k, > > write size 2k and nand subpage shift 2. > > What is the use case behind this series? Take existing ubi image (where is one ubifs volume) and unpack it. Or rather unpack-modify-pack to do some small changes. > Did you see my nandsim rework some time ago? > http://lists.infradead.org/pipermail/linux-mtd/2016-September/069422.html No yet. I have my patches since 2012, but I decided after cleaning up them to send... As I think they could be useful for other people. > If you need a way to load files/nanddumps as NAND devices, this should be a good > starting point. > This reminds me that I need to revive that series. :-) nandsim.ko has problem that needs to be loaded with special parameters compatible with characteristic of target nand for which is ubi image prepared. Plus it is nand similator and not layer to translate arbitrary file image on disk to mtd device. block2mtd is what is doing this part. > > $ losetup -r /dev/loop0 rootfs_RX-51_2009SE_21.2011.38-1_PR_MR0.ubifs > > $ echo -n /dev/loop0,131072,2048,2 > /sys/module/block2mtd/parameters/block2mtd > > $ ubiattach -p /dev/mtd0 > > $ mount /dev/ubi0_0 /mnt/ubi -t ubifs > > ... > > $ umount /dev/ubi0_0 > > $ ubidetach -p /dev/mtd0 > > $ echo -n del=/dev/loop0 > /sys/module/block2mtd/parameters/block2mtd > > $ losetup -d /dev/loop0 > > The module-parameter interface is odd. IMHO we should not extend it. That file is used for adding new mapping from block device to mtd device. Currently there is no other way how to specify that mapping or removing mapping. If you have better idea, let me know and I would try to implement it. -- Pali Rohár pali.rohar@gmail.com