From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luigi 'Comio' Mantellini Date: Wed, 16 Apr 2008 15:55:32 +0200 Subject: [U-Boot-Users] MTD Concat support In-Reply-To: <4805F995.6090301@comsys.ro> References: <1208342660.26135.33.camel@localhost> <4805E73E.5050604@comsys.ro> <1208348770.26135.51.camel@localhost> <4805F995.6090301@comsys.ro> Message-ID: <1208354132.26135.61.camel@localhost> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Vlad and list, see inline comments. On mer, 2008-04-16 at 16:05 +0300, Vlad Lungu wrote: > Luigi 'Comio' Mantellini wrote: > > .. cut... > > > > The answer is pretty simple: the flash layout is a project > > constraint :D. I know that this approach is very slow, but the target > > application is a device that should be rebooted about once in a year. > > > > Well, it all depends if you really mean loopback or if it is ramdisk. > Loopback feels totally wrong unless the rootfs is read-only. The rootfs will be Read-only. Any write access will be redirected to a ramdisk. Only during the "upgrading" activity the JFFS2 will be write from an custom user application, while during the normal activity both JFFS2 and loopback-mounted Root filesystem will be Read-only. > Really. > If it is ramdisk, I guess you could store uImages directly in the NOR > flash (one at the beginning, one at the end so you know you can > easily replace any of them, or if you know that they are <9Mo, 3 of them > equally spaced). I cannot store the uImages in separated memory space... > > Anyway, back to your original question: if the flash devices are > identical and the erase sectors have the same size, you could probably > fill flash_info[] yourself instead of auto-detecting and pretend you > have a single flash twice the size (i.e. 32Mo). After all, this is NOR > flash so you're not actually using sector numbers like with NAND parts. > And the addresses are consecutive, so for all intents and purposes, > it looks like a big flash until you do READ_ID. > Ok. This can be a solution. thanks luigi > Vlad > -- ______ Luigi Mantellini .'______'. R&D - Software (.' '.) Industrie Dial Face S.p.A. ( :=----=: ) Via Canzo, 4 ('.______.') 20068 Peschiera Borromeo (MI), Italy '.______.' Tel.: +39 02 5167 2813 Fax: +39 02 5167 2459 Ind. Dial Face Email: luigi.mantellini at idf-hit.com www.idf-hit.com GPG fingerprint: 3DD1 7B71 FBDF 6376 1B4A B003 175F E979 907E 1650