From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Cooper Date: Fri, 6 May 2011 14:33:59 -0400 Subject: [U-Boot] understanding mkimage a bit more In-Reply-To: References: <20110506173352.25100@gmx.net> Message-ID: <20110506183359.GC20845@localhost> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Fri, May 06, 2011 at 11:13:39AM -0700, Charles Krinke wrote: > The next issue is the flash file system. Normally, I like to use JFFS2 > for reliability as embedded devices frequently have their power switch > turned off at any time. I do understand that UBIFS is getting more > prevalent lately and I wonder if you or anyone else has a comment on > the suitability of UBIFS in an environment where the power will be > turned off and on exexpectdly and frequently. > > In googling UBIFS problems, I do see posts across the internet of > UBIFS devices that will not boot after power is turned off and on. My > experience with JFFS2 is that it has always recovered during boot with > all the designs I have participated in over the last several years. > Admiteddly, the act of doing something like "scandisk" on boot slows > the boot down, but does seem to add reliability. It has been very resilient to power failures in my experience -- the Linux ubifs code has always managed to recover, and very quickly. The main pitfall is that U-Boot's support for ubifs is only the read-only subset of Linux's. That means it can read from a consistent ubifs partition, but not from one that needs repair (because that requires writing). So you can't rely on booting your Linux kernel *from a ubifs partition*. But if you have your kernel in a separate, read-only uImage partition you should be fine (it's just more annoying to update kernels). -- Eric Cooper e c c @ c m u . e d u