Aw: Re: Re: errors copying UBI volumes

[iw3gtf at arcor.de]

Hi,

> On Thu, Sep 15, 2016 at 01:13:14PM +0200, iw3gtf at arcor.de wrote:
> > Hi Sascha,
> > 
> > thanks for the answer,
> > 
> > > Hi Giorgio,
> > > 
> > > On Wed, Sep 14, 2016 at 05:52:32PM +0200, iw3gtf at arcor.de wrote:
> > > > Hi,
> > > > 
> > > > I'm working on an embedded board with an iMX25 arm CPU and a nand
> flash.
> > > > 
> > > > The board runs a linux kernel/userland.
> > > > 
> > > > When the user updates the firmware, the running userland/kernel
> creates
> > > some
> > > > new ubi volumes on the nand, let's say 'kernel_next' and
> 'userland_next'.
> > > > On the next system reboot barebox looks if it finds, lets say, the
> > > 'kernel_next' volume
> > > > and, in this case, it removes the old one ('kernel'), creates a new,
> empty
> > > one ('kernel'),
> > > > copies 'kernel_next' to the just created 'kernel' and finally removes
> the
> > > 'kernel_next'
> > > > to complete the update.
> > > 
> > > While this should work, why so complicated? Since this commit:
> > > 
> > > | commit 892abde56c1c5a62d49d8b70c73e5d388e74345d
> > > | Author: Richard Weinberger <richard at nod.at>
> > > | Date:   Mon Nov 24 22:30:10 2014 +0100
> > > |
> > > |    UBI: rename_volumes: Use UBI_METAONLY
> > > |    
> > > |    By using UBI_METAONLY in rename_volumes() it is now possible to
> rename
> > > |    an UBI volume atomically while it is open for writing.
> > > |    This is useful for firmware upgrades.
> > > 
> > > It should be possible to just remove 'kernel' and rename 'kernel_next'
> to
> > > 'kernel'
> > > without bootloader intervention.
> > 
> > This is a very good news for me, I already wanted to ask for a UBI rename
> feature.
> > Could you please elaborate a bit on this point: I looked for a shell
> command like the
> > 'ubirename', present in the 'mtd-utils' package, but could not find it.
> Maybe we just
> > need a new command implemented in '<barebox_root>/commands/ubi.c'.
> 
> You can add a ubirename command, patches welcome. Anyway, I suggested to
> rename it under Linux since you write your new Kernel/rootfs under Linux
> aswell.
> 

OK, I think I'll try to write a new command in commands/ubi.c and if it
results in something usable I'll send a patch to be reviewed.

giorgio


Giorgio, iw3gtf at arcor.de