From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marek Vasut <marex@denx.de>
Date: Fri, 19 Jul 2013 15:55:25 +0200
Subject: [U-Boot] [RFC][DFU] Unification of dfu_alt_info alt settings
	description + command execution
In-Reply-To: <51E8C46E.5040103@denx.de>
References: <20130716173521.3dd7ec9e@amdc308.digital.local>
	<201307181710.05980.marex@denx.de> <51E8C46E.5040103@denx.de>
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To: u-boot@lists.denx.de

Dear Heiko Schocher,

> Hello Marek,
> 
> Am 18.07.2013 17:10, schrieb Marek Vasut:
> > Hi,
> > 
> >> Dear Heiko Schocher,
> >> 
> >> In message<51E77A1D.90403@denx.de>  you wrote:
> >>>> Try "nand write.trimffs" to write UBI images produced with ubinize .
> >>> 
> >>> This solves not the erasecounter problem, or?
> >>> 
> >>> For UBI we need something like this:
> >>> http://www.linux-mtd.infradead.org/doc/ubi.html#L_flasher_algo
> >>> 
> >>> But I am not an UBI expert. It is possible I overlook something
> >>> obvious ...
> >> 
> >> No, you don't.  Devices managed by UBI should never be erased by
> >> other, non-UBI-aware tools.
> > 
> > I based my reply on the following commit in U-Boot and the fact that
> > write.trimffs is used to flash UBI images. Maybe I was wrong?
> > 
> > commit c9494866df835bcee68e17339aec1090faa704da
> > Author: Ben Gardiner<bengardiner@nanometrics.ca>
> > Date:   Tue Jun 14 16:35:07 2011 -0400
> > 
> >      cmd_nand: add nand write.trimffs command
> >      
> >      Add another nand write. variant, trimffs. This command will request
> >      of nand_write_skip_bad() that all trailing all-0xff pages will be
> >      dropped from eraseblocks when they are written to flash as-per the
> >      reccommended behaviour of the UBI FAQ [1].
> >      
> >      The function that implements this timming is the drop_ffs() function
> >      by Artem Bityutskiy, ported from the mtd-utils tree.
> >      
> >      [1] http://www.linux-mtd.infradead.org/doc/ubi.html#L_flasher_algo
> 
> Yes, that sounds as a step in the right direction, but where are
> the erasecounters handled, as described in [1] ?

I don't think they're handled anywhere.

> And as this is a "ubi function" and not nand specific, the command
> should start with "ubi ..." ... as we have a "ubi write ...", but
> ubi write is only for ubi volumes ... i tend to say, we need a
> "ubi format ..." similiar to ubiformat in the mtd utils [2] ...
> 
> [2] http://git.infradead.org/mtd-utils.git
>      ubiformat found in /ubi-utils/ubiformat.c

Full agreement.

Best regards,
Marek Vasut