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From: Wolfgang Denk <wd@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] fsl: board EEPROM has the CRC in the wrong location
Date: Fri, 13 Jul 2012 23:32:42 +0200	[thread overview]
Message-ID: <20120713213243.071AE2000F2@gemini.denx.de> (raw)
In-Reply-To: <50009349.9000609@freescale.com>

Dear Timur Tabi,

In message <50009349.9000609@freescale.com> you wrote:
> 
> > In case you have an EEPROM with correct layout (CRC at 0xFC) but
> > incorrect CRC, you will access random data and interpret this as CRC.
> > This is provoking undefined behaviour.
> 
> True, but it doesn't matter.  The EEPROM is not that important, and the
> odds of screwing this up is one in four billion.
> 
> > If you want, then rather provide an update tool that theuser can use
> > (manually!) to update, but this should be done once, and with explicit
> > confirmation from the user, never automagically.
> 
> Considering how unimportant the EEPROM really is, I don't see the point in
> making it so complicated.  We already automagically upgrade the board from
> NXID v0 to NXID v1.  Now we automagically fix boards that have the CRC in
> the wrong place.
> 
> Anyway, I don't see why it's so controversial.  This code is only used on
> a small number of Freescale reference boards.

Well, if it's really so unimportant and used in only a small number
of boards, then just omit this broken code that provokes the
undefined behaviour.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The main thing is the play itself. I swear that greed for  money  has
nothing  to  do with it, although heaven knows I am sorely in need of
money.                                           - Feodor Dostoyevsky

  reply	other threads:[~2012-07-13 21:32 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-12 21:46 [U-Boot] [PATCH] fsl: board EEPROM has the CRC in the wrong location Timur Tabi
2012-07-12 22:03 ` sun york-R58495
2012-07-12 22:37   ` Scott Wood
2012-07-12 22:44     ` Timur Tabi
2012-07-12 22:46     ` sun york-R58495
2012-07-12 22:49       ` Scott Wood
2012-07-12 22:52         ` Timur Tabi
2012-07-13  4:32           ` Wolfgang Denk
2012-07-13 12:11             ` Tabi Timur-B04825
2012-07-13 21:26               ` Wolfgang Denk
2012-07-13  4:30   ` Wolfgang Denk
2012-07-13  4:38     ` sun york-R58495
2012-07-13 12:12       ` Tabi Timur-B04825
2012-07-13 21:22         ` York Sun
2012-07-13 12:10     ` Tabi Timur-B04825
2012-07-13 21:25       ` Wolfgang Denk
2012-07-13 21:29         ` Timur Tabi
2012-07-13 21:32           ` Wolfgang Denk [this message]
2012-07-13 21:39             ` Timur Tabi
2012-07-13 21:45         ` Scott Wood
2012-07-13 21:53           ` Timur Tabi
2012-07-13 22:19             ` Scott Wood
2012-07-13 22:22               ` Timur Tabi
2012-07-13 22:41                 ` Scott Wood
2012-07-13 22:46                   ` Timur Tabi
2012-07-13 22:54                     ` Scott Wood
2012-07-13 23:01             ` Wolfgang Denk
2012-07-13 23:12               ` Scott Wood
     [not found]                 ` <C5EFF1F960B6FC4C873CF9BD5FE250210791DCC8@039-SN2MPN1-013.039d.mgd.msft.net>
2012-07-15 12:52                   ` Tabi Timur-B04825
2012-07-16 19:57                 ` Wolfgang Denk
2012-07-16 22:32                   ` Scott Wood
2012-07-13 22:59           ` Wolfgang Denk

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