[U-Boot] [u-boot] CRC / ECC protection of environment

[Arno Steffen]

2011/9/20 Wolfgang Denk <wd at denx.de>:
> Dear Arno Steffen,
>
> In message <CAACX+R1vfc7C7XvygfVD8TV+ypaqSyON_EFX7VheQ8R56vncaA at mail.gmail.com> you wrote:
>> Assumed Uboot and environment are located in NAND flash.
>> Just a short question: Is the ECC done before the CRC check, or is the
>> CRC check done first?
>> From my observation I would assume that first CRC is checked. But if
>
> Your observations are wrong.
>
>> so - imho in my case (environment in NAND, which is handled with ECC)
>> this wouldn't make sense.
>> Am I right, that in this situation I should configure uboot to NOT use
>> CRC protection?
>
> No, you should not meddle with the CRC checking.
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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>

Thank you for clarification. Although I am estonished, that after some
time of running 2 devices come up with CRC errors (with just read
access to environment!!).
Unfortunatly I don't know a way just to change 1 bit in flash without
changing the OOB data to simulate a toogling bit.

Best regards
Arno