[U-Boot-Users] ENV in NAND and in EEPROM ?

[Aras Vaichas]

Manuel Sahm wrote:
>
> Hello,
>
>  
>
> I want to use an eeprom AND an NANDFLASH for storing the Enviroment Data.
>
>  
>
> First: The EEPROM should be connected via SPI, so I have to make a c
> file within the function for spi_write and spi_read…to use it with the
> CFG_CMD_EEPROM.
>
> right ?
>
>  
>
> Now my second question:
>
> I want to achieve that the uboot first looks in NANDFlash, if the ENV
> is damaged, look at NANDFLASH_REDUNDAND area [This is what is normally
> implemented, I think, and it works], now if these both areas of NAND
> Flash are damaged, the ubbot should have a lokk at the eeprom to load
> its environment…
>
>  
>
Why so many backup areas? Is your hardware prone to multiple mass
failures? Perhaps you have a hardware problem that needs fixing.

Did you know that the U-Boot binary image itself contains the original
copy of the environment? This is the safest and best backup you can use.
I would use the EEPROM to load in particular changes to specific U-Boot
variables.

> Is it possible ??
>
With a little effort. Normally the environment is only stored in one
place and switched on/off via #defines. I predict a fair amount of
restructuring would be necessary but it depends on how you want to go
about it, really.

> What files do I have to adapt, and where�s the point in the code,
> where the printenv/setenv command is attached to the NANDFLASH/EEPROM
> Function to load the data ?
>
Do you know the "grep" command? Try "man grep".

Then try in your U-Boot source directory.
# grep -r "saveenv" *
or
# grep -ir "environment" *

 

If you are able to find the code yourself then you will learn the U-Boot
codebase a little better.

Aras



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