[U-Boot-Users] how to use 'eeprom read' command

[U-Boot-Users] how to use 'eeprom read' command

[Sachin]

Hi,

I want to read boot eeprom using u-boot.
Can you tell me which 'addr' I need to pass to the 'eeprom read' command?

--------------------------------------------------------------------------
=> help eeprom
eeprom read  devaddr addr off cnt
eeprom write devaddr addr off cnt
       - read/write `cnt' bytes from `devaddr` EEPROM at offset `off'

--------------------------------------------------------------------------

I want to access boot eprom which is at 'devaddr' 0x54 and offset '0' to 
'10'.

But I am not clear what ro pass for the 'addr' argument.

Regards,
Sachin Rane

[U-Boot-Users] how to use 'eeprom read' command

[Jerry Van Baren]

Sachin Rane, Alphion Communications wrote:
> Hi,
> 
> I want to read boot eeprom using u-boot.
> Can you tell me which 'addr' I need to pass to the 'eeprom read' command?
> 
> --------------------------------------------------------------------------
> => help eeprom
> eeprom read  devaddr addr off cnt
> eeprom write devaddr addr off cnt
>        - read/write `cnt' bytes from `devaddr` EEPROM at offset `off'
> 
> --------------------------------------------------------------------------
> 
> I want to access boot eprom which is at 'devaddr' 0x54 and offset '0' to 
> '10'.
> 
> But I am not clear what ro pass for the 'addr' argument.
> 
> Regards,
> Sachin Rane

IIRC, "addr" is the memory (RAM) address that you read the eeprom data 
into or is the source tow rite the eeprom data out.  To read your i2c 
device 0x54, you would do something like:
   eeprom read 54 0 0 10
and then would be able to see the 16 bytes of data with the md command:
   md 0

Hope I'm not lying,
gvb

[U-Boot-Users] how to use 'eeprom read' command

[Stefan Roese]

On Monday 24 September 2007, Jerry Van Baren wrote:
> IIRC, "addr" is the memory (RAM) address that you read the eeprom data
> into or is the source tow rite the eeprom data out.  To read your i2c
> device 0x54, you would do something like:
>    eeprom read 54 0 0 10
> and then would be able to see the 16 bytes of data with the md command:
>    md 0
>
> Hope I'm not lying,

No, you are correct. But I would suggest to not use RAM address 0, because on 
some architectures the lower address range is reserved for exception vectors.

So please use:

=> eeprom read 54 100000 0 10

to read the first 16 (0x10) bytes to address 0x100000 (1MByte) in RAM.

Best regards,
Stefan

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