[U-Boot] [PATCHv5 00/21] Retrieve MAC address from EEPROM

York Sun york.sun at nxp.com
Mon Apr 10 15:52:26 UTC 2017


On 04/10/2017 08:34 AM, Olliver Schinagl wrote:
> First off:
> P.S. Joe, for some reason my previous patches where added with me as:
> "oliver at schinagl.nl <oliver at schinagl.nl>" I see that it comes from patchwork
> as such. Is there some way to fix this to
> "Olliver Schinagl <oliver at schinagl.nl>"?
>
> Below the updated summary:
>
> This patch-series introduces methods to retrieve the MAC address from an
> onboard EEPROM. The series does a few small cleanups at the start, as either
> I ran into them while doing this series and fixed them along the way or
> actually depended on them.
>
> A manufacturer wants to produce boards and may even have MAC addresses for
> boards. Maintaining unique environments on a per-board basis however is
> horrible. Also this data should be very persistent, and not easily deletable
> by simply wiping the environment or device tree. Finally there are
> chips available on the market with a pre-programmed MAC address chips
> (proms)
> that a board manufacturer wants to use. Because of this, the MAC needs to be
> stored be able to read from such an 'external' source.
>
> The current idea of the eeprom layout, is to skip the first 8 bytes, so that
> other information can be stored there if needed, for example a header
> with some magic to identify the EEPROM. Or equivalent purposes.
>
> After those 8 bytes the MAC address follows the first macaddress. The
> macaddress is appended by a CRC8 byte and then padded to make for nice 8 bytes.
> Following the first macaddress one can store a second, or a third etc etc
> macaddress.
>
> The CRC8 is optional (via a define) but is strongly recommended to have. It
> helps preventing user error and more importantly, checks if the bytes
> read are actually a user inserted address. E.g. only writing 1 macaddress into
> the eeprom but trying to consume 2.

Interesting solution. We have used EEPROM to store board ID, version 
number, MAC addresses on many of our boards. We have a command "mac" to 
read/write these addresses. Would you take a look to see if it is 
possible to integrate?

York


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