[PATCH v2 2/3] ep93xx: added chip revision reading function

Martin Guy martinwguy at gmail.com
Sat Mar 20 15:48:21 EDT 2010


On 3/20/10, H Hartley Sweeten <hartleys at visionengravers.com> wrote:
>  The ep93xx unique serial number, also called the MaverickCrunch ID, can
>  be found in the Sercurity registers.  There are actually two of them.
>  One is a 32-bit unique ID the other is a 128-bit random ID.  Random
>  meaning random per chip not per boot since it is created by means of
>  fuseable links on the chip that are set during manufacture.  These
>  also are not currently exposed to the user in any fashion.
>
>  I had submitted a patch previously that adds an architecture specific
>  extension to /proc/cpuinfo that would allow exposing this information
>  on the ep93xx.  The same extension could be used on platforms like the
>  TS-7200 to show the jumper settings on the board.
>
>  If there is any interest I will re-post that patch series.

Thanks.

Yes, being able to see the unique ID is certainly useful. I use this
in userspace to set a different MAC address on each board for DHCP
purposes in a classroom of otherwise identical diskless X terminals
based on this chip.

    M



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