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Re: DECstation ESAR checksum?

To: linux-mips@fnet.fr
Subject: Re: DECstation ESAR checksum?
From: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Date: Sat, 26 Sep 1998 12:45:00 +0200
In-reply-to: <Pine.LNX.3.95.980925195849.451A-100000@whale.dutch.mountain>; from Richard van den Berg on Fri, Sep 25, 1998 at 08:00:46PM +0200
References: <Pine.LNX.3.95.980925195849.451A-100000@whale.dutch.mountain>
On Fri, Sep 25, 1998 at 08:00:46PM +0200, Richard van den Berg wrote:
> Is there someone able to tell how the checksum of the Ethernet Station
> Address ROM is calculated? This is the ROM layout with 'ba' being the
> base address of the ROM:

I've checked my AMD manuals and couldn't find an exact algorithm for doing it.
And as you can't attach the address prom directly to the lance and c-lance
like it's possible with the PCnet chips, it's probably up to the hardware
designer how to calculate the checksum.

FYI, the pcnet has 16 bytes of address prom. 0 to 5 are the address octets,
6 to 11 is unused, 12 (LSB) and 13 (MSB) is the checksum, 14 and 15 should 
be 0x57. The checksum is calculated over 0 to 11, 14 and 15.

Thomas.

-- 
See, you not only have to be a good coder to create a system like Linux,
you have to be a sneaky bastard too ;-)
                   [Linus Torvalds in <4rikft$7g5@linux.cs.Helsinki.FI>]

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