Re: [ECOS] A clue....

[Gary Thomas <gary at mlbassoc dot com>]

On Wed, 2006-02-15 at 16:28 +0100, Andrew Lunn wrote:
> On Wed, Feb 15, 2006 at 05:08:30AM -0800, Chuck McManis wrote:
> > At 04:37 AM 2/15/2006, Andrew Lunn wrote:
> > >Does it known its own MAC address? Where does it get it from? When it
> > >sends out the ARP request what does it use for its own address?
> > 
> > Yes, it does. This is the bit of the log that shows the eCos target trying 
> > to ARP:
> > 
> > ##Tx descriptor index 0 TDES 0012c090 buffer 0012c0d0
> > TxEvent:  len: 0x002a
> > Packet data at 0x0012c0d0
> > ff ff ff ff ff ff 75 17 c7 05 04 4d 08 06 00 01 08 00 06 04 00 01 75 17 c7 
> > 05 04 4d c0 a8 6e b1 6e ff 00 8a 00 8a c0 a8 6e 1e
> > Padded 42 byte packet to 60 bytes
> > Before TX: Desc (@0x0012c090) 80000000 00e0803c 0012c0d0 0012c0a0
> >  Next (@0x0012c0a0) 00000000 00e0803c 0012c6d8 0012c0b0
> > vt8235_send:END: ints at TX: 00
> > 
> > As you can see the destination address is FF:FF...FF but the source address 
> > is 75:17:C7:05:05:4D which is the correct MAC address for the card. 
> 
> This just shows that eCos knows the MAC address. Does the card know
> the MAC address? Sometimes you need to write the MAC address into a
> register before it will receive any packets addressed to it.

Also, a common error is not getting the bits/bytes correct in the 
registers so that the chip does not recognize the 48-bit value that
was sent in the ethernet packet.

-- 
Gary Thomas <gary@mlbassoc.com>


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