[U-Boot-Users] PPC405H ethernet receive problems

omnium at ziplip.com omnium at ziplip.com
Thu Jan 29 13:48:44 CET 2004

Hi, I'm new!

I am porting u-boot to a custom board with a NP405H processor and an Intel LXT973 dual phy.

I have had a lot of success so far:  I have brought the board up and can boot the kernel (without networking).

My network setup is different to the standard eval boards such as the IBM Ash board.  I am using MII to talk to the phy with EMAC0 and 2, the ASH uses RMII.  Currently I am only trying to support EMAC0 and ignore EMAC2.

So far, the only mod I have made to cpu/ppc4xx/405gp_enet.c is to add to the start of ppc_4xx_eth_init:

    out32 (ZMII_FER, ZMII_MDI0 | ZMII_MII0 | ZMII_MII2);
    out32 (ZMII_SSR, 0x55550000);

(this is just before the "/* EMAC RESET */" comment).  This should place my cpu into MII mode at the correct speed for my test network.

I can transmit bootp requests and I can send out ARP requests as part of a ping.  I verified this using Ethereal on my Linux host.

My problem is reception.  I see nothing!  The receive LED blinks on the PHY and Ethereal shows DHCP_OFFER messages in response to the request or ARP messages in response to a ping.

Debugging using a Lauterbach (sorry, it's not a BDI2000!) shows that I never get a breakpoint on "enetInt" and therefore never receive any packets.

Unfortunately, I am fairly clueless when it comes to this chip and ethernet in general and hope that someone could point out some likely problems.

I have tested reception on the EMAC using some hardware test software written by a colleague, so I know that it CAN receive data.  However, this program polls the EMAC rather than uses interrupts to receive data.

I suspect that using MII rather than RMII may be a clue, but don't know where to proceed.

Any help would be appreciated.  Please excuse me if I've missed any obvious details.

Many thanks,
Ryan Harkin.

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