[U-Boot-Users] bootloader MAC
ngustavson at emacinc.com
Fri Jun 9 19:58:05 CEST 2006
On Friday 09 June 2006 11:56 am, Wolfgang Denk wrote:
> Otherwise you should have discovered the e100_eeprom_read() resp.
> read_eeprom() functions in these drivers which do - guess what? -
> read the MAC address from EEPROM.
> The cards you used as example actually *do* have code in their
> drivers to read the MAC address from the EEPROM and program it into
> the controller. You see?
I'm going through the e100.c code now.
The drivers do have code to read and write the MAC address, but I don't see
any reference to them actually doing this during normal operation.
This sort of thing may give you the capability to write the MAC into the
device if ifconfig, but that would be something the OEM would do once and
then leave alone.
There is a section fo code in e100 that reads out the MAC:
memcpy(netdev->dev_addr, nic->eeprom, ETH_ALEN);
DPRINTK(PROBE, ERR, "Invalid MAC address from "
err = -EAGAIN;
But this reads out the MAC into a net device, registering it's MAC with the
OS, not loading into the physical device.
(on page 35 of the 82559ER Fast Ethernet PCI Controller data sheet)
The 82559ER performs an automatic read of seven words (0H, 1H, 2H, AH, Bh, Ch
and DH) of the
EEPROM after the de-assertion of Reset.
(0H, 1H, 2H is the MAC)
Haven't been through the Realtek code yet.
But I suspect it's something similar.
More information about the U-Boot