[U-Boot-Users] bootloader MAC

Wolfgang Denk wd at denx.de
Fri Jun 9 18:56:26 CEST 2006

In message <200606090923.18523.ngustavson at emacinc.com> you wrote:
> On Friday 09 June 2006 2:44 am, Wolfgang Denk wrote:
> > You obviously know these things better than me, so I better shut up.
> I've got some hardware experience but you certainly are far more experienced 
> with bootloaders than me. 

Maybe not only bootloaders.

You claim things which you obviously never checked.

For example, you wrote:

> It's a common practice among ethernet controllers, such as the Realtek 8139 
> and the Intel 82559 to have the MAC address automatically load from the 
> EEPROM upon reset with no intervention from any sort of driver. 

You obviouly never bothered to spend a thought on *who* reads the MAC
address from EEPROM on such  systems?  These  cards  don't  have  any
on-board BIOS or so which would do this.

You never bothered to check for example  "drivers/rtl8139.c"  in  the
U-Boot sources or "drivers/net/8139*.c" in the Linux kernel tree.

You never bothered to check for example  "drivers/eepro100.c"   in  the
U-Boot sources or "drivers/net/e100.c"  in the Linux kernel tree.

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?

But you write:

> There isn't really anything incorrect about expecting the MAC to be
> valid upon loading the OS,It's typical of the industry.

Maybe you should go and read a bit of driver code from some operating
systems, before claiming to know what these do or don't do.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
If there was anything that depressed him more than his own  cynicism,
it was that quite often it still wasn't as cynical as real life.
                                 - Terry Pratchett, _Guards! Guards!_

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