[U-Boot-Users] [PATCH] lan91c96 driver MAC address detection

Woodruff, Richard r-woodruff2 at ti.com
Tue May 4 19:19:22 CEST 2004


You might say that the u-boot 'bootp command implementation', which
utilizes the bootp protocol, will initialize the ether driver which in
turn causes mac address initialization.  All u-boot network 'commands'
do this as their protocols require that the mac is setup as a
precondition to their use.

I have to admit the first time I read the post I was confused to the


Richard W.

> -----Original Message-----
> From: u-boot-users-admin at lists.sourceforge.net [mailto:u-boot-users-
> admin at lists.sourceforge.net] On Behalf Of Wolfgang Denk
> Sent: Tuesday, May 04, 2004 12:02 PM
> To: Dave Peverley
> Cc: u-boot-users at lists.sourceforge.net
> Subject: Re: [U-Boot-Users] [PATCH] lan91c96 driver MAC address
> In message <40978D65.7030805 at mpc-data.co.uk> you wrote:
> >
> > > You cannot use BOOTP (nor ony  other  network  related  protocol)
> > > detect a MAC address!!!
> > I think that either we operate on utterly different
> > or theres some kind of language barrier issue here!
> BOOTP is a well-defined protocol which is  based  on  the  assumption
> that  you  have  a  network  interface  that  can be used to send and
> receive packets. To do so, the interface must be  initialized.  BOOTP
> does  in  NO  WAY  work if your interface does not have a MAC address
> set. Especially, it does NOT retrieve the MAC address from anywhere.
> > If you issue a 'bootp' command to u-boot via its interface as I
> > the following call sequence happens if you're using the lan91c96
> > patch) or smc91111 ethernet devices :
> >
> >    do_bootp()                     [cmd_net.c]
> >     netboot_common()              [cmd_net.c]
> >      NetLoop()                    [net.c]
> >       eth_init()                  [lan91c96.c]
> Stop here. eth_init() performs the  initialization  of  the  ethernet
> interface,  if  this  did  not  happen before, because an initialized
> ethernet interface is a precondition to use BOOTP.
> > So in practical use, issuing a bootp detects the mac address of the
> > adapter.
> No, no, no. This is plainly wrong.
> > Well, the following network related protocol calls :
> >   do_tftpb()
> >   do_rarpb()
> >   do_dhcp()
> >   do_nfs()
> > all call netboot_common() so will in effect detect the MAC address
> > well ;-)
> None of these protocols has ato do  anything  with  setting  the  MAC
> address. Please don't mix things up.
> You could as well claim that bootp sets the baudrate  of  the  serial
> console,  because  to  run  bootp  you must execute an initialization
> sequence which includes the serial port, thus setting the baudrate.
> Wolfgang Denk
> --
> Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
> Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
> Oh, that sound of male ego.  You travel halfway across the galaxy and
> it's still the same song.
> 	-- Eve McHuron, "Mudd's Women", stardate 1330.1
> -------------------------------------------------------
> This SF.Net email is sponsored by: Oracle 10g
> Get certified on the hottest thing ever to hit the market... Oracle
> Take an Oracle 10g class now, and we'll give you the exam FREE.
> http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click
> _______________________________________________
> U-Boot-Users mailing list
> U-Boot-Users at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/u-boot-users

More information about the U-Boot mailing list