[U-Boot] How to enable 2 FCC Ports while booting using CONFIG_NET_MULTI

Wolfgang Denk wd at denx.de
Tue Oct 27 09:42:53 CET 2009


Dear "Gurumurthy Gowdar",

In message <20091027063046.45327.qmail at f4mail-235-243.rediffmail.com> you wrote:
> 
> 
>          please let me know how to enable two Ethernet Ports in
> U-boot for MPC8280 at booting time. After booting i should be able to
> ping the two ports i.e. FCC1 and FCC2 only by connecting the ethernet
> cable to the repective port (FCC1 & FCC2.

You don't. You don;t do this at all.

U-Boot does not enable any peripherals "at booting time". This is a
design principle, see
http://www.denx.de/wiki/view/U-Boot/DesignPrinciples#2_Keep_it_Fast

Ethernet ininitlization is only done when U-Boot attempts to perform a
network command, and then only that single interface gets initialized
which U-Boot is going to use.

> currently i have enabled one port FCC2 as ethact port, can i change
> this depending by which port i want to ping.

Yes, you can toggle between several ports. But keep in mind that only
one of them will be active at any time, if any at all.

> i came to know about CONFIG_NET_MULTI whether this will be the
> solution for using two ports at a time.

You cannot use two ports at the same time, only one or the other. But
it is possible to switch at runtime (either automatically when a
download fails or manually by setting the "ethact" environment
variable accordingly).

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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