Issues configuring the network interafce on a 8260 board with multiple eth ports

Wolfgang Denk wd at
Wed Feb 4 09:45:23 EST 2004

In message <DEF39A0710293E489D45B10E06645CBD02842EEF at> you wrote:
> I am trying to bring up a second network interface, on a MPC8260 based custom board

You have to decide if you want to use manual IP configuration, or the
kernel's IP autoconfiguration, or  a  mix  of  both.  Note  that  the
kernel's  IP  autoconfiguration  seems  to be capable of handling ONE
interface only.

> I was also looking for details/examples on the kernel cmdline. All
> I could find was a brief reference on the kernel folder
> Documentation/kernel-parameters.txt. Does anybody know of good
> reference for selecting kernel parameters.

See also Documentation/nfsroot.txt for  documentation  of  the  "ip="
boot argument.

> Find below the boot-up sequence that I get when I have both FCC1 and FCC2 eth interfaces enabled.

Please explain EXACTLY what you want to do.  I  _guess_  (but  I  may
guess  wrong)  that  you  will only need one interface enabled by the
kernel's autoconfig mechanism.

> Kernel command line: root=/dev/ram rw ip= mem=32M console=ttyS3,115200 ramdisk_size=8192k

If you check with Documentation/nfsroot.txt, you will note  that  the
empty  string  between  the two colons in "voip_lnx_joao::off" is the
"<device>" part of the IP parameters. You don't specify WHICH of your
two interfaces you want to configure. In the result you get:

> IP-Config: Incomplete network configuration information.
> IP-Config: Downing eth0
> IP-Config: Downing eth1

Don't be surprised - this is what you asked for.

Assume you want to use the kernel's IP  autoconfiguration  for  eth0,
then   you   will  have  to  pass  the  kernel  a  boot  argument  of
"...voip_lnx_joao:eth0:off". The eth0 will be properly configured and
up and running  when  your  applications  start.  You  can  then  use
"ifconfig"  to  (manually)  configure  the second ethernet interface,

Best regards,

Wolfgang Denk

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