DHCP kernel 2.6.35

DHCP kernel 2.6.35

[ed]

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Hi,

Regards the Yocto 2.6.35 kernel I have two questions; this is for an imx28;

1) What if anything is responsible for getting a new DHCP lease (and IP 
address) after it expires or misses the initial lease? If the Ethernet 
cable is plugged in post booting up, the device never gets an address. I 
have to manually use udhcpc. How does embedded Linux cater for this?

2) Based on the imx28_evk which has eth0, eth1 and Wan0, our board only 
uses eth0. Which file do I need to edit to remove eth1 and wan0?

Thanks,

Edward.

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Re: DHCP kernel 2.6.35

[Bryan Evenson]

Edward,

> -----Original Message-----
> From: yocto-bounces@yoctoproject.org [mailto:yocto-
> bounces@yoctoproject.org] On Behalf Of ed
> Sent: Wednesday, December 09, 2015 4:06 AM
> To: yocto@yoctoproject.org
> Subject: [yocto] DHCP kernel 2.6.35
> 
> Hi,
> 
> Regards the Yocto 2.6.35 kernel I have two questions; this is for an imx28;
> 
> 1) What if anything is responsible for getting a new DHCP lease (and IP
> address) after it expires or misses the initial lease? If the Ethernet cable is
> plugged in post booting up, the device never gets an address. I have to
> manually use udhcpc. How does embedded Linux cater for this?
> 

What image is it that you are building?  The core-image-minimal image doesn't have anything included for hotplug support.  So if the Ethernet connection is not there on initial boot, you're out of luck unless you manually restart networking on the device or reboot it.  You can either use ifplugd in Busybox or connman.  Note that if you add ifplugd for Busybox that it doesn’t come with an init script and you'll have to generate one.  I found it easier to download the original ifplugd source (located here: http://0pointer.de/lennart/projects/ifplugd/#download) and make my own package from it than to use Busybox's version.  If your image has a lot more features on it than are present in core-image-minimal, connman may be more appropriate.  On my system I didn't want to pull in all the dependencies required for connman so ifplugd was more appropriate.

Regards,
Bryan

> 2) Based on the imx28_evk which has eth0, eth1 and Wan0, our board only
> uses eth0. Which file do I need to edit to remove eth1 and wan0?
> 
> Thanks,
> 
> Edward.
> 
> 
> --
> Disign Consultants
> t: +44 (0) 207 544 8486
> w: www.disignconsultants.com <http://www.disignconsultants.com>
> 
> This message and any attachment are confidential and may be privileged or
> otherwise protected from disclosure. If you are not the intended recipient,
> please telephone or email the sender and delete this message and any
> attachment from your system. If you are not the intended recipient you
> must not copy this message or attachment or disclose the contents to any
> other person.