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IMX8 EVK DHCP not working

Question asked by Russell Coy on Jan 9, 2019
Latest reply on Jan 9, 2019 by Russell Coy

Hello,

I am trying to create an image for an i.MX8 EVK using Yocto and my own image recipe to add features and packages. I have created my own Yocto layer. The image recipe inherits the core-image and adds standard features and packages plus some customised additions. I am basing this on the NXP i.MX8 Yocto 'Morty'  BSP (fsl-yocto-L4.9.51_mx8mq-ga) i.MX_Yocto_Project_User's_Guide. Initially, I wanted to have a static IP address and so added into the image the init-ifupdown package with a customised interfaces file configured with the static IP address as per the guidance here:

Yocto Setting the Default Ethernet address and disable DHCP on boot. 

Following bitbake of the image and copying to an sd card, the eth0 interface could be brought up with the desired static IP address. I wanted the eth0 interface to be configured at start-up, so I added a recipe to enable this through systemd.

Having got this working, the requirements have now changed such that the eth0 interface needs to obtain it's IP automatically via DHCP, so I have changed the custom /etc/network/interfaces file to remove the static IP settings and revert to the default i.e.

 

# Wired or wireless interfaces

auto eth0

iface eth0 inet dhcp

 

Following a re-build of the image to incorporate the changes, the eth0 interface starts up at boot, however it does not get an ipv4 IP address via DHCP, it only gets an ipv6 address.

Bringing the interface down and then up using ifdown eth0 and ifup eth0 results in the following:

 

root@imx8mqevk:~# ifup eth0
[   34.113147] Atheros 8031 ethernet 30be0000.etherne:00: attached PHY driver [Atheros 8031 ethernet] (mii_bus:phy_addr=30be0000.etherne:00, irq=-1)
[   34.126526] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
udhcpc (v1.24.1) started
Sending discover...
Sending discover...
[   38.236282] fec 30be0000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off
[   38.243947] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
Sending discover...
No lease, forking to background

 

Is there something that I am missing from my image recipe that will allow DHCP to be run sucessfully to obtain an ipv4 IP address automatically?

 

If I create an sd card with the NXP test image (fsl-image-qt5-validation-imx-xwayland-imx8mqevk.sdcard.bz2), then this will boot with the eth0 interface correctly obtaining an ipv4 IP address. What functionality is included in this image to enable this?

 

Any advice on what the correct steps are to get DHCP to work in my custom image recipe?

 

Thanks in advance

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