Comment # 7 on bug 1199909 from Matthias Brugger

(In reply to Peng Fan from comment #6)
> seems usb function is broken in this build, did you enable xhci_hcd
> xhci_plat_hcd?
> 

they should be part of the installer. don't they get probed? Can you try to
start a shell, either by entering expert menu in the installer or by passing
startshell=1 in grub.

> The full build has eMMC detected.
> 

Happy that this works now.

> For network, there is somthing wrong in my device tree, after fix, I could
> see eth0 light blink and eth0 detected, but ping/dhcpd not able to return
> success, still need check.