enable network on FVP

[leeehui]

Hi,
I want to use network on FVP, I added "--network=nat" at the end of "~/devel/optee/build/Makefile"
but there was not ip addr when I booted into the kernel, ifconfig shows as below:
image

FVP host is ubuntu-16.04 inside VirtualBox

I am not familiar with network. is there anyone can help me ? thanks a lot!