detect legacy/uefi

[silver310]

Thanks I've found a way around the DHCP server, using a proxy DHCP locally (we can't configure the main DHCP our-self).

As for the docs, I've been reading the site and the help/docs there are really minimal and don't help me.
How do i know what build options there are? what kind of build can i make, additional information about certain command, i.e: i know I can check a NICs mac address and ip, but can i check if it has a cable connected?
I've real all the help pages in the ipxe.org site and i really feel like that's just 10% of the information i need to really understand how to properly use iPXE.