I needed to support PXE booting on my home network. I use OpenWRT as my main router and DHCP server and it took me a bit of searching how to configure the BOOTP next server to redirect local clients to my Arch TFTP/NFS server for booting, so I'm placing the config here to help others who might be looking to do the same thing.
It's worth noting that this isn't a guide on setting up PXE booting completely on an OpenWRT, you'll need another system that is running a configured TFTP server. I'll write up how I setup my Arch box as a TFTP server at a later date.
The config itself was very simple; You just need to add a couple lines to
/etc/config/dhcp. You'll want to replace 10.0.0.45 with whatever your local
TFTP server is.
config boot linux option filename 'pxelinux.0' option serveraddress '10.0.0.45' option servername 'Arch-Pixie'
pxelinux.0 is from syslinux, and the servername has no technical
meaning, but it provides nice information to the clients. In this case I've
used the name of my Arch linux server that I'll be booting off of.
Hope this helps someone out. Cheers!