relative tftp path for embedded script, pxelinux.0 behaviour

[pojntfx]

An old thread, but as I still stumbled upon this issue in 2021: It is possible to use i.e. the `root-path` (17) DHCP option to find the absolute path from which iPXE was loaded, even if it is from an embedded script; I've created a repo which shows this in action: https://github.com/pojntfx/ipxe-binaries

Code:

#!ipxe

dhcp
chain tftp://${root-path}:69/config.ipxe