scriptlet feature and chainloading

[k0ldbl00d]

I want to chain-load iPXE with pre-built undionly.kpxe from http://boot.ipxe.org, but my DHCP server (Mikrotik RouterOS 6.4) does not support class-based options. My goal is to chainload iPXE and then force it to execute some script (from tftp or http) automatically without need to build it.

Can somebody explain the "scriptlet" dhcp-option to me? I've found some way how to pass it to iPXE encapsulated in DHCP option 175. In iPXE shell I type "dhcp" and then "config" and it seems that "scriptlet" option passes well. But how I can use it?

Or maybe there is another way to do this?