I created a post a few days ago about booting a MDT iso image via the ipxe boot menu. This may help you on your quest as long as you are using a svn trunk. The only thing I think I would change from this post is to move the place I stored the iso image out of the fog directory directly. In the instructions I said to place the files in /var/www/html/fog/iso , moving forward I would put them in /var/www/html/iso This location is still addressable by apache but won’t collide with anything in the fog distro.

https://forums.fogproject.org/topic/6161/debian-8-fog-trunk-pxelinux-on-ms-server-and-ms-dhcp-help/15