@kgosset Well I’m a strong believer of you learn more from your mistakes than your successes, so I’ll only give you a push in a direction.
So lets take a hacker’s approach to this (the 1980s definition of a hacker not the 2000s blackhat).
I already gave you one clue. Point your browser to http://<fog_server_ip>/fog/service/ipxe/boot.php?mac=00:00:00:00:00:00 That will display the FOG iPXE menu as the FOG Project developer (wizards) have create. I figure they know a lot more than I do about the iPXE menu commands and structure. So copy the contents of that menu save it into a text file (save yourself some grief by using notepad++ and not ms windows notepad to edit this file). Save the file as a UNIX script file and name it something like custommenu.ipxe. The ipxe extension is important.
Now you can throw out a lot in this menu, but look for a :Menu line label. Delete the content below (but leave :Menu) down to :bootme (leave :bootme)
Now insert this into the deleted section (between :Menu and :bootme)
NOTE: this has NOT been tested. I only dreamed it up moments ago
menu
item fog.mainmenu Return to the FOG iPXE menu
item --gap
menu --name dell-laptop Dell Laptops
item fog.dell.7400 Dell Latitude 7400
item --gap
menu --name dell-desktop Dell Desktops
item fog.dell.3060 Dell Optiplex 3060 (mini)
item --gap
menu --name utilities
item fog.mdt Boot into MDT
choose --default fog.mainmenu --timeout 10000 target && goto ${target}
:fog.mainmenu
params
param mac0 ${net0/mac}
param arch ${arch}
param platform ${platform}
param product ${product}
param manufacturer ${product}
param ipxever ${version}
param filename ${filename}
param sysuuid ${uuid}
chain http://${boot-url}/service/ipxe/boot.php##params
boot || goto MENU
:fog.dell.7400
boot || goto MENU
:fog.dell.3060
boot || goto MENU
:fog.mdt
mdt.1903
kernel http://${fog-ip}/wimboot
imgfetch --name BCD http://${fog-ip}/mdt/Boot/BCD BCD
imgfetch --name boot.sdi http://${fog-ip}/mdt/Boot/boot.sdi boot.sdi
imgfetch --name boot.wim http://${fog-ip}/mdt/Sources/Boot.wim boot.wim
boot || goto MENU
Place this file on the FOG server in the /tftpboot directory.
Now you need to make a new iPXE menu entry to call this menu.
Menu Item: fog.CustomMenu
Description: Custom FOG Menu
Parameters:
chain tftp://${fog-ip}/custommenu.ipxe
boot || goto MENU
Now pxe boot a target computer. See if your menu works to go into and out of the custom menu. I’ll say this again, I did not test this menu design so there are probably bugs in it. But this is the framework. Once your menu works then we can work on filling out the menu items in your custom menu. I will show you how to get the details for the menu items.
ref:
Contents of /tftpboot/default.ipxe
https://forums.fogproject.org/topic/10944/using-fog-to-pxe-boot-into-your-favorite-installer-images
https://ipxe.org/cmd/menu