I have an issue with the firmware with XPS 8920(1.0.10) firmware. Im wondering if this is by design or a bug in the firmware!
Ive setup the machine to use legacy mode with Secure boot off, I've set an admin password on the bios. and I've disabled usb boot! now if I use a uefi usb boot disk, it bypasses this security and allows me to boot from it using F12! it shows the usb boot with a * on the menu and i have to type that password to boot from that key BUT is also shows 2 uefi boot usb disks and allows me to boot from this key. I have an optiplex as well which behaves as expected and prevents booting from usb key.
I tried another suggestion using uefi boot with secure boot on and CSM off but I can still boot from a UEFI usb boot key! Am I going something wrong?