cannot install FreeBSD 12.0 Xen 4.12.1 on Intel Core i7 CPU 930

[Stefan Parvu]

> Can you please provide the full boot log? I'm afraid that I'm not able
> to provide any suggestions without knowing what went wrong.

In BIOS everything regarding virtualization is turned ON.

How can I provide the full boot log if my machine is rebooting itself … 
and have no access to the files? Im not able to control how can I boot again.
I usually need to reinstall everything from scratch. 

Is there any way to configure the boot loader and boot with or without Xen kernel ?

Many thanks,
Stefan