we are considering FOUR ways to deploy FreeBSD as a XEN/PVH guest
installer on UFS or ZFS using installer
out-of-the-box VM image
bootstrap on EXT2FS like a brute from GNU/Linux dom0
bootstrap on ZFS like a brute from GNU/Linux dom0
note booting ZFS needs special kernel
12.2. FreeBSD Boot Process https://www.freebsd.org/doc/handbook/boot-introduction.html
loader – kernel bootstrapping final stage https://www.freebsd.org/cgi/man.cgi?query=loader
https://www.freebsd.org/doc/handbook/config-network-setup.html
Install FreeBSD with mfsBSD https://forums.freebsd.org/threads/install-freebsd-with-mfsbsd.14162/