Booting FreeBSD kernels
In order to boot FreeBSD you must have an up-to-date version of the Linux/xbox BIOS, called Cromwell (failure will result in your kernel crashing immediately after loading). A Cromwell with FreeBSD UFS patches (this will make it able to load a kernel directly from an UFS file system) is available in the ports tree at /usr/ports/sysutils/cromwell; it can be flashed to the EEPROM using the /usr/ports/sysutils/raincoat port (as long as your Xbox is below version 1.6).
Note: Several Xbox drives are known to reject certain types of media. Should you experience random hangs, panics or corruption during installation, try a different known-working DVD/CD-ROM.
Installing on the hard drive
You can do an installation using the Live CD’s, but you will need to do everything manually. It is suggested to prepare your disk using an FreeBSD/i386 installation and set up the /boot/xboxlinux.cfg configuration file yourself, so Cromwell can determine which kernel to load.