Oracle sun X4-8 Installation Manual page 29

Boot Mode
For more details on UEFI BIOS, see the Oracle x86 Administration Guide for X4 Series Servers
at:
http://www.oracle.com/goto/x86AdminDiag/docs
Description
Note - Once you choose a boot mode and install an operating system, if you
reboot the server and select a different boot mode, the installed image is not
accessible and cannot be used.
UEFI BIOS
Managing Your Server 29