This document directs how to get there, but it is for the old Sun website. http://download.oracle.com/docs/cd/E19569-01/820-1188-12/core_ilom_firmware.html#50413605_67571
Download the flash image .ima file using these steps:
Naviage to http://www.sun.com/download/
Locate the Hardware Drivers section.
Click the X64 Servers and Workstations.
Click the link for the Integrated Lights Out Manager (ILOM) Server software release version that you want.
Under the new Oracle site, how do I get to the X4100 firmware updates?