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.
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Under the new Oracle site, how do I get to the X4100 firmware updates?