Originally available from the a1g3dev mailing list:
https://lists.samfundet.no/mailman/faq/a1g3dev/Rompuller.pdf

Many of the original AmigaOne SE and XE boards shipped with a write-
protected Flash ROM that could not be updated. Users needed to replace 
the ROM with a write-enabled one in order to be able to install the
U-Boot updates that would allow OS4 to boot. These instructions from 
2003 show how to swap out the chip with simple tools.