1) Put this file:
     http://www.playstation.com/ps3-openplatform/data/otheros.self
   on media in dir
     /PS3/otheros/otheros.self

2) Put the "otheros.bld" file from the Sony ADDON cd:
     CELL-Linux-CL_20061110-ADDON.iso
   on media in dir
     /PS3/otheros/otheros.bld