http://groups.google.com/group/eternity-firmware/files
Q: What does it do?
A: It allows you to edit the metadata associated with various firmware
image files, Such as the phone model it was intended for, The address
it should be flashed to and even what kind of file it is
What it does not do:
Allow you to add or remove files from FactoryFS.ffs
Allow you to modify the resources.
No you can't boot linux with it.
:P