btfs can be used as /init for constructing a
run-time environment before running the real init.
It supports extracting compressed (*.cgz, *.cbz2)
and uncompressed (*.co) cpios located on a
compile-defined directory (/). Also, it creates a
tmpfs filesystem as the new root, if / isn't one
already and the purpose of the initramfs isn't for
starting a system in another location (disk,
network, etc.). That will allow for the data on /
to be swapped to disk when swap devices are
activated later.
