Implementing a FS: some help required

[Artem 'Zazoobr' Ignatjev]

Hello

I've recently came accross an issue with solaris/x86 hard, which was
damaged so much, that it caused native solaris fsck dump a core. Since
there was some important data on that hard, I started playing with that
hard. It's said that Solaris uses UFS derived from 4.2BSD, and after a
while I was able to mount it.
I've found their disklabel structure and now I want to make BSD
recognize it, so that it will automatically detect layout of their
partitions.
Where can i find docs on adding implementations of others filesystems
into  kernel?