I think the main bit of the puzzle that's missing for klibc integration
at this point, other than the kbuild bits, is a kinit that's a true
replacement for prepare_namespace() and everything south of it in
init/main.c. This means that it should be able to replace all that code
and any code that's removed from it, totalling about 6000 lines of
kernel code.
The kinit that's currently in the klibc tree is missing quite a bit of
functionality, such as proper handling of initrd (which the kernel dumps
as a file in the rootfs.)
So, it's quite a bit of code, but it's not particularly difficult code.
It's just a mere matter of (somewhat intelligent) typing :)
I'm hoping to have a fully backwards-compatible kinit in a few weeks.
-hpa