Then you're not going to get network rootfs. The functionality has been pretty much removed from the later on 2.6 kernels. I know this because we had issues trying to use the vanilla 2.6 kernels with our ATCA stuff under Montavista Linux- they've been porting it back in for the last 2-3 years now to their kernels. You have to have the embedded initramfs, or supply one with your arbitrary kernel, do your network mount and pivotroot into it.
What do you mean by that? Why can't I load ramfs from network while booting?
At my job I'm currently using several x86 and some older PPC servers with 2.6 kernel. They all can boot from network and have their rootfs on a NAS.
Though it is crucial to specify the version of NFS used, like in
kernel.org's howto is your friend http://www.kernel.org/pub/linu.....-howto.txt