Mounting an NFS filesystem requires the loopback interface to be up

Over the last few weeks, I've been using flash drives connected to my BeagleBoard to store files for compilation; the MMC card I use for the root filesystem is too small for compiling MPlayer.  Unfortunately, the flash drive stopped working, and I can't seem to recover a single byte of what was on it.

So, I decided to mount an NFS partition instead, but most of the commands I tried after running rpcbind (the portmapper) hung until they timed out.  What I finally worked out is that the loopback interface has to be up ("ifconfig lo up") for them to work.

If I was trying to mount an NFS partition as my root partition, I would probably take the approach I used for the x86 live CD, which was to have a compressed minimal root filesystem as part of the kernel image (look into CONFIG_BLK_DEV_INITRD, CONFIG_INITRAMFS_SOURCE, etc.), which was able to bring up the appropriate interfaces (reading environment variables set in the uEnv.txt file for the NFS server, etc.).