Hi AC,
I haven't seen an NFS root, in this website http://ccc.ntu.edu.tw/index.php/en/news/40 I noticed some Linux images for the Galileo board, perhaps you can verify if one of them works for your project or you can try to customize your own image. Here some documents you can use to create your image.
Intel® BSP build guide
https://communities.intel.com/docs/DOC-21882
Also I saw this post https://communities.intel.com/thread/45350 some mentioned a NFS root image, not sure if you could check if he have some additional information about it.
Additional information.
http://elinux.org/images/9/93/Elce11_stewart.pdf
LDiego.
