I was wondering if the IP: kernel level autoconfiguration option in the "Networking options" is set for I can't boot kernel via tftp.
Need to say Y usually for diskless machines requiring network access to boot (in which case you want to say Y to "Root file system on NFS" as well), because all other machines configure the network in their startup scripts
CONFIG_NETWORK_FILESYSTEMS=y
CONFIG_NFS_FS=y
CONFIG_NFS_V2=y
CONFIG_NFS_V3=y
# CONFIG_NFS_V3_ACL is not set
CONFIG_NFS_V4=y
# CONFIG_NFS_SWAP is not set
# CONFIG_NFS_V4_1 is not set
CONFIG_ROOT_NFS=y
CONFIG_NFS_FSCACHE=y