TS-7250-V3 U-Boot NFS boot

Note:

The following instructions assume the NFS server is running Debian.

U-Boot's NFS support can be used to load a kernel, device tree binary, and root filesystem. The default scripts include an example NFS boot script. Because of the way U-Boot tries to infer server data, the script we use will bypass this, making it more straightforward to use an NFS root that will not be heavily dependent on a particular network configuration.

First, on the NFS server side, be sure to verify and if needed modify /etc/default/nfs-kernel-server such that the server is running NFS -V 2. The nfs-kernel-server file should resemble the following:

# Number of servers to start up
RPCNFSDCOUNT="8 --no-nfs-version 4 -V 2"

# Runtime priority of server (see nice(1))
RPCNFSDPRIORITY=0

# Options for rpc.mountd.
# If you have a port-based firewall, you might want to set up
# a fixed port here using the --port option. For more information, 
# see rpc.mountd(8) or http://wiki.debian.org/SecuringNFS
# To disable NFSv4 on the server, specify '--no-nfs-version 4' here
RPCMOUNTDOPTS="--manage-gids --no-nfs-version 4"

# Do you want to start the svcgssd daemon? It is only required for Kerberos
# exports. Valid alternatives are "yes" and "no"; the default is "no".
NEED_SVCGSSD=""

# Options for rpc.svcgssd.
RPCSVCGSSDOPTS=""

Once verified that the file /etc/default/nfs-kernel-server looks like the above, then from the U-Boot shell run the following commands:

# Set this to your NFS root path
env set nfsroot <IP ADDRESS>:/path/to/nfs/rootfs/
env save

To boot to NFS root once the server details are set:

# Boot to NFS once
run nfsboot;

# To make the NFS boot the persistent default
env set bootcmd run nfsboot;
env save

Note:

You must have NFS version 2 on your server, as it is disabled by default on new distributions. Be sure to read the U-Boot Documentation for further details U-Boot Documentation

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