This hook mounts a specified NFS path to /etc before the real init begins, primarily for diskless clients that share the same root file system but want different configurations. It's required to be used along with the "net" hook, and the last hook to run.

The hook accepts the following kernel parameter:

etc=<server-ip>:<nfs-dir>

The parameter can have these tokens:

HOSTNAME will be replaced by the hostname given by DHCP server or configured by ip= parameter.

IPV4ADDR will be replaced by the IPv4 address given by DHCP server or configured by ip= parameter.

IPV4ADDRHEX will be replaced by hexadecimal representation of the IPv4 address given by DHCP server or configured by ip= parameter.

e.g. The machine has the hostname "host0" and IP address 192.168.1.50, setting etc=192.168.1.1:/srv/etc-HOSTNAME-IPV4ADDR-IPV4ADDRHEX will make the hook attempt to mount 192.168.1.1:/srv/etc-host0-192.168.1.50-C0A80132 to /etc.