Boot kernel using tftp

At the ubuntu host, install the tftp server:

sudo apt-get install tftpd

Add these lines to /etc/inetd.conf :

#:BOOT: TFTP service is provided primarily for booting.  Most sites
#       run this only on machines acting as "boot servers."
tftp            dgram   udp     wait    nobody  /usr/sbin/tcpd  /usr/sbin/in.tftpd /srv/tftp

Place the kernel uImage at /srv/tftp.

At the device, setup the correct ip address and boot parameters:

# device ip:
setenv ipaddr "192.168.0.11"
setenv netmask "255.255.255.0"
setenv gatewayip "192.168.0.1"

# tftp server ip:
setenv serverip "192.168.0.24"

# load kernel from tftp server
setenv bootcmd "tftpboot 0xc0008000 uImage ; bootm 0xc0008000"

# sample bootargs to use root on NFS:
setenv bootargs "console=ttySAC0,115200 root=/dev/nfs nfsroot=192.168.0.24:/srv/rootfs/ok6410 ip=dhcp rw"