Any Recommendation on creating a custom iso from installed OS

[knatesan]

I made some progress today ..
after i add netboot options like below its found the mnt point.
but now its failing in the network confi..


below is my bootloader.cfg:
set root-path /tftpboot/ipxe/nfsshare
set nfs-server 192.168.13.5
kernel http://192.168.13.5/nfsshare/casper/vmlinuz
initrd http://192.168.13.5/nfsshare/casper/initrd.gz
imgargs vmlinuz root=/dev/nfs boot=casper netboot=nfs nfsroot= "http://192.168.13.5/nfsshare/"

Output:
its keep looking in the network config,[please refer the attached screenshot]

please let me know if i am missing something?
how do i pass the nfsroot arg?
Appreciate your contiguous response.