How to configure embedded linux kernel so that the file system is visible on the host linux

I am using a powerpc, and after building and flashing the linux kernel on the device I can see the file system. But if I try to create a user or make any changes they get erased and resets to default after I reboot the device. The kernel image location is on network. I am not able to save my changes.

I am using kernel parameter as root=/dev/ram0 I have also used root=/dev/nfs nfsroot=|ip, rootdir| but it is not getting mounted.

When i type mount i get something like this rootfs on / type rootfs (rw) /dev/root on / type ext2 (rw) proc on /proc type proc (rw) which should not correct

How can I see the file system of my target on my host linux such that , I can see the target device kernel file system on my host machine and save if even I reboot the device.