Download files in RUN mode

Hi,

I want to download a selected binary file to My RCM4100 using serial connection and need to store it permenetly in the Flash memory. so when not connected to the serial port , that .bin file programme should execute. Can anybody help me in this case?
what is the way to write to flash memory when in run mode?will that written things will available even without power ( without battery back up also)?
:confused: