I have got a special industrial device with linux on board. This is an individual, created by device manufacturer, truncated distribution, where the system is loaded (probably) from the saved on hard drive image. When I created a file or edit something and restart system the changes disappear.
rootfs on / type rootfs (rw)
/dev/root.old on / type ext2 (rw,relatime,errors=continue)
proc on /proc type proc (rw,relatime)
sys on /sys type sysfs (rw,relatime)
devpts on /dev/pts type devpts (rw,relatime,gid=5,mode=620)
none on /proc/bus/usb type usbfs (rw,relatime)
tmpfs on /var/ramdrive type tmpfs (rw,relatime,size=16384k)
is it possible to add files, services or something else to the system (without removing hard drive)?