I have a webcam working fine using motion on a fairly old Pi running a version of Jessie on which I may not have done an apt-get update, upgrade recently, but trying to get it to work on another is defeating me. Both use directly connected Pi camera modules (not USB webcams). The difference seems to be that the latter hasn't got /dev/video0 created.
Both have bcm2835_v412 in /etc/modules but lsmod only shows it loaded in the one which works. In the other (the updated one), modprobe -a bcm2835_v412 reports WARNING: Module bcm2835_v412 not found.
Suggestions please? Regards - Philip