The most import is that don’t load gc2035 & vfe_v4l2 before. So you had better remove it in /etc/modules

This is my /etc/modules

#w1-sunxi
#w1-gpio
#w1-therm
#gc2035
#vfe_v4l2
#sunxi-cir
#v4l2loopback

you may see /dev/video0, but when you reboot, it lose again

I add my scrip to /etc/rc.local

this is my /etc/rc.local

sunxi-pio -m "PG11<1><0><1><1>"
modprobe gc2035
modprobe vfe_v4l2
sleep 5
modprobe v4l2loopback devices=2
/root/vidcopy/vidcopy -w 640 -h 480 -r 30 -i /dev/video0 -o /dev/video1 -f UYVY
sleep 5
/root/vidcopy/vidcopy -w 640 -h 480 -r 30 -i /dev/video1 -o /dev/video2 -f UYVY
exit 0

Thanks my friend: “虚耗”

Source: Armbian 5.25 on OrangePI PC: The gc2035 video camera doesn’t work – Page 3 – Allwinner H2 & H3 – Armbian forum