I had this issue when trying to upgrade from Arducopter 3.4.6 on Jessie. So I backed up the image and flashed a brand new stretch image emlid-raspbian-20180525.
All I have done since then is set up internet access with:
sudo nano /boot/wpa_supplicant.conf
and then do:
sudo raspi-config --expand-rootfs
sudo apt-get update && sudo apt-get dist-upgrade
rebooting after these steps
Then, I ran:
sudo emlidtool ardupilot
Got the RCIO upgrade prompt, hit yes, then rebooted.
Now, when I try to run sudo emlidtool ardupilot I get this error:
"No such file or directory: ‘/sys/kernel/rcio/status/crc’
sudo emlidtool rcio restart results in the same
sudo emlidtool rcio check or update gives
“Please verify that rcio_spi is loaded and /sys/kernel/rcio/status/crc exists”
I am not sure what to do, cannot find same issue anywhere else. When I browse directories kernel/rcio doesn’t even exist.