We have a USB serial device that is not supported by the default cp210x driver. The source files need to be updated to add the VID and PID of the serial device, which can usually be done on a standard OS (Raspbian, etc.) by simply replacing the cp210x.ko module file.
I have compiled the driver in a Raspbian stretch container (build version) and that sometimes loads, but it would appear that the base balenaOS is also trying to load and there is a race condition / conflict with the containered OS trying to access the cp210x / usbserial module. No matter of how much rmmod / ins mod / modprob’ing that is done, it’s just not reliable or very repeatable.
Is there a way to have a custom module added to the base OS (which is read-only)? We have even tried to build the module with a different name to see if there is a conflict that way, but the balenaOS is still winning most of the time at grabbing the device. If the driver on the base OS could be updated, then this would not be an issue (as the container can access /dev/ttyUSB0 fine), it just does not recognise our dongle!
Any ideas on how we can progress on this, as otherwise it looks like we need to find a different solution.