I’ve got a little program that uses an spi hat that I set to start running from rc.local.
It was all running fine under Jessie, but I’ve upgraded to Stretch and now it appears rc.local is being called before the /dev/spidev.* device files have been created, so the application fails to start. Once the login prompt appears I can start the app manually and the spi system works fine, so it just seams like a matter of timing and waiting for the spi dev files to be created.
I’m trying to work out what part of the boot process is creating the files in dev, so I can setup a systemd service that waits for them before starting my app. I have a working service that calls the app, but it’s having the same issue as rc.local and starting too early.
Anyone have any ideas or pointers as to where I should look?