I want to know how execute a script automatically after startup, im using userspace
Perhaps you can execute the script you want in the /customer/demo.sh file.
i tried add a executable sh, if i execute demo.sh it’s fine, when i reboot, the instruction set that i wrote disappear 
thanks
Try adding the following instructions to the demo.sh file to test?
echo "hello world" >> /customer/test.log
Advised to run the sync command before restarting the device.
it works, thanks 