I would to get a boot daemon service.
My android 6 device is rooted and I installed busybox pack on it. After remount my /system partition in read/write, I make /system/etc/init.d directory and I put my shell script inside. I rebooted my android device and the script didn't start alone. I checked the executable permission as well.
I browse the web around the question and I should modify my /init.rc file trough modify the boot.img file and this is a few complicate and init.rc seems target one file not a directory.
Is there an other procedure?
Thank for your help.