Igor thanks for your response. I realized that I did not specify an important detail: the system will boot from microSD, but the system is located on the first partition of a SSD (sda). With 3.4.110 kernel I had already modified the rc.local activating the green led to the "drive-activity" trigger, just to keep under control sda. But now, with version 4.4.1 in the possible options it is no longer the "drive-activity" ( ). So I was wondering if there is an alternative - the less complicated as possible, because I have no experience if I had to recompile the kernel. Thanks for the help that you can give me.
Bye
Fred