Info regarding Index to the Main RPi Thread

The original thread was getting way long, with a lot of info spread out.
Pleas pay particular attention to the hal_gpio stuff, there is a basic 3 axis mill config that works. If you get any errors when thrying to use hal_gpio, unless the error log states "no permission" the issue is a permission error (which should not happen), otherwise it is related to the GPIO pins selected or somethng else. Mostly this occurs when a user attempts to use the SPI allocated pins without disabling the SPI interface.
What I suggest to the RPi users is to bookmark the Index thread forum.linuxcnc.org/38-general-linuxcnc-q...l-images-only#325007 for later reference . 

"unless the error log states "no permission" the issue is a permission error"

What does this mean exactly?

If the error log states "no permission", there is NOT a permission issue, correct?