Guglielmi,
ARISC driver is a pair of 2 cooperating programs: arisc-hal is a portion that works with Linuxcnc as a real-time task, then You have arisc-fw that is a program for a separate RISC core in a Allwinner chip (I don't know if MX_Master implemented it for any other chip). RISC core works without operation system, and it's task is high-speed sampling/setting GPIO lines. That's why You only need ~1ms servo thread in Linuxcnc, no base thread.
Look at
github.com/allwincnc/linuxcnc/tree/master/src/hal/drivers/arisc
github.com/allwincnc/fw
First is the source for HAL portion, second is firmware for RISC core (You need different compiler for that one).
WiringPi/WiringOP access GPIO lines with normal operation system, so You need a very fast real-time base-thread in Linuxcnc, I think that this has already been done.