Recently i have been experimenting with interrupts on orange pi zero plus2-H3 trying to capture data-ready pulses from an external adc on gpio PA19.  The aim is to synchronize spi-read-data transactions with the incoming adc data-ready signal. First I tried to get it to work on legacy kernel 3.4 by adding the following section in to /boot/script.fex and compile the .fex file to .bin file using fex2bin:   [gpio_para] gpio_used = 1 gpio_num = 6 .... gpio_pin_6 = port:PA19<0><default