Jetson nano with emmc. how can i use 40 gpio by c++

i use Nano module with emmc whitch is not supported by jetson-io.py to configurate 40 pins gGPIO.how can i use GPIO by c++. I use GPIO to control LED and Matrix keyboard.
I would have implemented a similar process with the official B01, using an SD card at the time.
Specific information is as follows:
BOARD编码模式
LED:15 16 18 19 21 22 23 24 26 38 40
Matrix keyboard.:7 11 12 13 29 33 35 37

hello xinzhenren,

please examine the gpio number and controlling it through driver side.
you may access GPIOs via “gpio” device labels, /sys/kernel/debug/gpio. or, you may also use the gpiofind utility for checking the gpio number,
for example,

# gpiofind SPI0_CS0
gpiochip0 19