The Giant Board uses u-boot overlays to load the device configurations at boot. This makes it easy to enable and disable hardware being used with Linux drivers instead of CircuitPython.
The easiest way to change the overlay options its to edit the uEnv.txt text file using this command
sudo nano /boot/uboot/uEnv.txt
When the file opens, it should look like this
Make sure to uncomment the line
enable_uboot_overlays=1 this allows overlays to load on boot:
# enable u-boot overlays enable_uboot_overlays=1
You then want to uncomment the line containing GB-24LCD-FEATHERWING.dtbo like the image below.
After that you can exit and save using ctrl + x and hit Y to accept to write the file and power off your device using the command
sudo shutdown -h now
Once the device is fully powered off, you can now insert the Giant Board into the TFT FeatherWing and re-power the device. You should see the login screen after a short while if everything is setup correctly. It should look something like this