How do I disable onboard audio on a Raspberry pi 5

Hello Everyone!

I have an RPI 5 with a HiFiBerry DAC+ ADC PRO. According to the HiFiBerry website the RPI 5 is supported, but until they develop new drivers the onboard audio on the Pi needs to be disabled. Probably a dumb question, but how do I disable onboard audio in LibreELEC running in a RPI 5?

Thanks in advance!

Update:

First. I was mistaken. I have a HiFiBerry DAC 2 pro, not the DAC+. There are no specific overly files for this board in /flash/overlays. However there is a hifiberry-dac.dtbo file. When I add dtoverlay=hifiberry-dac to the config.txt file the board shows as an option in LibreELEC, but I still get no sound. If I try any of the dac+ overlays the hifiberry doesn't show as an option. I think I'm hung up on disabling the onboard audio on the Pi5

Back to the Pi4 for now...

Have a wonderful New Year!

I nailed it!

I'll post the solution here for posterity. It's a mix of LiibreELEC documentation along with what I found on the HiFiBerry site. I'm running the 12.0 nightly build.

# First, make the /flash file system read/write
mount -o remount,rw /flash

# Add the following lines to config.txt (note: I'm not sure if 'dtparam=audio=off' is required at this point, but I left it there.)
force_eeprom_read=0
dtoverlay=
dtparam=audio=off
dtoverlay=vc4-kms-v3d,noaudio
dtoverlay=hifiberry-dacplusadc
# In this case the correct overlay is "hifiberry-dacplusadc." Your specific overlay file can be found in /flash/overlays

# Save config.txt and make the /flash filesystem read only.
mount -o remount,ro /flash

Reboot. SSH into your installation and enter 'aplay -l'
You should now see your sound board available.