System requirements

Both the overlay and the bridge were tested in the following environment:

• Raspberry Pi OS Lite
• Release date: October 10th 2023
• Last updated: March 15th 2024
• System: 64-bit
• Kernel version: 6.6
• Debian version: 12 (bookworm)
• Raspberry Pi: models 3B/B+, 4B and 5B

Build instructions

1. Install Kernel Headers apt install raspberrypi-kernel-headers
2. Compile the overlay and kernel module make
3. Install the overlay and kernel module make install
4. Manually add the overlay to /boot/firmware/config.txt dtoverlay=vc4-kms-dpi-custom
5. Manually add the kernel module to /etc/modules-load.d/modules.conf rpi-dpidac
6. Optionally you can modify /boot/firmware/timings.txt file with your custom timings

Misc

• Check if kernel module is loaded lsmod | grep rpi_dpidac
• Display module info modinfo rpi-dpidac
• Load module manually modprobe rpi-dpidac or insmod /usr/lib/modules/$(uname -r)/extra/rpi-dpidac.ko.xz
• Unload module manually modprobe -r rpi-dpidac
• Get kernel bridge message status less /var/log/messages | grep RPI-DPIDAC or dmesg | grep RPI-DPIDAC