Hi Adrian,
thanks for your response. I have now been able to get the HDMI output up with the ADI code on GitHub. Once I work through the differences I will post a further message with the details of what the differences are. I didn't want to put up a reply until I could explain the answer to others who might read this. Could I make a suggestion that the devicetree.dtb file is put in the hdl project directories. The reason why I suggest this is it allows you to build your boot.bin file and know whether it is working before you deal with the Linux issues.
regards,
Greg