Address 0x44000000 is not available for boards with 1Gb RAM, so it was causing a boot error as described here:
https://forum.armbian.com/topic/5771-rock64-nightly-image/?do=findComment&comment=53150
A lower address 0x39000000 works and doesn't seem to cause any other problem.
I cannot test it in boards with more than 1Gb RAM so, even though I see no reason why it should not be compatible, it is safer to test just in case.