Pinebook Pro: HCL image does not boot


I have tried the Pinebook Pro image from the HCL pages

First problem is that the display does not get activated and stays blank.
I have used my UART cable and could see the console boot messages that way. So the sd card actually starts ok.

At start a boot menu is shown and when I select Tumbleweed I get these messages and then nothing more happens:

 Booting a command list

Loading Linux 5.10.1-1-default ...
Loading initial ramdisk ...
EFI stub: Booting Linux Kernel...
EFI stub: EFI_RNG_PROTOCOL unavailable, KASLR will be disabled
EFI stub: Using DTB from configuration table
EFI stub: Exiting boot services and installing virtual address map...

Any ideas how to progress from here ?