The Pine64 root filesystem was incorrectly created directly on the MBR
partition. This can cause the loader to get confused when loading the
kernel from this filesystem.
The loader will see this as a small partition meaning later checks to
ensure it doesn't read past the end of the disk incorrectly report a
failure. This seems to work mostly by accident with the released images
as they are smaller than the reported size, however after growfs has
run the image may no longer boot.