You can find the latest downloads for ROC-RK3328-CC on the product page’s Downloads section.
The first image is based on Rockchip’s Linux 4.4 LTS kernel running Ubuntu 16.04 LTS. It currently does not offer Mali 3D acceleration or hardware codec support.
Android will be coming within the next two weeks.
Once Ubuntu 18.04 is released, we will begin work on a repository for bootloaders and kernels housed in deb files so that bootstrapping images will be easy for all of our boards. Once that infrastructure is in place, non-preview images for our boards will be released. Updating bootloaders and kernels will be as simple as an apt-get.