Hi,
I just port volumio to a RK3188 based TV stick, name MK802IV.
While working on a old kernel version 3.0.36, there is no overlayfs an squashfs support. The whole file system is install in internal nand flash.
Here is the code :
https://github.com/trlsmax/Build
and here is the working image :
http://tinyastro.org/upfiles/Volumio2.0-2017-11-21-rk3188.img
after download the image, download rk3188.tar.xz file from :
https://github.com/trlsmax/platform-rk3188
extract the files inside rk3188.tar.xz , there are tools to download the image into the TV stick.
on linux use the upgrade_tool :
sudo ./upgrade_tool uf image_path
on windows use the RKBathTool