I built and customized a linux based embedded OS for a custom hardware board that was built on Allwinner A20 processor.
I integrated a touch screen interface and configured drivers for it. The kernel was also cross-compiled for this specific architecture.
Bootloader used was u-boot and the Filesystem was built using Yocto.
Login manager used graphical user interface was lxdm.
I learnt how to write and build custom meta layers and recipes for custom packages in yocto.
The final built OS image was ported on an sd card.