There is no community support (yet) for kernel 3.4.x which means you need to use previously mentioned (Official) Allwinner SDK. Current result is poor so I don't want to build images using that kernel. Way too much bugs for a single person or a small group to fix and support.
For mainline kernel (kernel.org) there are some patches for basic functionality but haven't got time to test. https://patchwork.ozlabs.org/project/devicetree-bindings/list/?submitter=65627