I use a Raspberry Pi 3 to create the uCore image for the Allwinner now as it is armv7 compatible, but the uCore image format is different than in piCore. But since Raspberry Pi is already covered as a Tinycore port, I don't offer it here in the dCore form. And since the Allwinner dCore is only available now for Debian Wheezy it is kind of deprecated anyway.