Hi folks --
I've added support for Allwinner A64 to the SUNXI kernel in -current. If you have a Pine64 or Pine64+, I've created a sysutils/u-boot-pine64 package that you can use.
The sun50i-a64 .dtb files are not yet built with the SUNXI kernel as I need to adjust the build scripts to grab them from the arm64 directory. For now you can use the dtb files from the sysutils/dtb-arm64-sun50i package.
Basic things that should work: UART, MMC, USB (EHCI/OHCI), GPIO. Note if you are using a Pine64 based board, only the bottom USB jack will work at the moment as the top one is wired to the USB OTG controller.