Hey guys, I built ArchLinux image with working on-board wifi (no bluetooth now, but i'm working on it). I hope this instruction will help to someone else.
Download base archlinuxarm image for armv7h from here
Create one ext4 partition on sd card (no separate /boot needed) and extract image with bsdtar -xpf ArchLinuxARM-armv7-latest.tar.gz -C path
Download boot.scr and save it as /boot/boot.scr
Download nvram and save it as /usr/lib/firmware/brcm/brcmfmac43362-sdio.txt
Download dtb and save it as /boot/dtbs/sun6i-a31s-bananapi-m2.dtb
Download u-boot and flash it with following command: dd if=u-boot-sunxi-with-spl.bin of=/dev/mmc*** bs=1024 seek=8
umount & sync & eject. That's end, you should got working linux with working wifi.