This kernel is outdated for PB618, I try to make it work for it.
It can be compiled, touchscreen proprietary module does not work. I added sun8iw10p1-618.dts and 618_defconfig extracted from PB618, dts seems to be unused.
gcc-linaro-arm-linux-gnueabihf-4.9-2014.09
It additionally requires lib32-gcc-libs lib32-zlib lib32-glibc on Arch Linux.
stock kernel is built by it, although, we can use slightly newer 64bit version:
gcc-linaro-4.9-2015.05-x86_64_arm-linux-gnueabihf.tar.xz
sudo pacman -S bc inetutils gcc-libs mercurial uboot-tools
make ARCH=arm CROSS_COMPILE=*CHANGE_PATH*/arm-linux-gnueabihf- -j$(nproc) 618_defconfig
make ARCH=arm CROSS_COMPILE=*CHANGE_PATH*/arm-linux-gnueabihf- -j$(nproc) uImage
There should be uImage, zImage and Image in arch/arm/boot/. You can boot uImage from preinstalled U-Boot(see linux-sunxi wiki to enter into it's shell/monitor).