to install xserver:

1. Resize your root partition first
#resize2fs /dev/nandb

2. Upgrading packages
#pacman -Syu

3. Installing packages we need
#pacman pkg-config xorg-server-devel libtool automake lxde git ... (lots of packages)

3. Setup Xorg 
http://sigpipe.me/?p=10


Tips:
1. We need to modify sunxi-mali/Makefile.config when compiling sunxi-mali
add
"
else ifeq ($(dumpmachine),arm7l-unknown-linux-gnueabihf)
  ABI = armhf
"