customer_SVR.tar.gz => machine root filesystem code 
rootfs.tar.gz => weintek compiler SDK code 
toolchain.tar.gz => compiler arm bin file toolchain
cross_env => set up cross compile environment

for compiler set up method:
1. tar -zxvf toolchain.tar.gz -C /
2. tar -zxvf rootfs.tar.gz -C /
3. ./cross_env

Note: 
	you can change rootfs untar to anywhere but remember modify PREFIX=/ on cross_env