$ wget https://releases.linaro.org/components/toolchain/binaries/6.3-2017.02/aarch64-linux-gnu/gcc-linaro-6.3.1-2017.02-x86_64_aarch64-linux-gnu.tar.xz -P /tmp
$ tar xJvf /tmp/gcc-linaro-6.3.1-2017.02-x86_64_aarch64-linux-gnu.tar.xz -C /opt/toolchains