$ sudo tar -xvf gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu.tar.xz -C /opt/gcc-arm
$ export PATH=/opt/gcc-arm/bin:$PATH
$ sudo vim /etc/profile
export PATH=/opt/gcc-arm/bin:$PATH
source /etc/profile
aarch64-none-linux-gnu-gcc --version
aarch64-none-linux-gnu-gcc (GNU Toolchain for the A-profile Architecture) 9.2.1 20191203
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.