2. Install Tools

PC OS	Network	Permission
Ubuntu20.04	online	root

sudo apt-get install git ssh make gcc libssl-dev liblz4-tool
sudo apt-get install expect g++ patchelf chrpath gawk texinfo chrpath diffstat
sudo apt-get install binfmt-support qemuuser-static live-build bison flex fakeroot
sudo apt-get install cmake gcc-multilib g++-multilib unzip device-tree-compiler
sudo apt-get install ncurses-dev libgucharmap-2-90-dev bzip2 expat gpgv2
sudo apt-get install cpp-aarch64-linux-gnu g++-aarch64-linux-gnu
sudo apt install python2
sudo apt install python-is-python3