The env_install_toolchain.sh is a shell script to install this toolchain.
We can use
source ./env_install_toolchain.sh /opt/toolchain
command line to install toolchain in /opt/toolchain.
Or we can use
source ./env_install_toolchain.sh dirname
command line to install toolchain in the "dirname" which you Specified.
For now, we can use toolchain in everywhere.