How to install Env Tool with QEMU simulator in Ubuntu

wget https://raw.githubusercontent.com/RT-Thread/env/master/install_ubuntu.sh
chmod 777 install_ubuntu.sh
./install_ubuntu.sh

对于中国大陆用户，请使用以下命令

wget https://gitee.com/RT-Thread-Mirror/env/raw/master/install_ubuntu.sh
chmod 777 install_ubuntu.sh
./install_ubuntu.sh --gitee

PLAN A: Whenever start the ubuntu system, you need to type command source ~/.env/env.sh to activate the environment variables.

or PLAN B: open ~/.bashrc file, and attach the command source ~/.env/env.sh at the end of the file. It will be automatically executed when you log in the ubuntu, and you don't need to execute that command any more.

Please see: https://github.com/RT-Thread/rt-thread/blob/master/documentation/env/env.md#bsp-configuration-menuconfig