I. Setup esp-open-sdk a. Requirements and Dependencies(Debian/Ubuntu) sudo apt-get install make unrar-free autoconf automake libtool gcc g++ gperf \ flex bison texinfo gawk ncurses-dev libexpat-dev python-dev python python-serial \ sed git unzip bash help2man wget bzip2 sudo apt-get install libtool-bin b. Building git clone --recursive https://github.com/pfalcon/esp-open-sdk.git cd esp-open-sdk make c. Using the toolchain sudo echo " export PATH=\$PATH:\%HOME/@localPath/esp-open-sdk/xtensa-lx106-elf/bin " >> ~ /.bashrc example: sudo echo "export PATH=\$PATH:\$HOME/ ws/esp8266/SDK/esp-open-sdk/xtensa-lx106-elf/bin " >> ~/.bashrc source ~/.bashrc Test compiler: xtensa-esp32-elf-gcc -v d. ...