*************************************
Standard Setup of Toolchain for Linux
*************************************


Install Prerequisites
=====================

To compile with ESP-IDF you need to get the following packages:

- CentOS 7::

    sudo yum install git wget make ncurses-devel flex bison gperf python pyserial

- Ubuntu and Debian::

    sudo apt-get install git wget make libncurses-dev flex bison gperf python python-serial

- Arch::

    sudo pacman -S --needed gcc git make ncurses flex bison gperf python2-pyserial


Toolchain Setup
===============

ESP32 toolchain for Linux is available for download from Espressif website:

- for 64-bit Linux:

  https://dl.espressif.com/dl/xtensa-esp32-elf-linux64-1.22.0-61-gab8375a-5.2.0.tar.gz

- for 32-bit Linux:

  https://dl.espressif.com/dl/xtensa-esp32-elf-linux32-1.22.0-61-gab8375a-5.2.0.tar.gz

1.  Download this file, then extract it in ``~/esp`` directory::

        mkdir -p ~/esp
        cd ~/esp
        tar -xzf ~/Downloads/xtensa-esp32-elf-linux64-1.22.0-61-gab8375a-5.2.0.tar.gz

.. _setup-linux-toolchain-add-it-to-path:

2.  The toolchain will be extracted into ``~/esp/xtensa-esp32-elf/`` directory.

    To use it, you will need to update your ``PATH`` environment variable in ``~/.profile`` file. To make ``xtensa-esp32-elf`` available for all terminal sessions, add the following line to your ``~/.profile`` file::

        export PATH=$PATH:$HOME/esp/xtensa-esp32-elf/bin

    Alternatively, you may create an alias for the above command. This way you can get the toolchain only when you need it. To do this, add different line to your ``~/.profile`` file::

        alias get_esp32="export PATH=$PATH:$HOME/esp/xtensa-esp32-elf/bin"

    Then when you need the toolchain you can type ``get_esp32`` on the command line and the toolchain will be added to your ``PATH``.

    .. note::

        If you have ``/bin/bash`` set as login shell, and both ``.bash_profile`` and ``.profile`` exist, then update ``.bash_profile`` instead.

3.  Log off and log in back to make the ``.profile`` changes effective. Run the following command to verify if ``PATH`` is correctly set::

        printenv PATH

    You are looking for similar result containing toolchain's path at the end of displayed string::

        $ printenv PATH
        /home/user-name/bin:/home/user-name/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/home/user-name/esp/xtensa-esp32-elf/bin

    Instead of ``/home/user-name`` there should be a home path specific to your installation.


Arch Linux Users
----------------

To run the precompiled gdb (xtensa-esp32-elf-gdb) in Arch Linux requires ncurses 5, but Arch uses ncurses 6. 

Backwards compatibility libraries are available in AUR_ for native and lib32 configurations:

- https://aur.archlinux.org/packages/ncurses5-compat-libs/
- https://aur.archlinux.org/packages/lib32-ncurses5-compat-libs/

Alternatively, use crosstool-NG to compile a gdb that links against ncurses 6.


Next Steps
==========

To carry on with development environment setup, proceed to section :ref:`get-started-get-esp-idf`.


Related Documents
=================

.. toctree::
    :maxdepth: 1

    linux-setup-scratch


.. _AUR: https://wiki.archlinux.org/index.php/Arch_User_Repository
