1******************************************
2Setup Linux Toolchain from Scratch
3******************************************
4
5:link_to_translation:`zh_CN:[中文]`
6
7The following instructions are alternative to downloading binary toolchain from Espressif website. To quickly setup the binary toolchain, instead of compiling it yourself, backup and proceed to section :doc:`linux-setup`.
8
9.. note:: The reason you might need to build your own toolchain is to solve the Y2K38 problem (time_t expand to 64 bits instead of 32 bits).
10
11Install Prerequisites
12=====================
13
14To compile with ESP-IDF you need to get the following packages:
15
16- CentOS 7::
17
18    sudo yum -y update && sudo yum install git wget ncurses-devel flex bison gperf python3 python3-pip cmake ninja-build ccache dfu-util libusbx
19
20CentOS 7 is still supported but CentOS version 8 is recommended for a better user experience.
21
22- Ubuntu and Debian::
23
24    sudo apt-get install git wget libncurses-dev flex bison gperf python3 python3-pip python3-setuptools python3-serial python3-cryptography python3-future python3-pyparsing python3-pyelftools cmake ninja-build ccache libffi-dev libssl-dev dfu-util libusb-1.0-0
25
26- Arch::
27
28    sudo pacman -Sy --needed gcc git make ncurses flex bison gperf python-pyserial python-cryptography python-future python-pyparsing python-pyelftools cmake ninja ccache dfu-util libusb
29
30.. note::
31    CMake version 3.5 or newer is required for use with ESP-IDF. Older Linux distributions may require updating, enabling of a "backports" repository, or installing of a "cmake3" package rather than "cmake".
32
33Compile the Toolchain from Source
34=================================
35
36- Install dependencies:
37
38  - CentOS 7::
39
40        sudo yum install gawk gperf grep gettext ncurses-devel python3 python3-devel automake bison flex texinfo help2man libtool make
41
42  - Ubuntu pre-16.04::
43
44        sudo apt-get install gawk gperf grep gettext libncurses-dev python python-dev automake bison flex texinfo help2man libtool make
45
46  - Ubuntu 16.04 or newer::
47
48        sudo apt-get install gawk gperf grep gettext python python-dev automake bison flex texinfo help2man libtool libtool-bin make
49
50  - Debian 9::
51
52        sudo apt-get install gawk gperf grep gettext libncurses-dev python python-dev automake bison flex texinfo help2man libtool libtool-bin make
53
54  - Arch::
55
56        sudo pacman -Sy --needed python-pip
57
58Create the working directory and go into it::
59
60  mkdir -p ~/esp
61  cd ~/esp
62
63Download ``crosstool-NG`` and build it:
64
65.. include-build-file:: inc/scratch-build-code.inc
66
67.. note:: To create a toolchain with support for 64-bit time_t, you need to remove the ``--enable-newlib-long-time_t`` option from the ``crosstool-NG/samples/xtensa-esp32-elf/crosstool.config`` file in 33 and 43 lines.
68
69Build the toolchain::
70
71    ./ct-ng {IDF_TARGET_TOOLCHAIN_PREFIX}
72    ./ct-ng build
73    chmod -R u+w builds/{IDF_TARGET_TOOLCHAIN_PREFIX}
74
75Toolchain will be built in ``~/esp/crosstool-NG/builds/{IDF_TARGET_TOOLCHAIN_PREFIX}``.
76
77Add Toolchain to PATH
78=====================
79
80The custom toolchain needs to be copied to a binary directory and added to the ``PATH``. Choose a directory, for example ``~/esp/{IDF_TARGET_TOOLCHAIN_PREFIX}/``, and copy the build output to this directory.
81
82To use it, you will need to update your ``PATH`` environment variable in ``~/.profile`` file. To make ``{IDF_TARGET_TOOLCHAIN_PREFIX}`` available for all terminal sessions, add the following line to your ``~/.profile`` file::
83
84    export PATH="$HOME/esp/{IDF_TARGET_TOOLCHAIN_PREFIX}/bin:$PATH"
85
86.. note::
87
88    If you have ``/bin/bash`` set as login shell, and both ``.bash_profile`` and ``.profile`` exist, then update ``.bash_profile`` instead. In CentOS, ``alias`` should set in ``.bashrc``.
89
90Log off and log in back to make the ``.profile`` changes effective. Run the following command to verify if ``PATH`` is correctly set::
91
92    printenv PATH
93
94You are looking for similar result containing toolchain's path at the beginning of displayed string::
95
96    $ printenv PATH
97    /home/user-name/esp/{IDF_TARGET_TOOLCHAIN_PREFIX}/bin:/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
98
99Instead of ``/home/user-name`` there should be a home path specific to your installation.
100
101Next Steps
102==========
103
104To carry on with development environment setup, proceed to :ref:`get-started-get-esp-idf`.
105