Setup Linux Toolchain from Scratch¶
The 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 Standard Setup of Toolchain for Linux.
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).
Install Prerequisites¶
To compile with ESP-IDF you need to get the following packages:
CentOS 7:
sudo yum -y update && sudo yum install git wget ncurses-devel flex bison gperf python3 python3-pip cmake ninja-build ccache dfu-util libusbx
CentOS 7 is still supported but CentOS version 8 is recommended for a better user experience.
Ubuntu and Debian:
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
Arch:
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
Note
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”.
Compile the Toolchain from Source¶
Install dependencies:
CentOS 7:
sudo yum install gawk gperf grep gettext ncurses-devel python3 python3-devel automake bison flex texinfo help2man libtool make
Ubuntu pre-16.04:
sudo apt-get install gawk gperf grep gettext libncurses-dev python python-dev automake bison flex texinfo help2man libtool make
Ubuntu 16.04 or newer:
sudo apt-get install gawk gperf grep gettext python python-dev automake bison flex texinfo help2man libtool libtool-bin make
Debian 9:
sudo apt-get install gawk gperf grep gettext libncurses-dev python python-dev automake bison flex texinfo help2man libtool libtool-bin make
Arch:
sudo pacman -Sy --needed python-pip
Create the working directory and go into it:
mkdir -p ~/esp
cd ~/esp
Download crosstool-NG and build it:
git clone https://github.com/espressif/crosstool-NG.git
cd crosstool-NG
git checkout esp-2021r2
git submodule update --init
./bootstrap && ./configure --enable-local && make
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.
Build the toolchain:
./ct-ng riscv32-esp-elf
./ct-ng build
chmod -R u+w builds/riscv32-esp-elf
Toolchain will be built in ~/esp/crosstool-NG/builds/riscv32-esp-elf.
Add Toolchain to PATH¶
The custom toolchain needs to be copied to a binary directory and added to the PATH. Choose a directory, for example ~/esp/riscv32-esp-elf/, and copy the build output to this directory.
To use it, you will need to update your PATH environment variable in ~/.profile file. To make riscv32-esp-elf available for all terminal sessions, add the following line to your ~/.profile file:
export PATH="$HOME/esp/riscv32-esp-elf/bin:$PATH"
Note
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.
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 beginning of displayed string:
$ printenv PATH
/home/user-name/esp/riscv32-esp-elf/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
Instead of /home/user-name there should be a home path specific to your installation.
Next Steps¶
To carry on with development environment setup, proceed to Step 2. Get ESP-IDF.