Help in running the code on my esp32

[ayazalavi]

I am using esp idf to develop my project. I downloaded libdatachannel in esp folder so now I have 2 directories in esp folder:

1. esp-idf
2. libdatachannel

I then updated CMakeLists.txt in the root of my project and added line

set(EXTRA_COMPONENT_DIRS "$ENV{IDF_PATH}/examples/common_components/protocol_examples_common $ENV{IDF_PATH}/../libdatachannel")

now when I try to build the project I get following callstack

Executing task: ninja

[0/1] Re-running CMake...
-- Project is not inside a git repository, or git repository has no commits; will not use 'git describe' to determine PROJECT_VER.
-- Building ESP-IDF components for target esp32
CMake Error at /Users/ayaz/esp/esp-idf/tools/cmake/component.cmake:219 (message):
CMake Warning (dev) at build_properties.temp.cmake:7:

Syntax Warning in cmake code at column 51

Argument not separated from preceding token by whitespace.

Call Stack (most recent call first):

/Users/ayaz/esp/esp-idf/tools/cmake/scripts/component_get_requirements.cmake:3 (include)

This warning is for project developers. Use -Wno-dev to suppress it.

fatal: not a git repository (or any parent up to mount point /Volumes)

Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).

CMake Error at /Users/ayaz/esp/libdatachannel/CMakeLists.txt:2 (project):

project command is not scriptable

Call Stack (most recent call first):

/Users/ayaz/esp/esp-idf/tools/cmake/scripts/component_get_requirements.cmake:106 (include)
/Users/ayaz/esp/esp-idf/tools/cmake/scripts/component_get_requirements.cmake:124 (__component_get_requirements)

Call Stack (most recent call first):
/Users/ayaz/esp/esp-idf/tools/cmake/build.cmake:491 (__component_get_requirements)
/Users/ayaz/esp/esp-idf/tools/cmake/project.cmake:378 (idf_build_process)
CMakeLists.txt:10 (project)

-- Configuring incomplete, errors occurred!
See also "/Volumes/Projects/ESP-Projects/websocket/build/CMakeFiles/CMakeOutput.log".
FAILED: build.ninja
/Users/ayaz/.espressif/tools/cmake/3.20.3/CMake.app/Contents/bin/cmake --regenerate-during-build -S/Volumes/Projects/ESP-Projects/websocket -B/Volumes/Projects/ESP-Projects/websocket/build
ninja: error: rebuilding 'build.ninja': subcommand failed

• The terminal process "/bin/zsh '-c', 'ninja '" terminated with exit code: 1.

I need help in fixing this problem

EDITED:
So far I have been able to build libdatachannel for Mac and updated my CMakeLists.txt file to below:

cmake_minimum_required(VERSION 3.5)

# (Not part of the boilerplate)
# This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.
set(EXTRA_COMPONENT_DIRS $ENV{IDF_PATH}/examples/common_components/protocol_examples_common)

include($ENV{IDF_PATH}/../libdatachannel/build/LibDataChannelConfigVersion.cmake)
include($ENV{IDF_PATH}/tools/cmake/project.cmake)
project(websocket_example)

[paullouisageneau]

I'm not very familiar with ESP32, but it seems to me that the ESP32 build system requires specifically-written CMakeLists files to register components, you can't just include a normal CMakeLists (see the documentation).

Additionally, ESP-IDF is based on the real-time operating system FreeRTOS, while libdatachannel requires a POSIX-compatible operating system, therefore building the library might require heavy patching.

[ayazalavi]

Can we generate .a file for libdatachannel?

[paullouisageneau]

The target datachannel-static will build a couple of ".a" static libraries:

$ cmake -B build -DCMAKE_BUILD_TYPE=Release
$ cd build
$ make datachannel-static
$ find -type f -name "*.a"

However, you can't just link static libraries built for your computer, you need them compiled for the ESP32.