esp-idf/examples/protocols/esp_http_client/main/CMakeLists.txt

# Embed the server root certificate into the final binary
#
# (If this was a component, we would set COMPONENT_EMBED_TXTFILES here.)
idf_component_register(SRCS "esp_http_client_example.c"
                    INCLUDE_DIRS "."
                    EMBED_TXTFILES howsmyssl_com_root_cert.pem)