Follow the instruction for building ESP32. At the last step, make works, but make BOARD=ESP32_GENERIC_C3 fails with error. $ make BOARD=ESP32_GENERIC_C3 Use make V=1 ...

ESP32 board platform: Tools -> Board ... -> Board Manager. Search "esp32" and install "esp32" by Espressif Systems. CP210x Unversal Windows Driver: https://www.silabs ...