Extracting esp32 image with esp32img tool

Install the requerments

sudo apt install python-pip
sudo pip install esptool pyserial

Get esp32img tool

git clone https://github.com/othercrashoverride/odroid-go-firmware.git -b factory
cd odroid-go-firmware/tools/esp32img

Extracting esp32 binary from your ODROID-GO

Connect your ODROID-GO to host PC via microUSB cable.
And then, run this command after the power switch on.

./esptool.py --port "/dev/ttyUSB0" --baud 921600 read_flash 0 0x800000 factory.bin

You can find the factory.bin

ls factory.bin

Make image to .img from .bin

./esp32img factory.bin

Write the image to your ODROID-GO

./esptool.py --port "/dev/ttyUSB0" --baud 921600 write_flash -z --flash_mode dio --flash_freq 80m --flash_size detect 0 factory.img