Arduino 1.8.13

http://dan.drown.org/stm32duino/package_STM32duino_index.json

STM32F1xx/GD32F1xx boards 
by stm32duino version 2021.2.22

  GENERIC STM32F103R series

  gd32f1_generic_boot20_pc13.bin
  generic_boot20_pc13.bin