Hacked (reprogramming) ST-Link (with STM32) from STM8S Discovery to Arduino

Some time ago i was using STM8S Discovery boards,
once a couple of STM8S microcontrollers have been put permanently to work i left around some ST-Link boards, cracked off by these dev kits.
These boards contain STM32F103C8T6 microcontroller, so why not to use it?
Here is my hack with blink sketch and serial communication running, written using Arduino IDE,
thankful to stm32duino community.
Steps:
-Solder insulated wires to BOOT0, PA9, PA10 and RST pins
-Connect it to a USB to RS232 TTL adapter
-Remove the write protection with "Flash loader demonstrator"
(MCU will be erased and you will lose ST-Link functionality)
-Ready to be programmed through USART with builtin bootloader