Hi,
You can find a complete
application written in assembler in the ST7/STM8 Assembler manual (MASTM8.pdf) document.
However, the example is for ST7 only. Here is an example that shows how to make the equvalent in STM8 mode; the example includes vectors definition, reset etc, but does not do anything useful.
Note that this is given as an example, but it is much more efficient to write STM8 applications in C rather than assembler.
Also the CircleOS applications must be in C, it is not possible (or relevant?) to write them in assembler.
Best Regards,