How can I avoid returning from bootloader after calling it. The bootloader sees a valid program in flash and so returning.

[berendi]

It depends on the MCU series, sometimes on the exact part number, and sometimes on the board (e.g. boot pin settings)

My crystal ball is not working, so you have to tell all relevant details.

[josef2]

Thank's for answer.

We are using actually using the stm32l011. Debugging shows, that I can jump into the bootloader. But if there is a valid code in flash, the bootloader is terminating and returns to flash. Is there a flag that I can set to stay in the bootloader or do I have to erase the first page in flash?

best regards

Josef