how i can change the baudrate for the seriel connection?
Can you be more specific? If you are talking about the pcengines APU machines, IPFire has nothing to do with the serial port communication. That is set in the firmware (as far as I know) and it cannot be changed. Of course you can change it in your client to connect to the serial port and open a console communication, but that depends on the client you are using. If you were asking something else, then you should tell more in detail what you want to do.
it is x86 hardware.
previously you could adjust the settings under / etc in the bootloader. now I can’t find it there anymore
Do you mean
you can try
stty -F /dev/ttysomething 9600
yes its done… thank both!