I'm not good at english
I tried using stm32cube programmer uart mode.
but "Error: Activating device: KO. Please, verify the boot mode configuration and check the serial port configuration. Reset your device then try again..." returned
I'm using stm32mp135 custom board, so i read stm32mp135 datasheet and found this part
I'm worried about USART3/6 and UART4/5/7/8 on "default pins"
I use uart4, but use another pin set.
uart4_TX -> PA9
uart4_RX -> PD8
Is the error related to this part?
Hello,
Here is what i did to use the UART mode with STM32CubeProgrammer and a DK32MP135F:
- all boot pin at zero 
- connect USB PWR and USB STlink cables
- launch STM32CubeProgrammer (v2.17.0)
- choose the good UART port, there are 2 VCP COM (COM20 and COM21 in my case), select the second one (COM21 in my case), I got the same error message as you when I selected the wrong one
- click on connect
In this mode, the USART/UART settings is done by the boot code.
rgds,
David
