STM32H503 OEMiROT: Unable to update new User application via USB

[Nowy]

Hello,
I am trying to run OEMiRoT on STM32H503 (NUCLEO-H503RB - MB1814B).
I followed the instructions specified: https://wiki.st.com/stm32mcu/wiki/Security:How_to_start_with_OEMiRoT_on_STM32H503
In step 6 ("Flash new User application in CLOSED state") after choosing option 1 ("Start Bootloader") in the terminal emulator, I cannot connect the board via UART/USB to the STM32CubeProgrammer.
To connect the board via UART to the STM32CubeProgrammer I had to perform a reset (RESET button). However, I cannot connect the board to the STM32CubeProgrammer via USB (User USB connector - CN3). The board with the USB cable connected performs continuous restarts.

[Dor_RH]

Hello @Nowy,

To resolve this issue, ensure the board is properly powered and verify the boot configuration settings (BOOT0 and BOOT1 pins). Make sure they are correctly set for USB bootloader mode.

Additionally, refer to:   

• STM32CubeProgrammer User Manual for detailed instructions on using the STM32CubeProgrammer

• STM32H503xx devices Application Note and Reference Manual for information on pin configurations and boot modes.

I hope my answer has helped you. When your question is answered, please select this topic as solution that answered you, it will help others find that answer faster.

Thanks for your contribution.

Dor_RH

[Nowy]

Hello @Dor_RH,

Thank You for your response. When using OEMiROT, the system bootloader is activated by software (OEMiROT) - jumping to the address of the system bootloader. The system bootloader activation method You mentioned refers to a hardware initiation (BOOT0 and BOOT1 pins).

[Nowy · Accepted solution]

The problem is MPU, which prevents execution outside of OEMiROT. Disabling OEMIROT_MPU_PROTECTION in boot_hal_cfg.h allows the application to be updated via USB.