Question
STM32H7 + X-CUBE-SBSFU: How to change from UART YMODEM transfer to USB protocol.
Hi ST team,
I’m using X-CUBE-SBSFU v2.8.0 on STM32H753 (2_Images configuration), and I need guidance to move firmware transfer from UART YMODEM to USB protocol.
Current setup
- Platform: NUCLEO-H753ZI (also testing H753 EVAL migration)
- Project: 2_Images (SECoreBin + SBSFU + UserApp)
- Toolchain: STM32CubeIDE
- Current transfer path works: YMODEM over UART
- Goal: Transfer .sfb image over USB (preferably CDC), store in download slot, request install, reset, then let SBSFU verify/swap/launch
Observation
- Local loader is UART-based (SFU_LL_UART_* in sfu_com_loader.c)
- USB PCD appears not enabled by default in stm32h7xx_hal_conf.h
- In UserApp, install-at-next-reset flow is already working in fw_update_app.c
So i need some clarification
- What is ST-recommended architecture for USB transfer with SBSFU?
- USB in UserApp (receive file, write to DWL slot, call install-at-next-reset), or
- USB directly in SBSFU local loader, or
- Standalone loader approach?
- Do you have any official reference/example for SBSFU + USB CDC/DFU firmware update path on H7?
- Which files/modules are mandatory to adapt for a secure and supported implementation?
- Any constraints for header placement, packetization, alignment, or watchdog timing when source is USB instead of YMODEM?
- If CDC is preferred, should image still be transferred as .sfb into DWL slot exactly as YMODEM flow does?
Thanks in advance.