2026-03-28 1:22 AM
Hi,
I'm using the STM32U5G9J-DK1 Demo Board with the STM Demo Program Ux_Device_DFU, because I need to create a specific bootloader for my board.
The STM32CubeProgrammer program connects to the board via USB and I can read its memory, but the program doesn't receive information from the Flash Blocks, so programming doesn't start.
If I enable the Bootloader available in the MPU's system memory, the programming via the STM32CubeProgrammer works correctly.
What should I change in the STM source code to avoid this problem?
Thank you in advanced
Solved! Go to Solution.
2026-03-28 3:46 AM
Hi @Doriano Quarti,
Thank you for the quick feedback, yes Indeed that Demo is quite old and not maintained for newer STM32 with different Flash Topologies and specific customization across the whole Portfolio from 180nm to 40nm geometry and densities including the dual bank features . But it seems working fine for you up to 1MBytes , so the firmware implementation should be adapted to support that in the example .
My recommendation to explore our Open bootloader example that should be supported by the STM32CubeProgrammer here :
https://github.com/STMicroelectronics/stm32-mw-openbl?tab=readme-ov-file
Let us know
STOne-32
2026-03-28 3:24 AM
Dear @Doriano Quarti ,
For a quick test , can you run this Application DfuSe demo instead of CubeProgrammer to see if the same behavior , even not recommended for new design . To check if it is Embedded Firmware issue or PC app ?
https://www.st.com/en/development-tools/stsw-stm32080.html
Thank you .
STOne-32
2026-03-28 3:33 AM
Thanks for rthe answer
I started from the DfuSe Demo programmer that I sue from more than 20 years, but, using the same Ux_Device_DFU code, I found a problem when i tried to download a code with a size more than 1 MBytes.
I search in the comunity and I found that the DfuSe Demo programmer is a old Program and so it is better to migrate to the STM32CubeProgrammer.
Thank you
Doriano
2026-03-28 3:46 AM
Hi @Doriano Quarti,
Thank you for the quick feedback, yes Indeed that Demo is quite old and not maintained for newer STM32 with different Flash Topologies and specific customization across the whole Portfolio from 180nm to 40nm geometry and densities including the dual bank features . But it seems working fine for you up to 1MBytes , so the firmware implementation should be adapted to support that in the example .
My recommendation to explore our Open bootloader example that should be supported by the STM32CubeProgrammer here :
https://github.com/STMicroelectronics/stm32-mw-openbl?tab=readme-ov-file
Let us know
STOne-32
2026-04-01 6:29 AM
Hi STOne-32
I imported the OpenBootloader softwarein my custom bootloader project, and everything works fine.
I can download a Application Program larger than 1 MByte using both the DfuSe Demo program and the STM32CubeProgrammer.
However, I noticed a significant slowness compared to a download performed using the Bootloader Internal to the device's System Memory.
I also noticed the same slowness when using your STM32U5G9J-DK1 demo board with your bootloader application included in the STM32Cube_FW_U5_V1.7.0 package.
Do you have any suggestions for improving this?
Thanks in advanced.
Doriano