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COSEBE
Senior
December 11, 2025
Question

STM32H5 Bootloader USB Stick mass storage

  • December 11, 2025
  • 2 replies
  • 516 views

Hi,

I want to start a new project with a STM32H503 (might be), and I read many threat talking about USBX FILEX now on this kind of microcontroller.
As it is a bootloader, I do not want to use any RTOS.
I use to do bootloader with USB host interface to update the firmware with STM32H7 or STM32F7, but with old stack.

Can you please confirm I will be able to develop a bootloader (usb host) to get a binary file on a USB stick storage using USBX and FILEX, WITHOUT any RTOS on a STM32H5 ?

Every exemple I found is for device standalone, not host USB.
Is there any up to date example with USB host MSC flash stick using USBX and FILEX to start ?

Sébastien

2 replies

TDK
Super User
December 15, 2025

 

> Can you please confirm I will be able to develop a bootloader (usb host) to get a binary file on a USB stick storage using USBX and FILEX, WITHOUT any RTOS on a STM32H5 ?

Since USBX and FILEX are designed to be used with an RTOS, you're unlikely to find many examples of them being used without one.

Could they be stripped away from the RTOS? Yes, but it will be an uphill battle. Whether or not you will succeed in implementing it depends on your experience and dedication. If you are inexperienced, I recommend using the existing examples and supported RTOS implementations.

"If you feel a post has answered your question, please click ""Accept as Solution""."
Pavel A.
Super User
December 16, 2025

IIRC, you can configure USBX without RTOS - but not sure about FILEX.

Consider the "legacy" ST USB library with fatfs?

As always - if the task looks like too much trouble, outsource it here.

 

COSEBE
COSEBEAuthor
Senior
December 16, 2025

>Consider the "legacy" ST USB library with fatfs?

Yes, I might do this.

But why ST team proposes only USBX and FILEX now, and ST USB library become "legacy."
What is the goal ?

Why do they force us to use a RTOS ?

Why don't they let ST USB usable with STM32CubeMX as simple as it was ?

I do not understand the philosophy.