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Visitor II
November 24, 2025
Solved

Flashing Zephyr Application to External Flash on Nucleo-H7S3L8

  • November 24, 2025
  • 3 replies
  • 223 views

 

I am working with Zephyr RTOS on the Nucleo-H7S3L8 board and have successfully flashed and run the blinky example on internal flash.

However, I noticed that Zephyr does not provide official documentation for flashing applications into external flash.

My question:

  • Does Zephyr offer any official method or west command to flash applications directly into external flash, similar to how west flash works for internal flash?
    This topic has been closed for replies.
    Best answer by Erwan Gouriou

    Please follow up on https://github.com/zephyrproject-rtos/zephyr/pull/99647

    This will introduce support of building and flashing of application on external flash using MCUBoot as bootloader, similarly to what is supported on DK Board (see https://docs.zephyrproject.org/latest/boards/st/stm32h7s78_dk/doc/index.html#application-in-external-flash)

     

    3 replies

    Technical Moderator
    November 25, 2025

    Hello @laya 

    STM32CubeProgrammer is setup as the default west runner for STM32 boards supported by Zephyr. For your case you can use STM32cubeProgrammer GUI instead of west commande to flash the code in external memory. 

    ST Employee
    November 25, 2025

    Hello @laya,

    I suggest that you program the external memory from the internal flash. So, you will XIP from external memory, then jump to internal flash in order to program the external memory then jump back to XIP.

    I hope my answer has been helpful. When your question is resolved, please mark this topic as the solution. This will help others find the answer more quickly.

    Thank you for your contribution.

    Best regards,
    Dor_RH

     

     

    ST Employee
    November 28, 2025

    Please follow up on https://github.com/zephyrproject-rtos/zephyr/pull/99647

    This will introduce support of building and flashing of application on external flash using MCUBoot as bootloader, similarly to what is supported on DK Board (see https://docs.zephyrproject.org/latest/boards/st/stm32h7s78_dk/doc/index.html#application-in-external-flash)