IAP over SPI stm32u5

reedomneck · ‎2026-01-24

I need support to get IAP over SPI.

I've esp connected to my stm32u5 over SPI. Stm is slave and ESP is master.

For stm I've created project using stmcube by entering MCU part number.

Now here my question is

1. Do I need to develop bootloader code to achieve this.

2. How do I customise bootloader code.

3. STM boot pin is connected to ESP. do I need to control this?

4. Hwi do I adjust my memory or linker file

TDK · ‎2026-01-24

You can use the system SPI bootloader if the pins you have connected are compatible. See AN2606 for compatible pins and AN4286 for the protocol.

There are several IAP examples out there you could use. Here is one from ST:

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reedomneck · ‎2026-03-13

@TDK Thanks for sharing this resources.
So I should get started with openbootloader. For STM32U535 is this available?

TDK · ‎2026-03-13

There's an example for the U585. Implementation for U535 should be similar if not identical.

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