TFM 2.3.0 integration to zephyr main for nucleo_u3c5zi_q

[mkaricheri]

Hi Zephyr experts,

I need to get TFM support working on nucleo_u385rg_q. Recently ST Micro has added support for TFM to nucleo_u3c5zi_q in TFM 2.3.0. nucleo_u385rg_q is close match of nucleo_u3c5zi_q .

1. So my first question is when will TFM 2.3.0 be integrated with Zephyr main?
2. Since I don't have what I need, I am venturing into doing this myself. Is there any Gotchas I need to be aware of before I do this?

Here is my path to achieve the goal as I see it. Please let me know if it make sense

1. I have b_u585i_iot02a board. So first step is to change west.yml to pick the latest commit id from TFM 2.3.0
2. Do a west update and build TFM for b_u585i_iot02a tfm sample application and boot test
3. Now add required files (ns DTS) for nucleo_u3c5zi_q and rebuild tfm sample application. I don't have the board, but I have nucleo_u385rg_q.
4. Re-use platform files from nucleo_u3c5zi_q for nucleo_u385rg_q and adjust the flash_layout.h to account for the smaller flash it has (1MB vs 2MB). Will allocate 128KB for BL2, 128KB each for Primary and Secondary secure image, 388KB each for primary and secondary Zephyr (non secure) application. Will the current BL2 and Secure image will fit into this flash partitions?
5. Add required updates in Zephyr for nucleo_u385rg_q (ns DTS)
6. Build and test the tfm sample application on nucleo_u385rg_q

Thanks in advance for your valuable input.

Murali

[mkaricheri]

I found integrating TFM 2.3.0 to zephyr main is very complicated. So alternately, I tried picking the below commit to the current version of TFM module used by zephyr main. Even that is running into issues. For example it is missing some BL2 related files. So continuing in this path and if someone can provide some help, much appreciated.

tfm commit : da616c541 Platform: STM32: Add support of nucleo_u3c5zi_q

Wondering if there is some work for nucleo_u3c5zi_q support that I can leverage??

[tpambor]

You can try again with current main. The integration of TF-M 2.3.0 into main branch of Zephyr has been completed and your mentioned TF-M commit is part of it. nucleo_u3c5zi_q isn't yet supported but you can follow along how TF-M support has been added for other boards e.g. #100114.

[gautierg-st]

Hello @mkaricheri,
TFM integration for the Nucleo-U3C5ZI-Q in Zephyr is currently being worked on on our side but is not yet ready. I hope to push a working PR before the end of next week.