How to create an M33-TD boot project using STM32CubeIDE

This article explains, as example,

how to create, with STM32CubeIDE, boot and secure project in case of Arm^®-Cortex^®-M33 boot flavor, for STM32MP25x lines ,
how to configure and debug TF-M.

It explains how to:

populate STM32MP257F-EV1 Evaluation board with M33-TD image on :
- sNOR for Arm^®-Cortex^®-M33,
- SD card for Linux^® Arm^®-Cortex^®-A35,
update Arm^®-Cortex^®-M33 firmware thanks to a dedicated version of STM32CubeIDE release 1.17.0.25-MP25-CM33TD-BETA, available on myteamspace/MCD Alpha - STM32MP25_M33-TD.

Warning

OpenSTLinux projects running on Arm^®-Cortex^®-A and located on SD card are not updated here.

Empty project creation has no specific option for CM33TDCID profile, it relies on trusted-firmware-M CMake project customization.

STM32Cube projects, with customized device trees, are created outside STM32CubeIDE thanks to STM32CubeMX stand-alone, and imported inside STM32CubeIDE.

Important

Arm^®-Cortex^®-A35 BL2 binaries must always be aligned with boot mode. Information in this article corresponds to M33TD boot. If you modify the configuration / device tree for Arm^®-Cortex^®-A35 BL2, you must generate the binaries but you can not with the way of working defined in this article.

For that, you need to use the distribution package. More information related to distribution package are available in the Release notes available on myteamspace/MCD Alpha - STM32MP25_M33-TD

1. Prerequisites[edit | edit source]↑

1.1. Hardware prerequisites[edit | edit source]↑

Linux^® or Windows^® host PC must be connected to the board to enable:
- Arm^®-Cortex^®-A35 console,
- Arm^®-Cortex^®-M33 console.

STM32MP257F-EV1 Evaluation board Rev D (ONLY). To set up the board, follow instructions given in STM32MP257x-EV1 - hardware description article.

1.2. Software prerequisites[edit | edit source]↑

On host PC:

Install build environment and toolchain, required for TF-M, as described in How to configure TF-M#Prerequisite prerequisite chapter.
Install python libraries needed by OP-TEE signature python script:

 pip install pyelftools
 pip install pycryptodomex

STM32CubeIDE release 1.17.0.25-MP25-CM33TD-BETA must be installed (to get Flash memory device feature, allowing sNOR target update). The installation executable are available on myteamspace/MCD Alpha - STM32MP25_M33-TD/Tools/CubeIDE. Depending on your host PC, select the right executable amongst the 4 available:
- Windows,
- Linux,
- Linux Debian package,
- Linux Ubuntu package.

STM32CubeProgrammer must be installed on your PC. Refer to STM32CubeProgrammer for installation procedure.

2. Set up embedded software[edit | edit source]↑

2.1. Populate the board with new OpenSTLinux release providing M33-TD boot[edit | edit source]↑

Retrieve the image, FLASH-stm32mp2-m33td-openstlinux-6.6-yocto-scarthgap-m33td-v25.01.03.tar, from myteamspace/MCD Alpha - STM32MP25_M33-TD/embedded software.
Flash your board with "FlashLayout_nor-sdcard_stm32mp257f-ev1-cm33tdcid-ostl-optee.tsv" available in the "FLASH-stm32mp2-m33td-openstlinux-6.6-yocto-scarthgap-m33td-v25.01.03.tar" in directory "stm32mp2-m33td-openstlinux-6.6-yocto-scarthgap-m33td-v25.01.03/images/stm32mp2-m33td/flashlayout_st-image-weston/optee/". How to flash with STM32Cube Programmer, is explained in STM32MP25_Evaluation_boards_-_Starter_Package#Image_flashing.

As explained in STM32MP25_Evaluation_boards_-_Starter_Package#Image_flashing, to flash, boot pins must be set as defined below:

Boot mode	Boot 3	Boot 2	Boot 1	Boot 0
UART/USB	0	0	0	0

Flashing board with STM32CubeProgrammer:

2.2. Boot the board[edit | edit source]↑

2.2.1. Configure boot pins[edit | edit source]↑

Once the embedded software has been downloaded in the board, specific boot pins configuration is needed to boot on Arm^®-Cortex^®-M33 with the wished dual mass storage:

Arm^®-Cortex^®-M33 from sNOR,
Arm^®-Cortex^®-A35 from SD card.

Boot mode	Boot 3	Boot 2	Boot 1	Boot 0
Arm^®-Cortex^®-M33 from sNOR Arm^®-Cortex^®-A35 from SD card	1	1	1	0

2.2.2. Create a second console[edit | edit source]↑

Two consoles are needed to check the dual boot.
For example, on OS Windows, they are available as COM12 & COM13.

The default one (COM12) is used for the Arm^®-Cortex^®-A35/Linux. It is available clicking on "MPU Serial console icon" . It is recommended to detach the associated windows. This can be done thanks to right menu on "Console" tab.
An additional console (COM13) is needed for Arm^®-Cortex^®-M33/FwST-M. To add a console goes in menus "Window > Show View > Other"... then "Connections > Connections" window. "New connection" icon opens a wizard where "Serial Port" can be selected.

Then, open a the console with "Open Console" icon from "Console window" and detach it.

2.2.3. Start your board[edit | edit source]↑

To boot your board, you need to reset it by pressing on the "reset button" on the board.

See dual boot steps, on the both consoles, in the screenshot below:

3. Get embedded software code source for further updates[edit | edit source]↑

Only TF-M, TF-M tests, and External device tree are needed to create M33-TD boot and secure project.

TF-M and TF-M tests components must be updated, for that, git clone them on your local disk:

trusted-firmware-m (https://github.com/PRG-MPU-ALPHA/trusted-firmware-m.git) CMake secure project, implementing ST device customization (branch: v1.7.0-stm32mp25-alpha-w2450; tag: v1.7.0-stm32mp25-alpha-r1).
tf-m-tests (https://github.com/PRG-MPU-ALPHA/tf-m-tests) CMake nonsecure project starting Linux on Cortex^®-A (branch: v1.7.0-stm32mp25-w2446; tag: v1.7.0-stm32mp25-alpha-r1).

CMAke projects are needed as source to config and recompile and debug the TF-M. Objective is to customize the TF-M and TF-M tests (which is an example of use).

External device tree component must be also updated (External DT is needed to start cortex-A), for that, git clone it on your local disk:

dt-stm32mp (https://github.com/PRG-MPU-ALPHA/dt-stm32mp) (branch: main; tag: v6.0-stm32mp-alpha-r1).

4. Create, build and populate a M33-TD boot project[edit | edit source]↑

To create the "M33-TD boot project" , you need first to create an STM32CubeIDE "empty" project, to import the CMake project delivered in TF-M.

Then configuration will be possible in TF-M, TF-M tests.

4.1. Create an STM32CubeIDE empty project[edit | edit source]↑

To create an STM32CubeIDE empty project:

"File > New > STM32 Project"... ,
Then, type in "Board selector" > "Commercial Part Number": "MP257F-EV1"... and then "Next".

Selecting "STM32MP257F-EV1 board" creates "empty" project, with TrustZone enabled, named here "myStm32mp257f".

Warning

The project created has the name myStm32mp257f on the screenshots below and texts, do not forgot to update with your own project name.

In STM32 Project wizard, fill "Project Name", select "Empty" "Targeted Project Type" and "Finish".

4.2. Import Trusted-firmware-M CMake project in STM32CubeIDE[edit | edit source]↑

Then import CMake project inside STM32CubeIDE "myStm32mp257f" "empty" project.

For that, select "myStm32mp257f_CM33" project and right click to "Create a STM32 CMake Project using existing CMake sources" menu.

Set "Source directory" to trusted-firmware-M CMake project. For that use "Browse".
- Set "Source directory" field to "trusted-firmware-m local repository".
- Set appropriate "Project name" field to "myStm32mp257f_CM33_trusted-firmware-m".
- Click "Next".

Then, fill debug information giving MCU, CPU and Core.

"myStm32mp257f_CM33_trusted-firmware-m" project is now visible inside STM32CubeIDE project.

As depicted here after, "trusted-firmware-M" is a link to local repository.

Trusted-firmware-M sources stay physically in your local directory but they are visible in STM32CubeIDE thanks to a link.

Empty project creation has no specific option for CM33TDCID profile, it relies on "trusted-firmware-M" CMake project customization.

You can now refresh STM32CubeIDE project and view sources.

4.3. Configure Trusted-firmware-M CMake project[edit | edit source]↑

Select "myStm32mp257f_CM33_trusted-firmware-m" project and right click to get "Properties".

Then:

Choose "C/C++ Build".
Select the "CMake Settings" tabulation where "Other options" must be filled with configuration given below.

tf-m CMake configuration

Below is given, the CMake configuration to apply:

It uses "tf-m-tests" nonsecure project which start Linux on Cortex-A.
The device tree, used in native OpenSTLinux, are needed.
The debug mode is activated in BL2.

For Windows host PC Click on "Expand", visible on the right side of the page

-DTFM_PLATFORM=stm/stm32mp257f_ev1
-DTFM_TOOLCHAIN_FILE=toolchain_GNUARM.cmake
-DTFM_PROFILE=profile_medium
-DSTM32_M33TDCID=ON
-DCMAKE_BUILD_TYPE=Relwithdebinfo
-DTFM_TEST_REPO_PATH="C:\ <PATH-TO-TF-M-TESTS>\tf-m-tests"
-DSTM32_BOOT_DEV=ospi
-DDEBUG_AUTHENTICATION=FULL
-DDTS_EXT_DIR="C:\<PATH-TO-EXTERNAL-DT>\tfm"
-DDTS_BOARD_BL2=stm32mp257f-ev1-cm33tdcid-ostl-bl2-nor.dts
-DDTS_BOARD_S=stm32mp257f-ev1-cm33tdcid-ostl-s-sdcard.dts
-DDTS_BOARD_NS=stm32mp257f-ev1-cm33tdcid-ostl-ns.dts

Warning

You have to update path to tf-m-tests project and OpenSTLinux device tree with your own paths.

Same configuration is given below to make easy copy/paste. Do not forget to change also the PATHs in the copied configuration:

-DTFM_PLATFORM=stm/stm32mp257f_ev1 -DTFM_TOOLCHAIN_FILE=toolchain_GNUARM.cmake -DTFM_PROFILE=profile_medium -DSTM32_M33TDCID=ON -DCMAKE_BUILD_TYPE=Relwithdebinfo -DTFM_TEST_REPO_PATH="C:\<PATH-TO-TF-M-TESTS>\tf-m-tests" -DSTM32_BOOT_DEV=ospi -DDEBUG_AUTHENTICATION=FULL -DDTS_EXT_DIR="C:\<PATH-TO-EXTERNAL-DT>\tfm" -DDTS_BOARD_BL2=stm32mp257f-ev1-cm33tdcid-ostl-bl2-nor.dts -DDTS_BOARD_S=stm32mp257f-ev1-cm33tdcid-ostl-s-sdcard.dts -DDTS_BOARD_NS=stm32mp257f-ev1-cm33tdcid-ostl-ns.dts

For Linux host PC Click on "Expand", visible on the right side of the page

-DTFM_PLATFORM=stm/stm32mp257f_ev1
-DTFM_TOOLCHAIN_FILE=toolchain_GNUARM.cmake
-DTFM_PROFILE=profile_medium
-DSTM32_M33TDCID=ON
-DCMAKE_BUILD_TYPE=Relwithdebinfo
-DTFM_TEST_REPO_PATH=<PATH-TO-TF-M-TESTS>/tf-m-tests
-DSTM32_BOOT_DEV=ospi
-DDEBUG_AUTHENTICATION=FULL
-DDTS_EXT_DIR=<PATH-TO-EXTERNAL-DT>/tfm
-DDTS_BOARD_BL2=stm32mp257f-ev1-cm33tdcid-ostl-bl2-nor.dts
-DDTS_BOARD_S=stm32mp257f-ev1-cm33tdcid-ostl-s-sdcard.dts
-DDTS_BOARD_NS=stm32mp257f-ev1-cm33tdcid-ostl-ns.dts

Warning

You have to update path to tf-m-tests project and OpenSTLinux device tree with your own paths.

Same configuration is given below to make easy copy/paste. Do not forget to change also the PATHs in the copied configuration:

-DTFM_PLATFORM=stm/stm32mp257f_ev1 -DTFM_TOOLCHAIN_FILE=toolchain_GNUARM.cmake -DTFM_PROFILE=profile_medium -DSTM32_M33TDCID=ON -DCMAKE_BUILD_TYPE=Relwithdebinfo -DTFM_TEST_REPO_PATH=<PATH-TO-TF-M-TESTS>/tf-m-tests -DSTM32_BOOT_DEV=ospi -DDEBUG_AUTHENTICATION=FULL -DDTS_EXT_DIR=<PATH-TO-EXTERNAL-DT>/tfm -DDTS_BOARD_BL2=stm32mp257f-ev1-cm33tdcid-ostl-bl2-nor.dts -DDTS_BOARD_S=stm32mp257f-ev1-cm33tdcid-ostl-s-sdcard.dts -DDTS_BOARD_NS=stm32mp257f-ev1-cm33tdcid-ostl-ns.dts

Now, it is possible to configure CMake"myStm32mp257f_CM33_trusted-firmware-m" project.

Warning

Process running STM32CubeIDE must define http and https proxy in order "CMake" command to successfully access network.

On Linux^® workstation, it is recommended to launch STM32CubeIDE from "xterm" with configured proxy environment.

Select "myStm32mp257f_CM33_trusted-firmware-m" project and right click to "CMake Configure".

4.4. Build created project with STM32CubeIDE[edit | edit source]↑

As mentioned in How to configure TF-M, "trusted-firmware-m" project is built with build target "install".

Then:

Choose "C/C++ Build".
Select the "Behavior" tabulation where the field "Build (Incrementale build)" must be checked and filled with "--target install".
Then click on "Apply and close".

tf-m project build setup

It is now possible to build trusted-firmware-m and tf-m-tests using standard Eclipse "Build icon".

Warning

Process running STM32CubeIDE must define http and https proxy in order CMake command to successfully access network.

On Linux^® workstation, it is recommended to launch STM32CubeIDE from xterm with configured proxy environment.
Note that on Windows, you may need to copy python.exe as python3.exe to complete build.

4.5. Populate board with the created M33-TD boot project with STM32CubeIDE[edit | edit source]↑

STM32CubeIDE proposes "Flash device memory" menu, based onto STM32CubeProgrammer and its .tsv files.

It is recommended

to copy original .tsv file "FlashLayout_nor-sdcard_stm32mp257f-ev1-cm33tdcid-ostl-optee.tsv" inside its directory,
and to rename it adding STM32CubeIDE "myStm32mp257f" project name: "FlashLayout_nor-sdcard_stm32mp257f-ev1-cm33tdcid-ostl-optee_myStm32mp257f.tsv".

.tsv file copy

In this new .tsv file, you must change <YOUR PATH> by the path of the directories containing the binaries generated in previous chapter.

The .tsv file can be then used, after any image generation.

Warning

Take care : when TF-M is built some new signing keys are generated and used to generate the new binaries (see previous chapter to know how to generate binaries). That means you need to always flash the BL2 AND the TF-M_S_NS signed

Update .tsv file with generated binaries paths

Select "myStm32mp257f_CM33_trusted-firmware-m" project and right click to get "Program memory device".

Program memory device menu

Update on-board flash: sNOR and SD card here: GO in Tab "Flash memories programmer":
- Fill "Binaries Directory" with the path to binaries inside OpenSTLinux images.
- Fill "TSV File" with the updated .tsv file.
- Click on "Download" button.

Updating target...

5. Configure the debug option[edit | edit source]↑

Debug is based onto -DDEBUG_AUTHENTICATION=FULL build flag. With this flag, BL2 opens debug port and waits a debugger connection.
The picture below shows the Arm^®-Cortex^®-M33 console, on reboot, after target update using this set-up.

BL2 waiting for debugger in Arm^®-Cortex^®-M33 Console

5.1. Prerequisite for debugging[edit | edit source]↑

As prerequisite, "myStm32mp257f_CM33_trusted-firmware-m" project needs to be updated.

First, in "Project explorer", click on "View Menu" icon and select "Filters and Customization".

Unselect ".* resources" choice.

Open, with "Text Editor", ".project" file inside "myStm32mp257f_CM33_trusted-firmware-m" project and add two project nature:

<nature>com.st.stm32cube.ide.mcu.MCUProjectNature</nature>
<nature>com.st.stm32cube.ide.mpu.MPUEmbeddedMCUProjectNature</nature>

5.2. Debug configuration creation[edit | edit source]↑

Select "myStm32mp257f_CM33_trusted-firmware-m" project and right click to get "Debug As" > "Debug configurations".

Double click "STM32 C/C++ Application" and edit debug configuration:

In "main" tabulation, "Search Project" and select "bl2.elf".
In "Debugger" tabulation, "Load Mode" and select "thru JTAG/SWD link (Engineering mode)".
In "Startup" tabulation:
- Disable "Resume".
- Select the "Load Image and Symbols" element click "Edit" and disable "Download".

Debug configuration - Startup tab

"Apply" and "Debug".

Launching debug session

Now, you can step into BL2 code, and if you resume it, will start Linux^® on Arm^®-Cortex^®-A35.

Resuming after step into BL2 code