Version for review planed for wk18
Target description
The purpose of this article is to explain how to proceed step by step to generate a boot path using STM32CubeMx.
The example below will show how to configure and provision a boot path for an OEMiROT with a secure and non-secure user application initial code generation.
Read the Secure Boot STM32H5 How to Introduction article before starting the practical example described below.
More technical details you may need to understand this getting started are available in the following articles:
- Introduction article: Introduction to Secure boot and Secure firmware update.
- Specific STM32H5 bootpaths article: Secure Boot for STM32H5
- OEMiROT article OEMiROT for STM32H5 MCUs
The How to start described in this article is using the Boot path number 1 of the figure below.
Prerequisites
To execute the example described below, you need:
- Discovery board: STM32H573I-DK|
- The following tools:
- STM32CubeMx_6.9.0 or later (for installation, see appendix)
- IAR Embedded Workbench rev 9.20.1 or later
Note:
- STM32 Trusted Package Creator (TPC) is automatically installed during the STM32CubeMX installation. There is a TPC version dedicated to STM32CubeMX and installed in the STM32CubeMX/utilities folder.
- The latest STM32Cube_FW revision is installed through STM32CubeMX (see appendix)
- If needed set the windows environment variable (see appendix). It is required in case the H5 doesn’t appear in the “Access to MCU Selector” of STM32CubeMx
1. Setting the STM32CubeMX project
Launch STM32CubeMX
- 1) Click on Access to MCU selector (easier for this example to enable only the needed GPIOs, so it's advised to use the MCU selector instead of the board selector).
- 2) Select STM32H5 serie and select the device used in STM32H5-DK
- 3) Click start project
- 4) Enable the TrustZone, as shown in the figure 1, for the OEMiROT bootpath the TZ needs to be enabled.
Set the STM32CubeMX project:
- 1) Type the name of the project (the related folder will be created)
- 2) Chose the folder for this project (avoid long path)
- 3) Tick both: Secure and non Secure projects
- 4) Select the Toolchain, for this example EWARN is used
- 5) File -> Save Project -> the project folder (if not already existing) and the STM32H5_STiROT_SLed_NSLed.ioc file is created
2. GPIO configuration
For this proposed example three GPIO need to be configured for the discovery board:
- PF4 for the blue LED used in the secure user application code
- PC13 for the blue user button used in the secure user application code
- PI9 for the green LED used in the non-secure user application code
In the STM32CubeMX select the Pinout & Configuration window
To configure the GPIO for the blue LED proceed as follow:
- Click left on PF4: select GPIO_Output -> a push pull output will be configured need to drive an LED
- Click right on PF4: and select Cortex-M33 secure. This GPIO is then assigned to the secure user application code
To configure the user bue button proceed as follow:
- Click left on PC13: select GPIO_Input
- Click right on PC13: and select Cortex-M33 secure. This GPIO is then assigned to the secure user application code
To configure the GPIO for the green LED proceed as follow:
- Click left on PI9: select GPIO_Output -> a push pull output will be configured need to drive an LED
- Click right on PI9: and select Cortex-M33 non-secure. This GPIO is then assigned to the non-secure user application code
- Select GPIO: the summary of the settings are displayed as shown in the figure below
3. Debug Authentication configuration
Refer to the Debug_Authentication_for_STM32H5_MCUs article for more details.
A default configuration file (fully functional) and related OBKey file are provided through the STM32CubeFW.
To customize the Debug Authentication proceed as following:
- In STM32CubeMx -> Project Manager -> Select: Debug Authentication Configure.
- The STM32Trusted Package Creator is launched (TPC installed together with STM32CubeProgrammer) and the DA_Config.xml file is automatically open.
- The "key_1_root" key is needed to reopen the device or to perform a regression. To protect you own developed application, this key needs to be regenerated. If regenerated, it's important to not lose this new key.
- Don't regenerate the key for this example
- The permission mask is set to allow all possible regressions and debug openings in the secure and non-secure user application. See Debug_Authentication_STM32H5_How_to_Introduction article for more details.
This permission mask, called the SOC mask is stored in the device during the provisioning process.
The owner of the root key has then the defined privileges to perform a regression or open the debugger according set permissions.
- Generate the OBKey file that will be used during the provisioning, click:
- Close STM32Trusted Package Creator
4. Configure the OEMiROT bootpath
To configure the bootpath number 2 of the figure 1 proceed as follow:
- 1) Click on "Boot Path and Debug Authentication"
- 2) Click on "Select"
- 3) Select the OEM-iROT. The TZ activation has already been chosen, this selection is defining the UBE option byte (but you don't need to take care about the setting of this option byte).
- 4) Click on "Next"
- 5) Select Secure Application (since for this example there is no uROT, so no second boot stage)
- 6) Click Finish
In the Project Manager window, select Edit Config, as shown in the figure below.
It will automatically open STM32Trusted Package Creator (TPC).
And the following window is displayed.
- Generate the OBKey file :
5. Appendix
5.1. STM32CubeFW installation
The STM32CubeFW needs to be installed through STM32CubeMX.
- Step 1: the repository folder has to be defined:
- In CubeMx: Help menu -> Updater Settings
- Browse the repository you have chosen for the STM32CubeFW
- Step 2: STM32CubeFW installation
- In STM32CubeMX: Select Install/Remove
- In the description frame: select STM32H5
- Select the CubeFW package to install
- In case you have locally the zip file of the STM32CubeFWH5: it can be installed by drag and drop this file in the description window
Note: only official STM32CubeFW release can be installed by STM32CubeMX.