How to upgrade a STM32 project

Overview

This article describes how to upgrade an STM32CubeMX-based or proprietary source tree with a new version of the STM32 runtime library. The update of generated C-model files is explained in the “Update an ioc-based project” section. For the interface between them, backward and/or forward compatibility is never guaranteed. If the generated C-model files are updated with a new version of the STEdge Core AI tools, the library files should also be aligned. Without specific notification or advice (see the “CLI” and “Embedded C-API” sections in the release note), no breaking changes to the embedded inference API that could break the client’s application are expected.

A typical source tree ( %STEDGEAI_CORE_DIR% indicates the root directory of the project):

../../_images/how_to_upgrade_lib_src_tree1.png

  • If the project source tree has been generated through a STM32CubeMX-based project with the X-CUBE-AI expansion pack, the IOC-file can be reloaded to update the project including a new version of the X-CUBE-AI pack.

  • A typical command to update the generated C-model files using the CLI in the project source tree is:

    stedgeai generate -m <my_model> <my_options> -o %ROOT_PRJ_DIR%/model

Warning

It is recommended to compile the application using the same compilation options as the library to ensure compatibility. Additionally, link the application with the same toolchain used to build the library to avoid potential issues.

Network runtime library

The C-header files and network runtime libraries should be directly copied from the installed STEdge AI core pack. The %STEDGEAI_CORE_DIR% indicates the root location where the STEdge AI core pack is installed.

Directory

Contains

%STEDGEAI_CORE_DIR%/Middlewares/ST/AI/Inc

all C-header files requested to build the generated c-model files

%STEDGEAI_CORE_DIR%/Middlewares/ST/AI/Lib

by STM32 series and by toolchain, the network runtime libraries

Library naming convention 

NetworkRuntime<version>_<core>_<toolchain>[_<extra>].<extension>

  • <version>: Indicates the version of the library (always aligned with the version of the STEdge AI core).

  • <core>: Specifies the targeted Arm® Cortex® core.

  • <toolchain>: Specifies the embedded ARM toolchain used to generate the library.

  • <extra>: (optional): Provides additional description if a specific case or variant is generated (e.g., when default options are overridden).

  • <extension>: The library file extension, which depends on the toolchain.

Compilation options

All libraries are generated as static libraries. When applicable, the hard FPU ABI ( -mfloat-abi=hard) is used; otherwise, the soft FPU ABI ( -mfloat-abi=soft) is defined if no FPU support is available. According to the toolchain used, optimization for speed ( -Ofast) is applied, and all libraries are delivered without debug information.

  • ‘armcc’ designates the Keil® MDK-ARM Professional - ARM Compiler 5 toolchain.

  • ‘armclang’ designates the Keil® MDK-ARM Professional - ARM Compiler 6 toolchain.

  • ‘armgcc’ designates the GNU ARM Embedded toolchain from the STM32CubeIDE/STM32CubeCLT package.

  • ‘armiar’ designates the IAR Embedded Workbench® IDE toolchain.

Options for STM32F0, STM32G0, STM32L0 and STM32WL series (Arm® Cortex® w/o FPU)

compiler feature

armcc

armclang (*)

armgcc

armiar

wchar and enum size

short wchar, smallest enum

short wchar, smallest enum

32b wchar, smallest enum

32b wchar, smallest enum

float-abi

soft

soft

soft

soft

optimization

-O3

-O3

-Ofast

-Ohs

(*) For armclang, the following options are used to overwrite the default behavior: -fshort-wchar -fshort-enums -funsigned-char.

Options for other STM32 series

compiler feature

armcc

armclang (*)

armgcc

armiar

wchar and enum size

short wchar, smallest enum

short wchar, smallest enum

32b wchar, smallest enum

32b wchar, smallest enum

float-abi

hard

hard

hard

hard

optimization

-O3

-O3

-Ofast

-Ohs

(*) For armclang, the following options are used to overwrite the default behavior: -fshort-wchar -fshort-enums -funsigned-char.

For the STM32 series (STM32N6 and STM32N8) based on the Arm® Cortex® M85/M55 core, the libraries are compiled with the Arm Helium technology support (default configuration).

Subdirectory organization by toolchain

The root folder ( %STEDGEAI_CORE_DIR%/Middlewares/ST/AI/Lib) contains subdirectories for different toolchains, each providing libraries compatible with specific development environments:

Subdirectory

Contains

ABI2.1

Libraries for the IAR Embedded Workbench® IDE targeting ARM v8.x/v9.x toolchain or later.

GCC

Libraries for GNU ARM Embedded projects, compatible with STMicroelectronics STM32CubeIDE version 1.0.1 or later.

MDK

Libraries for Keil® MDK-ARM Professional environment.

Subdirectory organization by STM32 Series

Inside each toolchain directory, there are subdirectories organized by STM32 series. Select the folder that matches your target STM32 device series. If a specialized series folder is not available, use the generic STM32 Cortex-M folder.

In each <tool-chain> directory, there is one subdirectory per STM32 series. According to the targeted STM32 device, select the specialized STM32 series folder first; otherwise, use the generic STM32 Cortex-M/R/A folder.

Folder Name

Description

STM32WL

Specialized library for the STM32WLxx series

STM32MP1

Specialized library for the Arm® Cortex® M4 core inside STM32MP1 devices

STM32H7

Specialized library for the STM32H7xx series

ARMCortexM0

Devices based on the Arm® Cortex® M0, STM32F0xx serie

ARMCortexM0+

Devices based on the Arm® Cortex® M0+, STM32L0xx, STM32G0xx, STM32C0xx series

ARMCortexM4

Devices based on the Arm® Cortex® M4, STM32F3xx, STM32L4xx, STM32F4xx series

ARMCortexM7

Devices based on the Arm® Cortex® M7, STM32F7xx serie

ARMCortexM33

Devices based on the Arm® Cortex® M33, STM32U3xx, STM32L5xx, STM32U5xx, STM32C5xx, STM32G5xx series

ARMCortexM55

Devices based on the Arm® Cortex® M55, STM32N6xx series

ARMCortexM85

Devices based on the Arm® Cortex® M85, STM32V8xx series

ARMCortexA35

Devices based on the Arm® Cortex® A35, STM32MP2 series (bare-metal mode)

Warning

When the project source tree is updated, don’t forget to update also the associated build system to use the new library file.

Note

Library files with the name suffixed with _PIC should be not used.

Toolchain versions

Toolchain

Version

MDK

For the STM32 series based on the Arm® Cortex® M85/M55/M33, the MDK Professional 5.40 with Arm Compiler for Embedded 6.22 is used to generate the MDK libraries else ARM Compiler 5.06 is used.

GCC

GNU ARM Embedded (STM32 13.3.rel1.20240926-1715) 13.3.1 is used for all series.

ABI2.1 - IAR Embedded Workbench® IDE

IAR ANSI C/C++ Compiler V9.40 for ARM is used for the STM32N6 and STM32V8 series else the IAR ANSI C/C++ Compiler V8.5 for ARM is used for the other targets.

Specific library for STM32N6 series

For performance reasons (approximately 10–20% faster execution time), a compatible library compiled with the MDK Arm Compiler for Embedded 6.22 toolchain is provided for use in GCC or IAR application environments. The library file is located at: 

MDK\ARMCortexM55\NetworkRuntime1102_CM55_Keil_COMPATIBLE.a

The following compilation options are used:

  • -fno-short-wchar

  • -nostdlib

  • -funsigned-char

  • -fshort-enums

Upgrading the X-CUBE-AI library for a STM32F411 device and GCC-base build system 

# remove the previous files
rm %ROOT_PRJ_DIR%/Middlewares/ST/AI/Inc/*.h
rm %ROOT_PRJ_DIR%/Middlewares/ST/AI/Lib/*.a
# copy the new files
cp %X_CUBE_AI_DIR%/Middlewares/ST/AI/Inc/*  %ROOT_PRJ_DIR%/Middlewares/ST/AI/Inc/
cp %X_CUBE_AI_DIR%/Middlewares/ST/AI/Lib/GCC/ARMCortexM4/NetworkRuntime700_CM4_GCC.a
     %ROOT_PRJ_DIR%/Middlewares/ST/AI/Lib/

Upgrading the X-CUBE-AI library for a STM32H7xx device and Keil IDE 

# remove the previous files
rm %ROOT_PRJ_DIR%/Middlewares/ST/AI/Inc/*.h
rm %ROOT_PRJ_DIR%/Middlewares/ST/AI/Lib/*.a
# copy the new files
cp %X_CUBE_AI_DIR%/Middlewares/ST/AI/Inc/*  %ROOT_PRJ_DIR%/Middlewares/ST/AI/Inc/
cp %X_CUBE_AI_DIR%/Middlewares/ST/AI/Lib/MDK/STM32H7/NetworkRuntime700_CM7_Keil.lib
     %ROOT_PRJ_DIR%/Middlewares/ST/AI/Lib/