Linker error when generating a project with tflite runtime and cmake build on STM32F7 Discovery

[jjaccard]

Hello,

I am trying to build a simple AI app on my stm32f7 discovery board.

In VSCode when I try to build my cmake project (simple hello world DNN) generated with STM32CubeMX and TFlite Micro runtime (application template), I get a lot of linker errors:

[build] C:/ST/STM32CubeCLT_1.15.1/GNU-tools-for-STM32/bin/../lib/gcc/arm-none-eabi/12.3.1/../../../../arm-none-eabi/bin/ld.exe: CMakeFiles/ai_app2_tfruntime.dir/X-CUBE-AI/App/app_x-cube-ai.c.obj: in function `ai_boostrap':

[build] C:/projects/ml/st_trials/ai_app2_tfruntime/X-CUBE-AI/App/app_x-cube-ai.c:77: undefined reference to `tflm_c_create'

[build] C:/ST/STM32CubeCLT_1.15.1/GNU-tools-for-STM32/bin/../lib/gcc/arm-none-eabi/12.3.1/../../../../arm-none-eabi/bin/ld.exe: C:/projects/ml/st_trials/ai_app2_tfruntime/X-CUBE-AI/App/app_x-cube-ai.c:87: undefined reference to `tflm_c_operators_size'

[build] C:/ST/STM32CubeCLT_1.15.1/GNU-tools-for-STM32/bin/../lib/gcc/arm-none-eabi/12.3.1/../../../../arm-none-eabi/bin/ld.exe: C:/projects/ml/st_trials/ai_app2_tfruntime/X-CUBE-AI/App/app_x-cube-ai.c:88: undefined reference to `tflm_c_tensors_size'

[...lots of other errors...]

All of them seem related to the declarations in tflm_c.h and the linker not finding the C++ definition in tflm_c.cc.

If I add tflm_c.cc as source (in cmake/stm32cubemx/CMakeLists.txt), I get a lot of other linker errors:

[build] C:/ST/STM32CubeCLT_1.15.1/GNU-tools-for-STM32/bin/../lib/gcc/arm-none-eabi/12.3.1/../../../../arm-none-eabi/bin/ld.exe: CMakeFiles/ai_app2_tfruntime.dir/X-CUBE-AI/App/tflm_c.cc.obj: in function `AbortImpl()':

[build] C:/projects/ml/st_trials/ai_app2_tfruntime/cmake/stm32cubemx/../../Middlewares/tensorflow/tensorflow/lite/kernels/op_macros.h:25: undefined reference to `DebugLog'

[build] C:/ST/STM32CubeCLT_1.15.1/GNU-tools-for-STM32/bin/../lib/gcc/arm-none-eabi/12.3.1/../../../../arm-none-eabi/bin/ld.exe: CMakeFiles/ai_app2_tfruntime.dir/X-CUBE-AI/App/tflm_c.cc.obj: in function `tflite::MicroErrorReporter::~MicroErrorReporter()':

[build] C:/projects/ml/st_trials/ai_app2_tfruntime/cmake/stm32cubemx/../../Middlewares/tensorflow/tensorflow/lite/micro/tflite_bridge/micro_error_reporter.h:28: undefined reference to `vtable for tflite::MicroErrorReporter'

[...lots of other errors...]

How can I solve this?

N-B: I use the toolchain that comes with CubeCLT version 1.15.1.

Thanks in advance, Best regards

Jérémie

[fauvarque.daniel]

Here is what worked for me 

Create a project with STM32CubeMX 6.12 add AI, your tflite network and select tflite runtime

Go to the Project Manager tab, enter a project name and select "cmake" as IDE

Generate code

in the generated folder edit cmake/stm32cubemx/CMakeLists.txt

replace all  ../../../ by ../../

Add all the missing c++ files in target_sources (all the files ending with .cc) it should be in the form of 

../../Middlewares/tensorflow/tensorflow/lite/core/api/error_reporter.cc

for example if you are in a shell you can do

$ cd cmake/stm32cubemx/

$ find ../.. -name \*.cc >out

and them add the content of out into the target_sources

add the path of arm-none-eabi-gcc to your PATH

then lauch cmake and make

cmake CMakeLists.txt

make

Regards