How to use CMSIS DSP library on NRF5340?

[squwal]

Hi all, i want to use CMSIS DSP library for vector/matrix computation.

In NRF connect SDK, there is a "nRF CMSIS DSP examples solution" in the dashboard, however it fails after build solution:

Building ‘arm_matrix_example’ from solution ‘nRF CMSIS-DSP Samples’ in configuration ‘Debug’
1> Linking arm_matrix_example.elf
1>
1> Diagnostics:
1> error: relocation R_ARM_THM_JUMP24 to non-function symbol afterInitialize at .init+20
1> error: relocation R_ARM_THM_CALL to Arm-mode function not supported on this core, at .init+20 to afterInitialize
1> error: See wiki.segger.com/Correct_typing_of_Thumb_functions for help on correcting this
1> error: call from .init made to afterInitialize but afterInitialize is a symbol without the low bit set
1> error: call from .init made to afterInitialize but afterInitialize is a symbol without the low bit set
1> error: call from .init made to afterInitialize but afterInitialize is a symbol without the low bit set
1> error: call from .init made to afterInitialize but afterInitialize is a symbol without the low bit set
1> error: call from .init made to afterInitialize but afterInitialize is a symbol without the low bit set
1> error: undefined symbol: main
Build failed

How can i fix these errors, or how to use the CMSIS DSP library?

Any help will be appreciated!

  

[Carl Richard]

Hi, Squwal!

I can't seem to find any sample named "nRF CMSIS-DSP Samples". Could you please inform me of the sample path as well as what version of the nRF Connect SDK you are using?

Best regards,
Carl Richard

[squwal]

nRF Connect SDK v1.4.99-dev1, SEGGER v5.30a, nRF CMSIS-DSP Samples in  C:\Users\User\Nordic\SEGGER Embedded Studio\v3\packages\nRF\Project\Example 

[Carl Richard]

Hi again! 

Those examples are not a part of the nRF Connect SDK, but included parts of the Segger Embedded Studio nordic edition.

For CMSIS DSP in NCS I suggest that you check out the cmsis_dsp tests located under <zephyr_root>\zephyr\tests\lib\cmsis_dsp. They should work for the nRF5340 and give insight on how the library can be used.

Best regrds,
Carl Richard

[squwal]

Thank you Carl! I have found the examples and successfully built it.  And there is a question that, should i need to do some extra work to enable the FPU?  In SES menu Project->configure nRF SDK Project-> Floating Point Options-> Enable Floating Point Unit is unchecked, shoud i need to turn it on manully or somthing else?

[Carl Richard]

Hi! 

My pleasure. Good to hear that it works!

In order to enable FPU you must enable it through the configuration, as you describe in your comment. I believe that should be enough!

Best regards,
Carl Richard