1.. zephyr:code-sample:: number_crunching 2 :name: Number crunching using optimized library 3 4 Set up and use different backends for complex math operations. 5 6Overview 7******** 8 9Number crunching sample does vector operations, Fast Fourier Transformation and filtering. 10This example demonstrates how to include a proprietary static library into the Zephyr build system. 11The library is in an out of tree location. 12 13To use this sample, with an out of tree library, one needs to define an environment variable 14``LIB_LOCATION``. 15In that location, one needs to have a ``CMakeLists.txt`` that defines: 16 17.. code-block:: cmake 18 19 # Link with the external 3rd party library. 20 set(LIB_DIR "lib" CACHE STRING "") 21 set(INCLUDE_DIR "include" CACHE STRING "") 22 set(LIB_NAME "proprietary_lib.a" CACHE STRING "") 23 24If the environment variable ``LIB_LOCATION`` is not defined, a default Zephyr API is used instead. 25 26This sample executes some mathematical functions that can be used for audio processing like 27filtering (Fast Fourier Transform (FFT)) or echo cancellation (Least Mean Square (LMS) filter 28algorithm). 29 30The sample has: 31 32- :file:`main.c`: calls the generic math functions; 33- :file:`math_ops.c`: executes the math functions, computes the cycles it took to execute and checks the output; 34- :file:`cmsis_dsp_wrapper.c`: calls the exact math functions from CMSIS-DSP if :kconfig:option:`CONFIG_CMSIS_DSP` is defined and ``LIB_LOCATION`` is not defined; 35- :file:`nature_dsp_wrapper`: if ``LIB_LOCATION`` is defined and points to an out of tree location where that NatureDSP lib and headers can be found, calls the exact math functions from NatureDSP library. 36 37If one wants to include a new backend it needs to create a new wrapper for that library or backend. 38 39Requirements 40************ 41 42CMSIS-DSP is an optional module and needs to be added explicitly to your Zephyr workspace: 43 44.. code-block:: shell 45 46 west config manifest.project-filter -- +cmsis-dsp 47 west update cmsis-dsp 48 49NatureDSP can be taken from Github: https://github.com/foss-xtensa/ndsplib-hifi4/tree/main. 50To compile it use the steps described in the repository. 51 52Building and Running 53********************* 54 55To build the sample with ``west`` for the ``imx8mp_evk/mimx8ml8/adsp``, which is the HiFi4 DSP core 56from NXP i.MX8M Plus board, run: 57 58.. zephyr-app-commands:: 59 :zephyr-app: samples/boards/nxp/adsp/number_crunching/ 60 :board: imx8mp_evk/mimx8ml8/adsp 61 :goals: build run 62 :compact: 63 64An output example, for CMSIS-DSP is: 65 66.. code-block:: console 67 68 *** Booting Zephyr OS build v3.7.0-2815-g9018e424d7a1 *** 69 70 Proprietary library example! 71 72 [Library Test] == Vector Sum test == 73 [Backend] CMSIS-DSP module 74 [Library Test] Vector Sum takes 6886 cycles 75 [Library Test] == Vector Sum test end with 1 == 76 77 [Library Test] == Vector power sum test == 78 [Backend] CMSIS-DSP module 79 [Library Test] Vector power sum takes 6659 cycles 80 [Library Test] == Vector power sum test end with 1 == 81 82 [Library Test] == Vector power sum test == 83 [Backend] CMSIS-DSP module 84 [Library Test] Vector power sum takes 3681 cycles 85 [Library Test] == Vector power sum test end == 86 87 [Library Test] == Fast Fourier Transform on Real Data test == 88 [Backend] CMSIS-DSP module 89 [Library Test] Fast Fourier Transform on Real Data takes 67956 cycles 90 [Library Test] == Fast Fourier Transform on Real Data test end == 91 92 [Library Test] == Bi-quad Real Block IIR test == 93 [Backend] CMSIS-DSP module 94 [Library Test] Bi-quad Real Block IIR takes 506702 cycles 95 [Library Test] == Bi-quad Real Block IIR end == 96 97 [Library Test] == Least Mean Square (LMS) Filter for Real Data test == 98 [Backend] CMSIS-DSP module 99 [Library Test] Least Mean Square (LMS) Filter for Real Data test takes 184792 cycles 100 [Library Test] == Least Mean Square (LMS) Filter for Real Data test end == 101 102For NatureDSP, the output looks like this: 103 104.. code-block:: console 105 106 *** Booting Zephyr OS build v3.7.0-2815-g9018e424d7a1 *** 107 108 Proprietary library example! 109 110 [Library Test] == Vector Sum test == 111 [Backend] NatureDSP library 112 [Library Test] Vector Sum takes 3829 cycles 113 [Library Test] == Vector Sum test end with 1 == 114 115 [Library Test] == Vector power sum test == 116 [Backend] NatureDSP library 117 [Library Test] Vector power sum takes 2432 cycles 118 [Library Test] == Vector power sum test end with 1 == 119 120 [Library Test] == Vector power sum test == 121 [Backend] NatureDSP library 122 [Library Test] Vector power sum takes 2594 cycles 123 [Library Test] == Vector power sum test end == 124 125 [Library Test] == Fast Fourier Transform on Real Data test == 126 [Backend] NatureDSP library 127 [Library Test] Fast Fourier Transform on Real Data takes 3338 cycles 128 [Library Test] == Fast Fourier Transform on Real Data test end == 129 130 [Library Test] == Bi-quad Real Block IIR test == 131 [Backend] NatureDSP library 132 [Library Test] Bi-quad Real Block IIR takes 13501 cycles 133 [Library Test] == Bi-quad Real Block IIR end == 134 135 [Library Test] == Least Mean Square (LMS) Filter for Real Data test == 136 [Backend] NatureDSP library 137 [Backend] NatureDSP library 138 [Library Test] Least Mean Square (LMS) Filter for Real Data test takes 7724 cycles 139 [Library Test] == Least Mean Square (LMS) Filter for Real Data test end == 140
