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OpenBLAS Example

Introduction to OpenBLAS

OpenBLAS is an optimized BLAS computational library distributed under the BSD license (open source). BLAS (Basic Linear Algebra Subprograms) is an application programming interface (API) standard that specifies the publication of numerical libraries for basic linear algebra operations (such as vector or matrix multiplication). OpenBLAS is a specific implementation of the BLAS standard.

In the K230 RTOS SDK, the pre-cross-compiled OpenBLAS library is included at the path src/rtsmart/libs/openblas/. Users can directly use this static library to compile their own executable programs.

Compiling the Example

This section describes how to use the pre-built OpenBLAS static library in the SDK to compile an executable program. The SDK includes 4 executable program compilation examples based on OpenBLAS (located at the path src/rtsmart/examples/3rd-party/openblas/).

Code Structure

The directory structure under this path is described as follows:

|-- openblas_cblas_saxpy            # saxpy example, implements y = alpha * x + y
|   |-- CMakeLists.txt
|   `-- openblas_cblas_saxpy.cpp
|-- openblas_cblas_sgemm            # sgemm example, implements C = alpha * A * B + beta * C
|   |-- CMakeLists.txt
|   `-- openblas_cblas_sgemm.cpp
|-- openblas_cblas_sger             # sger example, implements A = alpha * x * y^T + beta * A
|   |-- CMakeLists.txt
|   `-- openblas_cblas_sger.cpp
|-- openblas_fortran_dgemm          # Fortran interface example, implements C = alpha * A * B + beta * C
|   |-- CMakeLists.txt
|   `-- openblas_fortran_dgemm.cpp
|-- CMakeLists.txt                  # CMake configuration file
|-- build_app.sh                    # Build script
|-- cmake                           # Default CMake configuration
|   |-- Riscv64.cmake
|   `-- link.lds

Firmware Compilation

If you want to compile the example into the firmware when building the firmware, use make menuconfig in the K230 RTOS SDK root directory to configure the build options, select RT-Smart UserSpace Examples Configuration->Enable build 3rd-party examples->Enable Build OpenBlas Sample Programs, save and exit. As shown in the figure below:

The example will be compiled into the firmware at the path sdcard/app/examples/3rd-party/openblas, and you can directly flash the firmware and run it.

Example Compilation

If you only want to compile the OpenBLAS example program, you can enter src/rtsmart/examples/3rd-party/openblas and run the build_app.sh file:

./build_app.sh

After successful compilation, the src/rtsmart/examples/3rd-party/openblas/k230_bin folder contains all the compiled elf files and test files. You can copy them to the development board for testing and running.

Running Examples

openblas_cblas_saxpy

The running method and output result example are as follows:

msh /sdcard/app/examples/3rd-party/openblas>./openblas_cblas_saxpy.elf
*********************************************************
This is the result:
4 7 11 14
*********************************************************
This is the reference:
4 7 11 14
{Test PASS}.

openblas_cblas_sgemm

The running method and output result example are as follows:

msh /sdcard/app/examples/3rd-party/openblas>./openblas_cblas_sgemm.elf
*********************************************************
This is the result:
7 10 15 22
*********************************************************
This is the reference:
7 10 15 22
{Test PASS}.

openblas_cblas_sger

The running method and output result example are as follows:

msh /sdcard/app/examples/3rd-party/openblas>./openblas_cblas_sger.elf
*********************************************************
This is the result:
20 40 10 20 30 60
*********************************************************
This is the reference:
20 40 10 20 30 60
{Test PASS}.

openblas_fortran_dgemm

The running method and output result example are as follows:

msh /sdcard/app/examples/3rd-party/openblas>./openblas_fortran_dgemm.elf
m=2,n=3,k=4,alpha=1.200000,beta=0.001000,sizeofc=6
This is matrix A

1.000000 2.000000 3.000000 1.000000 2.000000 3.000000 1.000000 2.000000
This is matrix B

1.000000 2.000000 3.000000 1.000000 2.000000 3.000000 1.000000 2.000000 3.000000 1.000000 2.000000 3.000000
*********************************************************
This is the result:
16.801 18.002 18.003 16.801 15.602 22.803
*********************************************************
This is the reference:
16.801 18.002 18.003 16.801 15.602 22.803
{Test PASS}.