CoreMark

The sample demonstrates how to run the CoreMark® benchmark to evaluate the performance of a core. To get started with CoreMark integration in nRF Connect SDK, see CoreMark integration.

Requirements

The sample supports the following development kits:

Hardware platforms

PCA

Board name

Board target

nRF54L15 PDK

PCA10156

nrf54l15pdk

nrf54l15pdk/nrf54l15/cpuapp

nRF54H20 DK

PCA10175

nrf54h20dk

nrf54h20dk/nrf54h20/cpuapp

nRF5340 DK

PCA10095

nrf5340dk

nrf5340dk/nrf5340/cpuapp

nRF52 DK

PCA10040

nrf52dk

nrf52dk/nrf52832

nRF52840 DK

PCA10056

nrf52840dk

nrf52840dk/nrf52840

Overview

The sample runs the CoreMark benchmark on the target CPU. CoreMark evaluates the CPU efficiency by performing different algorithms, such as state machine, CRC calculation, matrix manipulation, and list processing (find and sort).

To run the CoreMark benchmark on the preferred core, press the corresponding button. For the button assignment, see the User interface section. When the benchmark has completed, you can press the same button to restart it. If you want to run the sample upon startup, enable the CONFIG_APP_MODE_FLASH_AND_RUN Kconfig option.

User interface

Each target CPU has an assigned button responsible for starting the benchmark and LED that indicates the test in progress state:

Button 1:

Start the benchmark run on the application core.

Button 2:

Start the benchmark run on the network or radio core.

Button 3:

Start the benchmark run on the PPR core.

LED 1:

Indicates test in progress on the application core.

LED 2:

Indicates test in progress on the network or radio core.

LED 3:

Indicates test in progress on the PPR core.

Configuration

See Configuring and building an application for information about how to permanently or temporarily change the configuration.

CoreMark runs tests multiple times. You can define the number of iterations using the CONFIG_COREMARK_ITERATIONS Kconfig option. By default, the iteration quantity is set to the minimum time required for valid results, which is 10 seconds.

Additional configuration

Check and configure the following configuration options that are used by the sample:

Run types and data sizes

CoreMark has the following predefined run types and data sizes that are used for data algorithms:

You can also specify a custom CONFIG_COREMARK_DATA_SIZE value and submit your results by following the rules from the CoreMark GitHub repository. Make sure that when setting the CONFIG_COREMARK_DATA_SIZE Kconfig option the required memory space is available.

Memory allocation methods

You can select the following memory allocation methods:

Multithread mode

CoreMark can also be executed in multithread mode. To specify a number of threads, use the CONFIG_COREMARK_THREADS_NUMBER Kconfig option. In multithread mode, CoreMark is executed in all threads simultaneously. Each thread runs number of iterations equal to CONFIG_COREMARK_ITERATIONS. By default, the CONFIG_TIMESLICE_SIZE Kconfig option is set to 10 ms, which imitates RTOS multithread usage. However, in the final report, the thread execution is combined. In the multithread mode, the CONFIG_COREMARK_DATA_SIZE Kconfig option is allocated for each thread separately. Only the CONFIG_COREMARK_MEMORY_METHOD_STACK and CONFIG_COREMARK_MEMORY_METHOD_MALLOC memory methods can be used with multiple threads. In case of the CONFIG_COREMARK_MEMORY_METHOD_STACK Kconfig option, the data for all threads is allocated to the main thread stack.

Configuration options

Check and configure the following Kconfig options:

CONFIG_APP_MODE_FLASH_AND_RUN - Start CoreMark sample automatically after flashing

If enabled, CoreMark starts execution immediately after the CPU starts up. It also disables LEDs and buttons. Otherwise, it will wait for the button press.

Note

The CONFIG_APP_MODE_FLASH_AND_RUN Kconfig option is always enabled for the PPR core. This core does not use buttons.

SB_CONFIG_APP_CPUNET_RUN - Enable execution for the network core or the radio core

Enable the benchmark execution for the network core for targets with the nRF53 Series SoCs, and for the radio core on targets with the nRF54H20 SoCs.

SB_CONFIG_APP_CPUPPR_RUN - Enable execution for the PPR core

Enable the benchmark execution also for the PPR core for targets with the nRF54H20 SoCs.

Note

PPR code is run from MRAM with the execution in place (XIP) method. You must use the nordic-ppr-xip snippet for the application core to be able to boot the PPR core. Use the build argument coremark_SNIPPET=nordic-ppr-xip. To build the sample with the execution for the PPR core enabled, run the following command:

west build -b nrf54h20dk/nrf54h20/cpuapp -- -DSB_CONFIG_APP_CPUNET_RUN=n -DSB_CONFIG_APP_CPUPPR_RUN=y -Dcoremark_SNIPPET=nordic-ppr-xip

Building and running

When running the benchmark, an extra build flag (CONFIG_COMPILER_OPT) is set to -O3 to achieve the best CoreMark results.

This sample can be found under samples/benchmarks/coremark in the nRF Connect SDK folder structure.

To build the sample, follow the instructions in Configuring and building an application for your preferred building environment. See also Programming an application for programming steps and Testing and optimization for general information about testing and debugging in the nRF Connect SDK.

Note

In the nRF repositories, building with sysbuild is enabled by default.

After flashing, messages describing the benchmark state will appear in the console.

Testing

After programming the sample to your development kit, complete the following steps to test it:

  1. Connect to the kit with a terminal emulator (for example, nRF Connect Serial Terminal). See Testing and optimization for the required settings and steps.

  2. Reset your development kit.

  3. To start the test, press the button assigned to the respective core. For button assignment, refer to the User interface section.

    All target cores work independently from each other, and it is possible to run the benchmark on several cores simultaneously. Measurements running on a core are indicated by the corresponding LED. If the CONFIG_APP_MODE_FLASH_AND_RUN Kconfig option is enabled, the measurement will launch automatically on all available cores when starting the application. In CONFIG_APP_MODE_FLASH_AND_RUN mode LEDs and buttons are not used.

  4. Wait for all measurements to complete. By default, the test takes approximately 11-13 seconds.

  5. Wait for the console output for all tested cores. The results will be similar to the following example:

    *** Booting Zephyr OS build bf606fc00ec1  ***
    [00:00:00.502,166] <inf> app: Coremark sample for nrf52dk/nrf52832. Call address: 00007fa1
    [00:00:00.502,197] <inf> app: Press Push button switch 0 to start the test ...
    [00:00:14.483,764] <inf> app: Push button switch 0 pressed!
    [00:00:14.511,627] <inf> app: Coremark started!
    [00:00:14.511,627] <inf> app: CPU FREQ: 64000000 Hz
    [00:00:14.511,627] <inf> app: (threads: 1, data size: 2000; iterations: 2000)
    
    2K performance run parameters for coremark.
    CoreMark Size    : 666
    Total ticks      : 401312
    Total time (secs): 12.247070
    Iterations/Sec   : 163.304366
    Iterations       : 2000
    Compiler version : GCC10.3.0
    Compiler flags   : -O3 + see compiler flags added by Zephyr
    Memory location  : STACK
    seedcrc          : 0xe9f5
    [0]crclist       : 0xe714
    [0]crcmatrix     : 0x1fd7
    [0]crcstate      : 0x8e3a
    [0]crcfinal      : 0x4983
    Correct operation validated. See README.md for run and reporting rules.
    CoreMark 1.0 : 163.304366 / GCC10.3.0 -O3 + see compiler flags added by Zephyr / STACK
    [00:00:27.759,582] <inf> app: Coremark finished! Press Push button switch 0 to restart ...