nRF54L15 ARM and RISC V

First project to use both cores of the nRF54L15

Hardware

The following hardware is used for the project:

• Nordic nRF54L15 PDK

Firmware

Tools

• Set up your Zephyr development tooling. For details refer to the Zephyr Getting Started Guide
• For flashing via west, set up nrf-command-line tools available here from nRF.

Initialization

# prepare workspace
mkdir nRF54L15
python3 -m venv --copies nRF54L15/.venv
source nRF54L15/.venv/bin/activate
# install west
python3 -m pip install west

# initialize workspace
west init -m https://github.com/SvenHaedrich/hello_dualcore --mr main nRF54L15
cd nRF54L15
west update

# install additional tools
python3 -m pip install pyelftools
python3 -m pip install intelhex

Separate Builds with Merge on Silicon

You can run two seperate builds. This will give you two HEX files.

west build --board nrf54l15pdk/nrf54l15/cpuapp --build-dir build-app -S nordic-flpr hello_dualcore
west build --board nrf54l15pdk/nrf54l15/cpuflpr --build-dir build-risc hello_dualcore

Use the nrf Programmer tool to merge the output and flash the result to your device. You can observe the two serial ports via the devkits´s USB connection. These show up as /dev/ttyACM0 and /dev/ttyACM1. You get the following output on these ports:

*** Booting nRF Connect SDK v2.7.0-5cb85570ca43 ***
*** Using Zephyr OS v3.6.99-100befc70c74 ***
Hello World! nrf54l15pdk@0.3.0/nrf54l15/cpuapp

and

*** Booting nRF Connect SDK v2.7.0-5cb85570ca43 ***
*** Using Zephyr OS v3.6.99-100befc70c74 ***
Hello World! nrf54l15pdk@0.3.0/nrf54l15/cpuflpr

Sysbuild

The canonical way two handle this situation is to use Zephyr's sysbuild. The sysbuild will need some additional configuration files. In this sample the sysbuild is driven by sysbuild.cmake. As of now that attempt files, there seems to be something rotten in the RISC V device tree configuration.

west build --board nrf54l15pdk/nrf54l15/cpuapp -S nordic-flpr --sysbuild hello_dualcore -- -DSB_CONFIG_RISCV_CPU='"nrf54l15pdk/nrf54l15/cpuflpr"'

gives, at some point:

-- Found devicetree overlay: /home/sven_gcx/Repos/nRF54L15/zephyr/snippets/nordic-flpr/nordic-flpr.overlay
devicetree error: 'execution-memory' is marked as required in 'properties:' in /home/sven_gcx/Repos/nRF54L15/zephyr/dts/bindings/riscv/nordic,nrf-vpr-coprocessor.yaml, but does not appear in <Node /soc/peripheral@50000000/vpr@4c000 in '/home/sven_gcx/Repos/nRF54L15/zephyr/misc/empty_file.c'>
-- In: /home/sven_gcx/Repos/nRF54L15/build/riscv/zephyr, command: /home/sven_gcx/Repos/nRF54L15/.venv/bin/python;/home/sven_gcx/Repos/nRF54L15/zephyr/scripts/dts/gen_defines.py;--dts;/home/sven_gcx/Repos/nRF54L15/build/riscv/zephyr/zephyr.dts.pre;--dtc-flags;'';--bindings-dirs;/home/sven_gcx/Repos/nRF54L15/nrf/dts/bindings;/home/sven_gcx/Repos/nRF54L15/zephyr/dts/bindings;--header-out;/home/sven_gcx/Repos/nRF54L15/build/riscv/zephyr/include/generated/devicetree_generated.h.new;--dts-out;/home/sven_gcx/Repos/nRF54L15/build/riscv/zephyr/zephyr.dts.new;--edt-pickle-out;/home/sven_gcx/Repos/nRF54L15/build/riscv/zephyr/edt.pickle;--vendor-prefixes;/home/sven_gcx/Repos/nRF54L15/nrf/dts/bindings/vendor-prefixes.txt;--vendor-prefixes;/home/sven_gcx/Repos/nRF54L15/zephyr/dts/bindings/vendor-prefixes.txt
CMake Error at /home/sven_gcx/Repos/nRF54L15/zephyr/cmake/modules/dts.cmake:296 (message):
  gen_defines.py failed with return code: 1