NRF54L15 FLPR Setup - FLPR not running

RE: NRF54L15 FLPR Setup - FLPR not running

Vidar Berg — Thu, 30 Apr 2026 11:29:00 GMT

I am glad to see that you were able to solve the issue, thank you for the update. I was just working on a demo using FLPR with MCUboot which may be relevant if you are looking to add DFU support later: https://github.com/vidarbe/ncs_hello_world_with_flpr

RE: NRF54L15 FLPR Setup - FLPR not running

Mark G. — Thu, 30 Apr 2026 10:21:35 GMT

I will close this issue. The solution is to also choose the "Nrf54l15-M33" settings in Ozone to flash the FLPR-RiscV Application. It just needs to be copied to the correct location in the RRAM in my case. And then make sure to set the proper PC and SC in the Ozone script.

It is easy to get it wrong. Since it is "tempting" to choose the "Nrf54l15-RV" configuration, which does not work.

RE: NRF54L15 FLPR Setup - FLPR not running

Mark G. — Wed, 29 Apr 2026 11:51:17 GMT

Ok i am now pretty certain that the build process itself is fine. It is just the flashing via

west flash --skip-rebuild

Seems to do something correctly for the FLPR core that SEGGER Ozone does not.

RE: NRF54L15 FLPR Setup - FLPR not running

Mark G. — Wed, 29 Apr 2026 09:44:40 GMT

Ok so I got i little further. When I build and flash using

west build -p -b csot/nrf54l15/cpuapp -S nordic-flpr --no-sysbuild
west flash

west build -p -b csot/nrf54l15/cpuflpr --no-sysbuild
west flash

So something during the build / flash process is different then when i use my my raw CMakeLists and flashing without the "west - wrapper"