NCS 3.4.0 - sysbuild - custom overlay for mcuboot

[Achim Kraus]

NCS 3.4.0, sysbuild, with mcuboot enabled.

I want to use a simple custom "my.overlay" for both the app and mcuboot.

For the app it works with 

-DEXTRA_DTC_OVERLAY_FILE='my.overlay'

But for mucboot that seems not to work that easy.

-Dmcuboot_EXTRA_DTC_OVERLAY_FILE='my.overlay'

Regardless where I put that file, e.g.

<prjdir>/my.overlay

<prjdir>/sysbuild/mcuboot/my.overlay

it's not found,

... until ugly, hard to maintain "full-path" to the overlay is used,

-Dmcuboot_EXTRA_DTC_OVERLAY_FILE='C:/ncs/v3.4.0/myproj/my.overlay'

Is there an other way to use custom overlays for sysbuild, e.g. mcuboot?

(Just to mention: AI proposed a lot of things. To be frank: for something, which was that easy and clear before sysbuild, I would expect to have also a simple solution with sysbuilds.)

[Amanda Hsieh]

Hi Achim, 

You can use FILE_SUFFIX to apply custom overlay/config files as https://github.com/nrfconnect/sdk-nrf/blob/v3.4.0/samples/dfu/smp_svr sample, or use sysbuild.cmake like this: 

set(overlay "${CMAKE_CURRENT_LIST_DIR}/my.overlay")

list(APPEND EXTRA_DTC_OVERLAY_FILE ${overlay})
set(EXTRA_DTC_OVERLAY_FILE ${EXTRA_DTC_OVERLAY_FILE} CACHE INTERNAL
    "Application extra DTC overlay file" FORCE)

list(APPEND mcuboot_EXTRA_DTC_OVERLAY_FILE ${overlay})
set(mcuboot_EXTRA_DTC_OVERLAY_FILE ${mcuboot_EXTRA_DTC_OVERLAY_FILE} CACHE INTERNAL
    "Application extra DTC overlay file" FORCE)

Regards,
Amanda H.

[Achim Kraus]

As I wrote: 

Something has basically going wrong, if an easy to apply feature as an dt overlay gets hidden. 

The question is simply, why should overlay for the other sysbuild parts be that complicated?