sysbuild: support application CMakePresets.json files with sysbuild

[tejlmand]

This commit provides a CMakePresets.json which includes the sample's CMakePresets.json file.

west build is extended to set APP_DIR in environment when sysbuild is used. This allows sysbuild's CMakePresets.json to include the sample's presets file.

Alternative to: #95047

[pdgendt]

Needs a rebase

[tejlmand]

@benedekkupper ptal.

[57300]

Re #95047 (comment)

As a minor (not blocking) note then this PR only makes it possible to use presets together with west, and thus does not support pure CMake / projects which are not using west, but have custom tools.

Actually, it already works with pure CMake if you define APP_DIR in your environment beforehand.

In fact, I would suggest updating sysbuild itself so it could pick up the same environment variable:

zephyr/share/sysbuild/CMakeLists.txt

Lines 7 to 9 in 3232354

	if(NOT DEFINED APP_DIR)
	message(FATAL_ERROR "No main application specified")
	endif()

The standard, non-west sysbuild invocation could then change from:

cmake -Bbuild ~/ncs/zephyr/share/sysbuild -DAPP_DIR=$PWD

to:

APP_DIR=$PWD cmake -Bbuild ~/ncs/zephyr/share/sysbuild

and let the --preset argument be added without hassle.

Not blocking this PR, but that would be another benefit to this approach.

[benedekkupper]

This PR is a lot cleaner, and I'd prefer to do it this way than #95047, however it doesn't solve the relative path translation issue: the application's presets file is full of such variables (e.g. "BOARD_ROOT": "${sourceParentDir}/", "CONF_FILE": "${sourceDir}/prj_release.conf"), since these resolve to sysbuild's directory and not to the app's, the build fails.

[tejlmand]

As a minor (not blocking) note then this PR only makes it possible to use presets together with west, and thus does not support pure CMake / projects which are not using west, but have custom tools.

Actually, it already works with pure CMake if you define APP_DIR in your environment beforehand.

@57300 That was a comment to #95047.
#95047 does not support pure CMake sysbuild as described in https://docs.zephyrproject.org/latest/build/sysbuild/index.html#building-with-sysbuild

cmake -Bbuild -GNinja -DBOARD=reel_board -DAPP_DIR=samples/hello_world share/sysbuild

because #95047 relies on west build to copy the CMakePresets.json file.

But PR#96609 supports both west build ... -- --preset=<name> as well as APP_DIR=<path-to-app> cmake ... -DAPP_DIR=<path-to-app> --preset=<name>

In fact, I would suggest updating sysbuild itself so it could pick up the same environment variable:

Yes, I did consider that as well, but wanted some feedback from @benedekkupper first regarding the alternative approach before doing wider changes.

[57300]

That was a comment to #95047.

I see, I didn't realize that "this PR" was referring to #95047. I'm sorry for misreading your original comment.

In fact, I would suggest updating sysbuild itself so it could pick up the same environment variable:

Yes, I did consider that as well, but wanted some feedback from benedekkupper first regarding the alternative approach before doing wider changes.

Good to know. I guess this is essentially a work in progress and I jumped in too early.

[benedekkupper]

I could make this patch work in my environment, by relying on ${fileDir} instead of ${sourceDir} and co. in the application's CMakePresets.json, and while not ideal, this is the optimal solution that I can see for this problem at the moment.

[tejlmand]

I could make this patch work in my environment, by relying on ${fileDir} instead of ${sourceDir} and co. in the application's CMakePresets.json, and while not ideal, this is the optimal solution that I can see for this problem at the moment.

@benedekkupper Thanks for testing it out and provide feedback.
I think fileDir is a good replacement for sourceDir for the current state.

Will cleanup the PR and add some doc notes on regarding this.
Marking draft for the time being.

[tejlmand]

Good to know. I guess this is essentially a work in progress and I jumped in too early.

@57300 and @benedekkupper ptal, it's fully ready now 🙂

[benedekkupper]

typo "preser" -> preset

[tejlmand]

Fixed

[benedekkupper]

I would rephrase this a bit, e.g.: As sysbuild changes the top-level cmake project to its own directory, the cmake presets are parsed from there, the application's presets are included from this file verbatim. Therefore relative paths, and macros resolving relative to the source directory will not work as expected, but as relative to share/sysbuild. The ${fileDir} macro can be used to create portable paths relative to the application's directory.

[tejlmand]

Thanks for the suggestion.
Applied.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[benedekkupper]

LGTM :)