How to build nanopb proto sources into a zephyr_library

RE: How to build nanopb proto sources into a zephyr_library

Anthony Ambuehl — Thu, 12 Sep 2024 17:56:52 GMT

For anyone else interested in nanopb in a zephyr library here is a discussion I had on github that helped me get it working:

github.com/.../77494

RE: How to build nanopb proto sources into a zephyr_library

Vidar Berg — Tue, 27 Aug 2024 17:23:23 GMT

Thanks for the clarification. According to this commit: https://github.com/nrfconnect/sdk-zephyr/commit/86c92869d25fb85444c7b4a0de6d03b94d9c688e , it seems that you'll need to convert your 'lib' directory into a Zephyr module to create a Zephyr library. The library can then be enabled and configured in your applications.

RE: How to build nanopb proto sources into a zephyr_library

Anthony Ambuehl — Mon, 26 Aug 2024 17:24:01 GMT

I'm not asking to make nanopb a separate library, I'm trying to make the generated protobuf c files that have been implemented as multiple modular schemas into a zephyr library.

The .proto file are located in a lib/schema/schema.proto. protoc and the nanopb generator should be used to convert those files into .c and .h files located in the lib/schema and those .c and .h files should be added into the build from the lib/schema/CMakeLists.txt and compiled into a zephyr_library()

the nanopb examples add the .proto files from the application folder which does not scale well when there are multiple application folders, such as when there is a manufacturing test application and multiple applications for different markets/products.

RE: How to build nanopb proto sources into a zephyr_library

Vidar Berg — Mon, 26 Aug 2024 09:04:24 GMT

It’s not clear to me why you would build nanopb as a separate library rather than using the integrated Zephyr module as demonstrated in the sample application. When using the module, the generated source files will be placed in the build folder. Are you looking to have the generated source files copied to your project source directory instead, or is there other functionality missing in the Zephyr integration of nanopb?

If you want to build a separate linkable library from your project, you can use the External Library sample as a reference.

RE: How to build nanopb proto sources into a zephyr_library

Anthony Ambuehl — Fri, 23 Aug 2024 16:03:02 GMT

The issue isn't with configuring the build, Kconfig and prj.conf handles that just fine. I"m trying to figure out the cmake parts of the system, which I'm as experienced with.

The nanopb common files need to be added into the project somewhere, probably in the app cmake, and then in the library folder the optional proto files need to be converted into .c and .h files and then those files compiled into a library.

Perhaps someone could suggest a better forum for me to get help on this?

RE: How to build nanopb proto sources into a zephyr_library

Vidar Berg — Fri, 23 Aug 2024 14:11:34 GMT

Hello,

I don't have that much experience with Protobuf, but wouldn't it be sufficient if you could conditionally select the *.proto file during compilation? Below is a demo sample I created based on the nanopb project that selects the *.proto file based on the Kconfig configuration (CONFIG_SAMPLE_PB_PROD_A or CONFIG_SAMPLE_PB_PROD_B).

Project

devzone.nordicsemi.com/.../nanopb_5F00_332011.zip

Build command

$ west build -b <target board> -- -DCONFIG_SAMPLE_PB_PROD_A

Best regards,

Vidar