Zephyr CMake error (No SOURCES given to target) for out of tree driver when CONFIG_BOOTLOADER_MCUBOOT is enabled

[NathanML]

Hi,

I've successfully integrated an out of tree driver using the out_of_tree_driver example in the application_development sample folder for Zephyr; it has built and ran fine up to this point.

Recently, I added DFU functionality and along the way added CONFIG_BOOTLOADER_MCUBOOT=y to my prj.conf file. Now that this is added, I get an error when trying to build the project:

MCUBoot bootloader key file: C:/Repos/ml-firmware/nRF_NCS/sdk/v1.5.0/bootloader/mcuboot/root-ec-p256.pem
-- Configuring done
CMake Error at C:/Repos/ml-firmware/nRF_NCS/sdk/v1.5.0/zephyr/cmake/extensions.cmake:416 (add_library):
  No SOURCES given to target: _out_of_tree_driver
Call Stack (most recent call first):
  C:/Repos/ml-firmware/nRF_NCS/drivers/out_of_tree_driver/zephyr/CMakeLists.txt:28 (zephyr_library_named)


CMake Generate step failed.  Build files cannot be regenerated correctly.
CMake Error at C:/Repos/ml-firmware/nRF_NCS/sdk/v1.5.0/nrf/cmake/multi_image.cmake:287 (message):
  CMake generation for mcuboot failed, aborting.  Command: 1
Call Stack (most recent call first):
  C:/Repos/ml-firmware/nRF_NCS/sdk/v1.5.0/nrf/cmake/multi_image.cmake:84 (add_child_image_from_source)
  C:/Repos/ml-firmware/nRF_NCS/sdk/v1.5.0/nrf/modules/mcuboot/CMakeLists.txt:112 (add_child_image)

As you can see, it says "No SOURCES given to target" but I do include them with the zephyr_library_sources_ifdef line in my CMakeLists.txt for the driver (and the relevant CONFIG_DRIVER is set to 'y' in my prj.conf). I'm assuming the problem has to do with the mcuboot child image being created and not inheriting everything it should from the app parent image, but I'm not sure how to solve it.

This is the code that adds my out of tree driver to my project, located in my project folder CMakeLists.txt:

list(APPEND ZEPHYR_EXTRA_MODULES
  ${CMAKE_CURRENT_SOURCE_DIR}/../drivers/out_of_tree_driver
)

And here is an excerpt of the CMakeLists.txt in that driver folder:

zephyr_include_directories(.)
zephyr_library_named("_out_of_tree_driver")
zephyr_library_sources_ifdef(CONFIG_DRIVER            out_of_tree_driver.c)

I've taken a look at section 2.2.2 titled "Modify device tree and configurations of a child image" per the NCS tutorial here, but it's not exactly what I'm looking to do. For reference I'm using NCS v1.5.0.

Thanks in advance for any help!

[NathanML]

I would also like to note that out out of tree board directory does successfully get added & works fine. It is added to the main project directory's CMakeLists with the following line, just above the attempt to add the out of tree driver:

list(APPEND BOARD_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/../)

[Øyvind]

Hello! Have you also added the CONFIG_DRIVER to your child image? It must be explicitly set in both parent image and child image. More information in the Multi Image builds chapter.

Kind regards,
Øyvind

[NathanML]

Hi Øyvind, 

Thanks for the response! I receive the following error when attempting to build with CONFIG_DRIVER=y in my parent image:

warning: attempt to assign the value 'y' to the undefined symbol DRIVER

Do you mean CONFIG_SENSOR=y?

Also, how would I set a CONFIG_XYZ for the child image, which in this case is mcuboot? From my understanding (which could be wrong), setting CONFIG_BOOTLOADER_MCUBOOT=y is what enabled the child image being built, as I don't have any specific child image build scripts in my CMakeLists.txt for the project. For reference I used the smp_srv example to get DFU working.

So I'm not sure where I could set the configuration; I imagine in CMakeLists.txt, but from the Updating the build scripts section of your provided link I'm still not clear on how to do this.

[Øyvind]

Can you please share your project?

[NathanML]

Hi,

I've attached a .zip folder containing a sample project with the basics of the project I'm implementing along with a sample driver folder that contains our external driver we're using (a modified version of the LIS2DW12). For the purposes of making the sample as simple as possible, I added an overlay file so that you can build the project for the nRF52840 development kit board.

As you can see, it builds fine when the line CONFIG_BOOTLOADER_MCUBOOT=y is commented out, but once that line is present the error we saw before occurs. The build command I used was: west build -b nrf52840dk_nrf52840 but --pristine may be needed.

sample_external_driver_project.zip

[Øyvind]

Thanks for providing the sample. I will have a look at it now.

Just to clarify, did you follow the NCS v1.2.0 tutorial or NCSv1.5.0 turoial? Sorry for not pointing this out earlier. There is a difference in how things are included in v1.5.0.

[NathanML]

Great, thanks! Yes, I followed the v1.5.0 tutorial. I look forward to hearing from you once you've had a chance to look over the sample.

[Øyvind]

Hello again, 

I was not able to finish my testing the other day. I did some testing now, and verify what you got. 

CMake Error at C:/NordicSemi/v1.5.1/zephyr/cmake/extensions.cmake:416 (add_library):
  No SOURCES given to target: lis2dw12
Call Stack (most recent call first):
  C:/Temp/Support/271083/sample/drivers/lis2dw12/zephyr/CMakeLists.txt:9 (zephyr_library_named)

Based on the last line CMakeLists.txt:9 (zephyr_library_named), I commented this line out and was able to build with CONFIG_BOOTLOADER_MCUBOOT=y

Kind regards,
Øyvind

[NathanML]

Hi,

Thanks for your response! I did some more testing in response to your discovery and it turns out that whichever driver comes first in the list(APPEND ZEPHYR_EXTRA_MODULES list is the one that can't be a named library through zephyr_library.

The project has multiple out of tree drivers, and would like each to show up as a module in my Segger IDE, so I was able to confirm that whichever driver was first in that list couldn't be named or else the project wouldn't compile.

I was able to get around this problem by creating a dummy driver, with no source or header files, that did not have zephyr_library in its CMakeLists and I included it as the first line in my list(APPEND ZEPHYR_EXTRA_MODULES list in the project CMakeLists and now the subsequent drivers successfully compile, all of them with zephyr_library included in their CMakeLists as well.

I'm not an expert in cmake so I don't know what's going on for certain, but it is strange to me that this is the case. I'd love to find a cleaner solution rather than rely on this workaround, but I'll keep it in place for now.