Post build step building a Zephyr application

[kpreiss]

Hi,

We are using the nRF Connect SDK and building a Zephyr standalone application. Is there a way to add a post build step to the application CMakeLists.txt file which will run AFTER the zephyr.hex is generated?

Thanks.

[Einar Thorsrud]

Hi,

Have you looked at extra_post_build_commands? That is the closest I can think of.

[kpreiss]

No, I have not looked into this.  Are there any examples of using this with a Zephyr build?

[Einar Thorsrud]

There are quite a few example of it, I suggest you search for "extra_post_build_commands" in the SDK code base and look at some of the the CMakeLists.txt files that use it.

A more or less random example is from zephyr\boards\arm\faze\CMakeLists.txt:

set_property(GLOBAL APPEND PROPERTY extra_post_build_commands
  # Insert checksum (verified by the bootloader) into the zephyr.bin
  # and zephyr.hex images.
  COMMAND lpc_checksum -f hex ${CMAKE_BINARY_DIR}/zephyr/${KERNEL_HEX_NAME}
  COMMAND lpc_checksum -f bin ${CMAKE_BINARY_DIR}/zephyr/${KERNEL_BIN_NAME}
  )

[kpreiss]

Hi Einar,

Thank you for pointing me in the right direction.  I'm not proficient in CMake so it's been a bit of a struggle.  We have created a freestanding Zephyr project and have our own board file defined.  In the CMakeLists.txt file in the board directory I added....

# Include post build instructions from build folder.
include(${APPLICATION_CONFIG_DIR}/postbuild.cmake)

Where APPLICATION_CONFIG_DIR is the folder where the application CMakeLists.txt file exists.

Then, in my application folder I created the postbuild.cmake file with the following contents...

set(CMAKE_SREC_TOOL "../../FileTools")

# Add post-build step after final zephyr application is created.

set_property(GLOBAL APPEND PROPERTY extra_post_build_commands
COMMAND "${APPLICATION_CONFIG_DIR}/../createappbin.bat" "${CMAKE_SREC_TOOL}"
)

This runs AFTER the final zephyr elf file is created.  Putting the post build commands in a separate cmake file provides the flexibility of customizing the post build steps by application, not by board.