Export the finished binary and byproducts from the build folder

[nylnx]

I want to get the finished zephyr.elf and other post-build products like map file, disassembly etc. and copy them to a different, better location. Unfortunately there seems to be no elegant solution for this. It is possible to configure all these outputs in Kconfig, including the actual name for the zephyr.elf(!), but it all just gets dumped into the build/zephyr folder, together with a whole host of temp files and other things.

The only thing that can be somewhat elegantly exported is the elf binary itself with $<TARGET_FILE:${logical_target_for_zephyr_elf}> using the undocumented ${logical_target_for_zephyr_elf}.

What have you done? Have you never thought about it, because you just didn't need it? How would you solve this?

Thanks in advance :)

[yashi]

Set CONFIG_KERNEL_BIN_NAME with a directory name.

$ grep CONFIG_KERNEL_BIN_NAME build/zephyr/.config
CONFIG_KERNEL_BIN_NAME="foo/zephyr"
$ ls build/zephyr/foo
zephyr.bin  zephyr.elf  zephyr.hex  zephyr.lst  zephyr.map  zephyr.stat

[nylnx]

I also looked at the code and haven't noticed that I could just do this. What a great find! This enables the use of the CMake install(DIRECTORY ...) command and solves this problem.

I will still file an issue about that... There should be an easy, documented way to get the output files you produce.

[nylnx]

Anyone also getting a linker error while trying this workaround:
You need to manually create the foo folder. It will not do that automatically, at least for me. Maybe @yashi had more luck with his particular setup.
This can be automated in the ZephyrBuildConfig.cmake file like this:

set(CONFIG_KERNEL_BIN_NAME "\"foo/zephyr\"" CACHE STRING "Zephyr Binary Output Name")
file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/zephyr/foo")

[yashi]

hmm. That's odd. Does the following command work for you?

$ ls
a.txt
$ cmake -E copy a.txt foo/a.txt
$ find
.
./a.txt
./foo
./foo/a.txt
$ cmake --version
cmake version 3.25.1

On my Linux development environment, cmake -E copy creates non-existing directory when specified. The doc doesn't say about a single file copy without distination directory, though.

Also, I'd rather set CONFIG_KERNEL_BIN_NAME in prj.conf, instead.

echo 'CONFIG_KERNEL_BIN_NAME="foo/zephyr"' >> prj.conf

[nylnx]

The problem is not with CMake. It's gcc/ld that doesn't support outputting to a subdirectory that doesn't exist. So zephyr.elf just doesn't even get written and everything after that just fails.

$ ls
program.c
$ gcc program.c -o bin/program
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: cannot open output file bin/program: No such file or directory
collect2: error: ld returned 1 exit status
$ mkdir bin
$ gcc program.c -o bin/program
$ ls bin
program

Your setup might be more forgiving, since this is a really arbitrary limitation...

And having the CONFIG_KERNEL_BIN_NAME in the CMake file is a deliberate choice. I don't want this to be a concern of the project itself and also my particular setup generates part of the build files, including the ZephyrBuildConfig.cmake and the installation code in the CMakeLists.txt, while prj.conf is a manually written file. So as long as I don't overwrite CONFIG_KERNEL_BIN_NAME in my project's Kconfig, my project doesn't even know it can be installed or has a different output path :)