### Author:  [@aphardt](https://discourse.cmake.org/u/aphardt)
#### Post date: [July 10, 2020, 3:21pm UTC](https://discourse.cmake.org/t/cmake-cortex-m-multitarget-build/1536/1 "2020-07-10T15:21:05Z")
Hi
Im trying to achieve a cmake build environment where i can build multiple targets (binaries) at once.
cmake and make/ninja actually run successfully, but the generated ELF’s somehow do not run at all. When i run them with a segger debug session, they seem not to be able to map gdb addresses to source files.
what i also notice is that targetA and B are identical in size, even if they do not execute the same in the main program.
i found a lot of good inputs on github for cmake, both for either A.) cortex-M or B.) multiple-target builds, but never combined. i assume i have some configuration error.
Could someone help me out? If needed, i can also provide the entire project as a zip.
thank you!
== the main project (CMAKELISTS) =====================
set(CMAKE\_SYSTEM\_NAME Generic)
set(CMAKE\_SYSTEM\_PROCESSOR arm)
set(CMAKE\_ASM\_COMPILER arm-none-eabi-gcc)
set(CMAKE\_C\_COMPILER arm-none-eabi-gcc)
set(CMAKE\_CXX\_COMPILER arm-none-eabi-g++)
set(CMAKE\_EXE\_LINKER\_FLAGS “-specs=nano.specs -Wl,–gc-sections” CACHE INTERNAL “”)
set(CMAKE\_ASM\_COMPILER\_ID GNU)
set(CMAKE\_C\_COMPILER\_ID GNU)
set(CMAKE\_CXX\_COMPILER\_ID GNU)
set(CMAKE\_ASM\_COMPILER\_FORCED TRUE)
set(CMAKE\_C\_COMPILER\_FORCED TRUE)
set(CMAKE\_CXX\_COMPILER\_FORCED TRUE)
enable\_language (ASM)
set (CMAKE\_ASM\_FLAGS “${CFLAGS} -x assembler-with-cpp”)
set (CPU\_OPTIONS -mthumb -mcpu=cortex-m3)
cmake\_minimum\_required (VERSION 3.17.3)
project (main-project)
set (CMAKE\_ASM\_FLAGS\_DEBUG “-g”)
set (CMAKE\_C\_FLAGS\_DEBUG “-Og -g -UNDEBUG -DDEBUG”)
set (CMAKE\_CXX\_FLAGS\_DEBUG “-Og -g -UNDEBUG -DDEBUG”)
set (CMAKE\_ASM\_FLAGS\_RELEASE “-g”)
set (CMAKE\_C\_FLAGS\_RELEASE “-Og -g -UNDEBUG -DDEBUG”)
set (CMAKE\_CXX\_FLAGS\_RELEASE “-Og -g -UNDEBUG -DDEBUG”)
add\_definitions( -DEFM32GG380F1024 )
add\_definitions( -DDEBUG\_EFM )
add\_subdirectory (libraries/math\_lib\_1)
add\_subdirectory (libraries/math\_lib\_2)
add\_subdirectory (libraries/efm32)
add\_subdirectory (libraries/dummy\_interface)
add\_subdirectory (targetA)
add\_subdirectory (targetB)
add\_subdirectory (targetZ)
== TARGET A ========================================
# identical to B and Z just different main program
project (targetA)
include\_directories( ${PROJECT\_NAME}
${CMAKE\_SOURCE\_DIR}
${CMAKE\_SOURCE\_DIR}/targetA
)
link\_directories( ${PROJECT\_NAME}
${CMAKE\_SOURCE\_DIR}
)
add\_executable ( ${PROJECT\_NAME}
main
dummy
targetA\_interface
)
set ( LINKER\_SCRIPT “libraries/linker/targetA\_linker.ld” )
target\_link\_libraries ( ${PROJECT\_NAME}
PRIVATE
${CPU\_OPTIONS}
-T${LINKER\_SCRIPT}
-Wl,–gc-sections
-nostartfiles
-Xlinker
-Map=${PROJECT\_NAME}.map
m
gcc
math\_lib\_1
math\_lib\_2
efm32
dummy\_interface
)
set\_target\_properties( ${PROJECT\_NAME}
PROPERTIES
SUFFIX “.elf”
)
=== LIB =======================================
add\_library ( efm32
startup\_efm32gg
system\_efm32gg)
target\_include\_directories ( efm32
PUBLIC ${CMAKE\_CURRENT\_SOURCE\_DIR})
---
### Author:  [@kyle.edwards](https://discourse.cmake.org/u/kyle.edwards)
#### Post date: [July 10, 2020, 3:33pm UTC](https://discourse.cmake.org/t/cmake-cortex-m-multitarget-build/1536/2 "2020-07-10T15:33:01Z")
First off, I would not suggest setting `CMAKE__COMPILER`, or in fact anything above your `enable_language()`, inside your project file. Those should instead be set via a [CMake toolchain file](https://cmake.org/cmake/help/latest/manual/cmake-toolchains.7.html).
Second, you can get rid of the `enable_language()` call and change `project(main-project)` to `project(main-project ASM)`. This will also skip enabling C and C++ (assuming they’re not needed of course.)
Third, your linker options:
```auto
${CPU_OPTIONS}
-T${LINKER_SCRIPT}
-Wl,–gc-sections
-nostartfiles
-Xlinker
-Map=${PROJECT_NAME}.map
```
should be in a `target_link_options()` call instead.
Fourth, what’s going on here?
```cmake
add_executable ( ${PROJECT_NAME}
main
dummy
targetA_interface
)
```
These look like target names rather than source files, which makes me think they should be linked with `target_link_libraries()` instead. Does your program have any source files, or is it simply combining libraries?
And finally, I would use `objdump -s` and `objdump -S` on your output to see if any code is getting compiled in at all.
---
### Author:  [@aphardt](https://discourse.cmake.org/u/aphardt)
#### Post date: [July 10, 2020, 3:41pm UTC](https://discourse.cmake.org/t/cmake-cortex-m-multitarget-build/1536/3 "2020-07-10T15:41:45Z")
> [@kyle.edwards](#):
>
> `target_link_options`
A.)
`target_link_options` then it wont link anylonger at all, ninja stops execution at some point
B.)
```auto
add_executable ( ${PROJECT_NAME}
main
dummy
targetA_interface
)
```
those are 3 target specific source files (\*.cpp)
I would like to share my project with you, but the website does not allow newbie-users to attach data. can i somehow else publish my project?
---
### Author:  [@kyle.edwards](https://discourse.cmake.org/u/kyle.edwards)
#### Post date: [July 10, 2020, 3:48pm UTC](https://discourse.cmake.org/t/cmake-cortex-m-multitarget-build/1536/4 "2020-07-10T15:48:09Z")
How about starting a small repository on GitHub? You can of course strip out any proprietary data you don’t want to share.
---
### Author:  [@aphardt](https://discourse.cmake.org/u/aphardt)
#### Post date: [July 10, 2020, 3:51pm UTC](https://discourse.cmake.org/t/cmake-cortex-m-multitarget-build/1536/5 "2020-07-10T15:51:58Z")
Ok ill do the github repository later, good idea. but for now i dont have an account, so ill share it with wetransfer
(offline)
---
### Author:  [@kyle.edwards](https://discourse.cmake.org/u/kyle.edwards)
#### Post date: [July 10, 2020, 3:57pm UTC](https://discourse.cmake.org/t/cmake-cortex-m-multitarget-build/1536/6 "2020-07-10T15:57:35Z")
Thanks. I just took a look at your project.
I would suggest making the `.cpp` extension in `add_executable()` (and `add_library()`) explicit for the sake of readability.
When I said to use `target_link_options()`, I didn’t mean to move _everything_ into `target_link_options()`, just things that are not libraries. So it would look something like:
```cmake
target_link_options ( ${PROJECT_NAME}
PRIVATE
${CPU_OPTIONS}
-T${LINKER_SCRIPT}
-Wl,–gc-sections
-nostartfiles
-Xlinker
-Map=${PROJECT_NAME}.map
)
target_link_libraries(${PROJECT_NAME}
m
gcc
math_lib_1
math_lib_2
efm32
dummy_interface
)
```
---
### Author:  [@aphardt](https://discourse.cmake.org/u/aphardt)
#### Post date: [July 10, 2020, 4:05pm UTC](https://discourse.cmake.org/t/cmake-cortex-m-multitarget-build/1536/7 "2020-07-10T16:05:45Z")
ok thanks. i applied your suggestions. its still building suggessfully, but the final binary is the same.
the objdump seems to have all functions available, so i assume everything is linked into the binary correctly (hard assumption though!)
---
### Author:  [@kyle.edwards](https://discourse.cmake.org/u/kyle.edwards)
#### Post date: [July 10, 2020, 5:23pm UTC](https://discourse.cmake.org/t/cmake-cortex-m-multitarget-build/1536/8 "2020-07-10T17:23:50Z")
One more thing… did you run CMake with `-DCMAKE_BUILD_TYPE=Debug`?
---
### Author:  [@aphardt](https://discourse.cmake.org/u/aphardt)
#### Post date: [August 7, 2020, 11:06am UTC](https://discourse.cmake.org/t/cmake-cortex-m-multitarget-build/1536/9 "2020-08-07T11:06:12Z")
The issue is it hardfaults directly after the Reset\_Handler().
I dont see whats going bad here at the moment.