Resolving SIMATIC IOT2000 HelloWorld Build Missing Executable Fix

Problem Overview

When following the official SIMATIC IOT2000 - Getting Started procedure with Eclipse IDE for C/C++ Developers Neon.2 (4.6.2) and the Siemens-provided Yocto/Poky SDK, the incremental build completes without errors and reports Build Finished (took 6s.565ms), yet the release folder contains only the intermediate object file example.o. The expected final executable HelloWorld is never produced, so the SCP/SFTP transfer dialog described in the Getting Started manual step 4 cannot resolve a valid host path and the OK button stays disabled. This behavior is reproducible on Windows 10 and on Linux guest VMs using the same workspace.

The problem is not in the toolchain itself; the cross-compiler i586-poky-linux-g++ and the --sysroot path resolve correctly. The defect is in the Eclipse CDT build configuration that the Getting Started wizard generates: the compile command retains the GCC stop-after-compile flag in both the global tool settings and the per-file command pattern, and the linker step is configured with the wrong artifact extension.

Affected Environment and SDK Layout

The error reproduces against the canonical Siemens IOT2000 SDK tree. The exact paths used in the failing build are listed below; if your installation differs only by drive letter or username, the same remediation applies.

The SDK is generated by the Yocto Project and provides a self-contained sysroot with the GNU C++ 5.3.0 runtime, the libmraa userspace GPIO/I2C/SPI library and the libupm sensor repository. Reference the official Siemens Industry Online Support portal for the IOT2000 Getting Started entry ID 109741705 and the matching SDK image.

Build Console Analysis

The console output observed during the failing build is reproduced below, normalized for line wrapping. The exact sequence is critical for diagnosis.

20:23:11 **** Incremental Build of configuration IOT2000 Release for project HelloWorld ****
Info: Internal Builder is used for build
i586-poky-linux-g++ "-IC:\00_Data\SDK_Destination_Folder\sysroots\i586-nlp-32-poky-linux\usr\include"
                     "-IC:\00_Data\SDK_Destination_Folder\sysroots\i586-nlp-32-poky-linux\usr\include\c++\5.3.0"
                     "-IC:\00_Data\SDK_Destination_Folder\sysroots\i586-nlp-32-poky-linux\usr\include\c++\5.3.0\i586-poky-linux"
                     "-IC:\00_Data\SDK_Destination_Folder\sysroots\i586-nlp-32-poky-linux\usr\include\mraa"
                     "-IC:\00_Data\SDK_Destination_Folder\sysroots\i586-nlp-32-poky-linux\usr\include\upm"
                     -O0 -g3 -Wall -c -fmessage-length=0 -m32 -march=i586 -c -ffunction-sections -fdata-sections
                     "--sysroot=C:\00_Data\SDK_Destination_Folder\sysroots\i586-nlp-32-poky-linux"
                     -o example.o "..\example.cpp"

i586-poky-linux-g++ -lmraa -fno-use-linker-plugin
                     "--sysroot=C:\00_Data\SDK_Destination_Folder\sysroots\i586-nlp-32-poky-linux"
                     -o HelloWorld example.o

20:23:17 Build Finished (took 6s.565ms)

Notice that the compile invocation contains the flag -c twice and a second -c on the same line. Although GCC tolerates duplicate -c, the second occurrence is a strong indicator that the Getting Started wizard's per-file command pattern was edited and the global C/C++ Build > Settings > GCC C++ Compiler command pattern was left at its default ${COMMAND} ${FLAGS} ${OUTPUT_FLAG} ${OUTPUT_PREFIX} ${INPUTS}, which already appends -c. Meanwhile, the linker invocation appears to run correctly. The actual root cause lies in a different setting covered in the next section.

Root Cause: Why example.o Is Produced Without HelloWorld

Three configuration defects, individually or combined, prevent Eclipse CDT's Internal Builder from generating the final executable:

1. Wrong artifact extension in the linker step. Project Properties > C/C++ Build > Settings > GCC C++ Linker > Output file. The Getting Started template leaves ${OUTPUT_PREFIX}${OUTPUT} in the command pattern but sets the artifact extension to o instead of leaving it blank (or specifying an empty extension). The Internal Builder therefore writes HelloWorld.o, which then collides with the compile artifact name and is either overwritten or skipped.
2. Per-file compile command pattern overrides the global pattern. Project Properties > C/C++ Build > Settings > GCC C++ Compiler > Command line pattern. If a custom pattern that strips -c is inserted here, the Internal Builder treats every translation unit as a link candidate and never finalizes an executable.
3. Missing linker step on the build invocation. Project Properties > C/C++ Build > Tool Chain Editor. The "Current toolchain" must be "Cross GCC". If the wizard accidentally selected "No Toolchain" the link step is suppressed entirely.

Diagnosis Procedure

Confirm each defect before applying the fix:

1. In Eclipse, right-click the HelloWorld project and select Properties.
2. Navigate to C/C++ Build > Tool Chain Editor. Confirm Current toolchain is Cross GCC and Current builder is Gnu Make Builder or CDT Internal Builder with the toolchain fields populated.
3. Open C/C++ Build > Settings > Cross Settings. Confirm Prefix is i586-poky-linux- and Path points to the Yocto SDK environment script directory (typically C:\00_Data\SDK_Destination_Folder\sysroots\i586-nlp-32-poky-linux\usr\bin\..\..\environment-setup-i586-nlp-32-poky-linux on Windows).
4. Open C/C++ Build > Settings > GCC C++ Compiler. Inspect the Command line pattern field. It must read exactly:
   ${COMMAND} ${FLAGS} ${OUTPUT_FLAG} ${OUTPUT_PREFIX} ${INPUTS}
5. Open C/C++ Build > Settings > GCC C++ Linker. Inspect Command line pattern (should be ${COMMAND} ${FLAGS} ${OUTPUT_FLAG} ${OUTPUT_PREFIX} ${INPUTS}) and Output file (should be ${OUTPUT_PREFIX}${OUTPUT} with extension blank).
6. Click Project > Clean..., enable Clean all projects, click OK, then Project > Build Project. Repeat the console inspection.

Solution A: Correct the Cross-Compiler Command Pattern

The duplicate -c in the console output shows that an additional flag string was injected into the command pattern. Reset it:

1. Project Properties > C/C++ Build > Settings > Cross Settings > Command: set to g++.
2. Project Properties > C/C++ Build > Settings > GCC C++ Compiler: set the Command line pattern to:
   ${COMMAND} ${FLAGS} ${OUTPUT_FLAG} ${OUTPUT_PREFIX} ${INPUTS}
3. Project Properties > C/C++ Build > Settings > GCC C++ Compiler > Miscellaneous: clear the Other flags field if it contains stray -c, -shared, or -fPIC entries not required by the HelloWorld example.
4. Click Apply and Close.

Solution B: Configure Linker Output Artifact

This is the most common fix for the symptom where only example.o remains in the release folder.

1. Project Properties > C/C++ Build > Settings > GCC C++ Linker.
2. In Expert settings, click Output file. Replace the existing value with:
   ${OUTPUT_PREFIX}${OUTPUT}
3. Confirm the Command line pattern field reads:
   ${COMMAND} ${FLAGS} ${OUTPUT_FLAG} ${OUTPUT_PREFIX} ${INPUTS}
4. Still under GCC C++ Linker > Libraries, add mraa to Libraries (-l). The Getting Started template sets this via -lmraa; if the linker output command line shows no -l tokens, add the library here instead of via Other flags.
5. Open the GCC C++ Linker > Miscellaneous subnode and ensure the Linker flags field contains -fno-use-linker-plugin only if required by the Yocto toolchain version in use; remove duplicate --sysroot entries.

Solution C: Force Full Rebuild After Clean

If Solutions A and B are in place but the executable still does not appear, force the Internal Builder to relink by removing every intermediate artifact:

1. Close Eclipse.
2. In Windows Explorer, navigate to the workspace folder (typically C:\Users\<user>\workspace\HelloWorld).
3. Delete the entire IOT2000 Release subfolder and any sibling IOT2000 Debug folder.
4. Reopen Eclipse, right-click the project, and select Project > Build Project (do not use Build All; on Neon.2 CDT this can re-trigger incremental caching).
5. Inspect the console. The expected sequence is now exactly two lines: one compile invocation, one link invocation.

Deploying HelloWorld to the SIMATIC IOT2000

Once the release folder contains the executable HelloWorld, proceed with the deployment step from the Getting Started manual:

1. In the Eclipse Remote Systems Explorer (RSE) perspective, expand the SIMATIC IOT2000 node and connect via SSH.
2. Right-click My Home (or the target folder such as /home/iot/) and select Upload Files....
3. In the host field, browse to C:\Users\<user>\workspace\HelloWorld\IOT2000 Release\HelloWorld and confirm the OK button activates.
4. On the target, open a serial console or SSH session and execute:
   chmod +x /home/iot/HelloWorld
/home/iot/HelloWorld

Verification Checklist

Troubleshooting Matrix

FAQ