How can I add a `main` symbol entry back to a load_image ELF? (MSP432 target)

Nathan Vander Wilt

I was able to combine a boot loader with an application firmware into a single image by adding one project (the bootloader) as a dependency and adding this as a post-build step to the other project (the app):

"${CG_TOOL_ROOT}/bin/armhex.exe" "${PROJECT_ROOT}/app-boot-combo.cmd" "${build_var:/${REF_PROJECT_2_NAME}/BuildArtifactFilePath}" "${BuildArtifactFileName}" --outfile="${BuildArtifactFileBaseName}.combo.out"

The command file is:

--load_image
--load_image:combine_sections=false
--image
 
ROMS {
    Bootloader  : origin = 0x00000000, length = 0x00008000
    Application : origin = 0x00008000, length = 0x00038000
}

Now I would like CCS to use that combined "load image" when I debug my app. I discovered that if instead of combining into `--outfile="${BuildArtifactFileBaseName}.combo.out"` that I can just use `--outfile="${BuildArtifactFileName}"` and it overwrites the original app-only out file with the combined file and that CCS will flash the combined one automatically which is a great start.

However, when I do this I get errors from the debugger:

CORTEX_M4_0: AutoRun: Target not run as the symbol "main" is not defined
CORTEX_M4_0: AutoRun: Target not run as the symbol "main" is not defined

I noticed in the ARM Assembly Language Tools User's Guide (spnu118y) section 12.6.2 Load Image Characteristics that it says "The file is not marked executable and does not contain an entry point".

How can I add the "main" symbol back in so that the CCS debugger won't be updset?

over 5 years ago

0 Ki over 5 years ago

TI__Guru**** 486221 points

Hello,

It is not mandatory to have a 'main' symbol in your program. The issue you are running into is the debugger "auto-run to symbol" feature where the default label is "main". You can disable the feature or specify a new symbol in the debugger options:

https://software-dl.ti.com/ccs/esd/documents/users_guide/ccs_debug-main.html#auto-run-and-launch-options

Thanks

0 Nathan Vander Wilt over 5 years ago in reply to Ki

Intellectual 340 points

Unfortunately I'm finding out it's a bit more than that. When I use the load_image I cannot set any breakpoints and it says "No code is associated with C:\…\myfile.cpp, line X in any loaded symbols"

So I think really what I need is not just "main" but all the symbols from at least my app image to get their information copied over to the load image. How can I do this?

0 Ki over 5 years ago in reply to Nathan Vander Wilt

TI__Guru**** 486221 points

It sounds like you are missing some of the debug symbols. Based on your original post, it looks like you combined two executables. I'm not too familiar with the technique you used but I assume that the symbols from both *.out files should be in the one combined file? If you open the Modules view, do you see all the expected symbols?

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How can I add a `main` symbol entry back to a load_image ELF? (MSP432 target)