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Sometimes, all what I have is a ELF/Dwarf binary, and I need to debug it. I don’t want to build it, only debug it. The NXP VS Code extension makes that possible. I simply import the binary and start debugging.

Debugging Executable

Outline

This article describes how to import an embedded ELF/Dwarf (.elf or .axf) file without project for debugging. ELF/Dwarf files are the standard binaries for targets and cross development. They include the code. They also contain debug information if it has not been stripped.

For this, I use the ‘Import’ on an executable in VS Code. After that, I can debug it right away.

Prerequisites

Install the NXP extension into VS Code (extension identifier nxpsemiconductors.mcuxpresso or https://marketplace.visualstudio.com/items?itemName=NXPSemiconductors.mcuxpresso)

Import

Click on the NXP extension icon in the side bar and use ‘Import Project‘:

Import Project

Executable

Then select ‘Executable‘:

Import Executable

Then browse to the ELF/Dwarf file you want to debug: In my case it is

c:\tmp\LPC55S16_blinky.elf

and it is detected as ‘executable’:

Executable file path

Next, I can specify a folder where VS Code can store the settings. I’m using the

c:\tmp\binary

location:

location to store the settings

Toolchain

Next I specify the toolchain which includes the GDB for debugging:

Toolchain selection

Finally, press ‘Import’:

Import

Debug

This creates an entry for the executable in the side view with a ‘debug/run’ icon I can use:

Debug Icon

MCU Selection

Using the executable the first time, I get asked about what MCU I want to use:

MCU Selection

After this: I’m debugging that executable:

Debugging Executable

Assembly Level Debugging

Based on the debug information, VS code is using the source file information present in the ELF/Dwarf file. Ideally, I have the source files available. If not, I still can debug it on assembly level instruction level:

Assembly Level Debugging

Summary

Using VS Code with the NXP MCUXpresso Extension, it is surprisingly easy to debug the binary. There’s no need to import or build project. All I need to do is point to the executable. Then, I select the toolchain for the GDB and device I want to use. This is very useful for a quick check of a binary on an embedded target board. All I need is the binary with VS Code. Then, I can start debugging it. If I have the sources available, I even can do source-level-debugging. Or I can debug on assembly instruction level.

Happy debugging 🙂

Links

• NXP VS Code MCUXpresso Extension: https://marketplace.visualstudio.com/items?itemName=NXPSemiconductors.mcuxpresso
• Dwarf files: https://en.wikipedia.org/wiki/DWARF
• Elf files: https://en.wikipedia.org/wiki/Executable_and_Linkable_Format