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ARMCLANG: "System and Thread Viewer" is empty debugging RTXv4

Information in this knowledgebase article applies to:

  • MDK v5.x
  • Keil RTXv4.x (based on CMSIS RTOSv1)
  • ARMCLANG v6.x Compiler


I managed to build my project using RTXv4.x library with ARMCLANG v6.x compiler. But when I tried debugging it using "System and Thread Viewer" in the µVision debug session, "System and Thread Viewer" stays empty.

"System and Thread Viewer" works fine with all threads etc. shown up, when I build the same project using ARMCC v5.x compiler.

How can I make "System and Thread Viewer" work for a project using RTXv4.x built with ARMCLANG v6.x compiler?


The debug feature "System and Thread Viewer" looks for and relies on some specific data symbols of RTXv4.x to show OS-awareness debug info. Different compilers might generate different symbols names or even remove some of these symbols.

As a workaround solution here, one of these two options can be applied to your project:

  1. Add -fno-data-sections to Options for Target - C/C++ (AC6) - Misc Controls in µVision
  2. Or add --keep=os_tmr to Options for Target - Linker - Misc Controls in µVision

However, note that building a project using RTXv4.x with ARMCLANG v6.x compiler is not officially supported or well tested. It is suggested to build a project using RTXv4.x with ARMCC v5.x compiler.


Last Reviewed: Wednesday, October 10, 2018

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