Since 26 June 2019 Lauterbach implemented a new screen driver model to support different GUI frameworks. The GUI specific software parts were split out into shared libraries (t32screen*).

If one of the following shared object files  

• t32screencde.so (for UNIX)

•  t32screenqt4.so (for UNIX)  

•  t32screenqt5.so (for UNIX)

• t32screenwin.dll (for Windows)

or a related shared library is missing, TRACE32 PowerView displays an error message.

Background information

Customers use a wide range of Linux distributions, from very old to the latest versions. This creates compatibility challenges with the QT graphical user interface (GUI) framework used by TRACE32® software:

• Older Linux distributions do not support QT version 5.x.

• Newer Linux distributions no longer support QT version 4.x.

Since QT version 4.x and QT version 5.x are incompatible, additional considerations arise. Furthermore, some customers still prefer using the MOTIF GUI on Linux.

To address this, Lauterbach previously provided two executable variants for each target architecture on Linux:

• t32m*: Supported the MOTIF GUI.

• t32m*-qt: Supported the QT version 4.x GUI.

However, with the latest Linux distributions dropping support for QT version 4.x, introducing a third executable for QT version 5.x (t32m*-qt5) would have been impractical and increased installation size.

To streamline support for different GUI frameworks, Lauterbach implemented in 2019 a more efficient mechanism:

• GUI-specific components are now packaged as shared libraries (.so files on Linux, .dll files on Windows).

• When TRACE32® starts, it dynamically searches for these shared libraries and attempts to load them.

If no shared library is found, TRACE32® reports an error and aborts operation.

Shared Library Loading Sequence on Linux:
TRACE32® attempts to load the following shared libraries in order:

1. t32screenqt5.so – Supports QT version 5.x (only available for 64-bit Linux).

2. t32screenqt4.so – Supports QT version 4.x.

3. t32screencde.so – Supports the MOTIF GUI.

The software uses the first library it can successfully load.

This mechanism enables auto-detection of supported GUI frameworks:

• If QT version 5.x is not supported, t32screenqt5.so fails to load, and TRACE32® tries t32screenqt4.so.

• If QT version 4.x is also unsupported, TRACE32® tries t32screencde.so.

• If none of these libraries can be loaded, TRACE32® displays an error message and aborts.

Shared Library Loading on Windows
A similar mechanism is used on Windows. TRACE32® looks for the shared library:

• t32screenwin.dll

If this DLL is not found, TRACE32® aborts with an error message box.

Customizing GUI Library Loading in TRACE32

By default, TRACE32® searches for the required shared library (DLL/SO files) in the same directory as the executable.

On Linux, TRACE32® will attempt to load GUI shared libraries in the following order:

1. t32screenqt5.so

2. t32screenqt4.so

3. t32screencde.so

You can override this behavior by setting an environment variable called T32SCREENSO.

• The variable defines a colon-separated (:) list of shared libraries (SO files) that TRACE32® should attempt to load in sequence.

• If TRACE32® cannot load any of the specified libraries, it will abort operation.

Examples for Linux

Using a Relative Path

export T32SCREENSO=t32screencde.so:t32screenqt4.so

With this configuration:

1. TRACE32® will first try to load t32screencde.so from the directory where the executable resides.

2. If unsuccessful, it will try t32screenqt4.so from the same directory.

3. If both attempts fail, TRACE32® will terminate.

Using an Absolute Path

export T32SCREENSO=/opt/t32/t32screenqt4.so

With this configuration:

1. TRACE32® will try to load /opt/t32/t32screenqt4.so (ignoring the executable's location).

2. If the file cannot be loaded, TRACE32® will terminate.

Example for Windows

Using an Absolute Path

SET T32SCREENSO=C:\my_programs\t32dll\t32screenwin.dll

With this configuration:

1. TRACE32® will attempt to load C:\my_programs\t32dll\t32screenwin.dll (ignoring the executable's location).

2. If the file cannot be loaded, TRACE32® will terminate.

Troubleshooting

If TRACE32® is unable to load a DLL (Windows) or an .so file (Linux), it displays an error message clearly indicating which files it attempted to load.

• For UNIX-like operating systems:
  This information is printed to the standard error (stderr). To view the error message, you must start TRACE32® from a terminal or shell command line.

• For successful starts:
  If TRACE32® starts without issues, you can use the following command in the TRACE32® command line to verify which shared library was loaded:

  VERSION.SOFTWARE

  This command opens a window displaying the details of the loaded DLL or .so file.

Linux-Specific Hints

Missing System Shared Libraries

TRACE32® relies on system shared libraries to render its GUI on Linux. To use a specific GUI framework, ensure the required shared libraries are installed on your system.

To identify missing shared libraries, use the ldd command-line tool.

Example 1: Diagnosing a missing library for QT5
If t32screenqt5.so cannot be loaded, run:

ldd t32screenqt5.so  

This will display diagnostic output indicating which libraries are missing.

Example 2: Diagnosing a missing library for QT4
If the QT4 system shared libraries are not installed, running:

ldd t32screenqt4.so  

might yield output like this:

linux-vdso.so.1 (0x00007ffe52d2e000) 
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f47cd768000) 
libQtGui.so.4 => not found 
...

Finding the Missing Package

Once you identify the missing library, determine the package name that provides it. Below are common libraries and their associated GUI frameworks:

• MOTIF: libXm.so.4

• QT4: libQtGui.so.4

• QT5: libQt5Widgets.so.5

The method to find the package depends on your Linux distribution:

• APT-based distributions (Debian, Ubuntu, Linux Mint, etc.):
  Install apt-file if not already installed:

  sudo apt install apt-file  
  apt-file find <library>  

• Zypper-based distributions (SUSE Linux, etc.):

  zypper search -f <library> 

• YUM-based distributions (Older Red Hat, Fedora, etc.):

  yum whatprovides '*/<library>'  

• DNF-based distributions (Recent Red Hat, Fedora, etc.):

  dnf provides <library>  

• Pacman-based distributions (Arch Linux, Manjaro, etc.):

  pacman -Fs <library>  

• Gentoo:
  Search for the package online.

MOTIF-Related Considerations

• Previously, Linux provided two executables per architecture:

  • t32m* (MOTIF GUI)

  • t32m*-qt (QT GUI)

• With the new shared library mechanism, t32m*-qt has been replaced by a small bash script. If you update TRACE32® by copying only the t32m*-qt file (without copying t32m*), the script will invoke the old software version using the MOTIF GUI.

Hint: Always copy both t32m* (without -qt) and t32m*-qt during updates to avoid this issue.

To enforce the use of the MOTIF GUI, set the following environment variable:

export T32SCREENSO=t32screencde.so  

To make this permanent, add the line above to your ~/.bashrc file.

Deprecated Executable Warning

If you encounter a warning like:

Warning: starting /home/testuser/t32/bin/pc_linux64/t32marm-qt is deprecated, see https://www.lauterbach.com/3737  

update your start script or command line to replace t32m*-qt with t32m* (without -qt).