Add some detail on hotspot/flamegraph usage

[Fomys]

When working with embedded Linux systems, debugging from a different device often requires additional setup. Trainees may encounter challenges when using tools like hotspot and flamegraph, which need proper configuration to work with a different sysroot.

To address this, I suggest enhancing the training material by adding brief yet helpful information about the necessary configurations. Specifically, Slide 206 could be updated to include a small section on setting up hotspot for embedded debugging. The added content might look like this:

Quick Tip: Configuring Hotspot for Embedded Debugging
When using hotspot, you can customize settings in the "Settings/Unwinding" menu. Adjust these options to match your environment:

• Sysroot: Set the path to your sysroot directory (for example output/target with buildroot).
• Objdump: Specify the location of objdump (for example output/host/.... with buildroot)
• Target Architecture: Select or configure the architecture (e.g., ARM, MIPS) for proper debugging.

This addition provides trainees with a quick reference without disrupting the flow of the lecture. They can revisit this hint later when setting up their tools.

[Tropicao]

Note for the actual implementation: there are some additional settings that should be considered to properly cover the embedded use case

• set the application path
• set the kallsyms (and so it needs some instructions about how to fetch it from the target: cp /proc/kallsyms /tmp/kallsyms, and then scp it onto the host)