[Profiling] Integrate rv-profile tool into X-HEEP

[Vincenzo-Petrolo]

Hi,
This PR has the goal to bring rv-profile into X-HEEP.

Graphic example of a FlameGraph

This is an example of what is generated after running the FFT example in X-HEEP.

Features

• All the CPUs currently supported by X-HEEP are also supported by rv-profile
• Generation of interactive FlameGraphs. Use the example here

TODO

Among the things missing I see (feel free to edit and add more):

• Adding a page to the doc

[davidmallasen]

Hello @Vincenzo-Petrolo. Could you move profile to util/profile? I prefer not having a new top-level directory. Then, you can also keep the script in the same profile directory to avoid having it scattered in two different places

[Vincenzo-Petrolo]

Hi @davidmallasen, I did it.

Please let me know If anything else needs to be addressed.

[davidmallasen]

Thanks @Vincenzo-Petrolo. Then I think we're just missing the docs page documenting it. I would suggest adding a profiling page under how to. If you need more guidance let me know

[Vincenzo-Petrolo]

Hi @davidmallasen, I added the page "Profiling" under "How To" 👍🏻.

[davidmallasen]

Hello @Vincenzo-Petrolo. I tried running this with the information from the docs and I run into this:

usage: rv_profile [-h] --elf ELF --fst FST --cfg CFG [--out OUT]
rv_profile: error: argument --fst: expected one argument

So I believe something is missing. For example, I didn't know if I had to add a specific compile/execution flag or what simulator I had to use. I tried compiling and running the example_matadd with verilator.

[Vincenzo-Petrolo]

Hi @davidmallasen,

I replicated your issue, it is because wal-lang (the module I use to analyze waveforms) only accepts FSTs if they have .fst extension in the name. I fixed it with last commit.

Verilator should be fine for simulation.

[davidmallasen]

Hello @Vincenzo-Petrolo. It is still not working for me.

⠏ Reading the waveforms
>>>>> WAL Runtime error! <<<<<

Is it enough to just rename the vcd to fst? I imagine they are two different formats