Add Zephyr Support in segger SystemView

[zephyrbot]

Reported by Anas Nashif:

"SGGER SystemView is a real-time recording and visualization tool that reveals the true runtime behavior of an application, going far deeper than the insight provided by debuggers. This is particularly effective when developing and working with complex systems comprising multiple threads and interrupts: SystemView can ensure a system performs as designed, can track down inefficiencies, and show unintended interactions and resource conflicts."

https://www.segger.com/systemview.html?p=1731

Follow documentation in https://www.segger.com/downloads/free_tools/UM08027_SystemView.pdf

and add zephyr support in SystemView for visualisation of kernel threads and objects.

(Imported from Jira ZEP-1463)

[zephyrbot]

by Leandro Pereira:

I began taking a closer look at this today. This seems doable without too much effort.

I'll proceed by adding a CONFIG_PROFILING_HOOKS, and sprinke calls to functions such as profile_hook_thread_spawn(), profile_hook_thread_cancel(), etc -- Zephyr would only provide the prototypes for these functions in the kernel.

I'll then write a sample application and implement those functions using SEGGER's SystemView implementation.

There are two reasons I prefer to have this separation: first, I don't want to litter the kernel with SEGGER_*() calls, and second, I want also to take a look into other real time profiling software (SeggerView is proprietary and we can't add new features to it should we need).

The major problem right now is due to bandwidth: UART might not be fast enough; however, we now have a stable IP stack, which could be used instead... I'll begin writing the prototypes.

[zephyrbot]

by Anas Nashif:

Leandro Pereira ACK, re bacndwidth, look at segger rtt which is already in zephyr and being used on NRF platforms. RTT = Real Time Transfer

Also agree that we need to look at other open-source tools.

Carles Cufi any feedback on this?

[zephyrbot]

by Anas Nashif:

https://www.segger.com/jlink-rtt.html

[zephyrbot]

by Leandro Pereira:

I'm changing direction here slightly: instead of adding hook functions, I'm going to use the kernel event logger feature. I didn't know this was a thing; found about it while looking at the interrupt handling code. Not all of the events required/desired by SystemView are supported, and some lack some information, but it can be extended, hopefully without breaking the API.

[zephyrbot]

by Leandro Pereira:

I have some code for this, although I can't just provide the official SeggerView implementation as the license is not an standard OSI license. The RTT has the same license and is already included in Zephyr, so this is unlikely to be an issue

I was not able to test, though, because I wasn't able to use JLink to connect to the (seemingly supported) FRDM-K64F board, so that live capture could be performed by SystemView. It's possible to use the tool to analyze recorded data, so I might do that by using gdb and a Python script.

[zephyrbot]

by Leandro Pereira:

• sysview.png (size: 118996)

[zephyrbot]

by Leandro Pereira:

Finally got it working. I've attached an screenshot of the tool capturing data from a sample application. Some things are clearly wrong, and the default polling frequency of 4KHz isn't enough (RTT is dropping a lot of frames). But at least the tool recognizes Zephyr.

I'm going to clean up the code and figure out what's wrong with the values and send the patches for review.

[zephyrbot]

by Anas Nashif:

great :)

[zephyrbot]

by Mark Linkmeyer:

manoj subbarao , do you have someone who can verify this?

[zephyrbot]

by savinay dharmappa:

Tested system view on frdmk64f board. It is working as expected.

[zephyrbot]

by savinay dharmappa:

Testing of systemview support in zephyr is done