Can't debug using Segger Tunnel Server

[andrew_walsh]

Hello,

I've been trying to debug with MCUXpresso 10.3.1, using a remote Segger J-Link (on a different site); the J-Link is connected via J-Link remote server to the SEGGER Tunnel Server (6.48b, matching the firmware in the J-Link).

When I try to debug using MCUXpresso, it manages to connect to the debugger, and the attached target PCB (an IMXRT1052, if that makes any difference), but it fails with a timeout. The message is:

Remote replied unexpectedly to 'vMustReplyEmpty': timeout

I've tried adding a run command "monitor sleep 500", as suggested in a different thread, but this does not seem to make any difference. Any ideas as to how I could to deal with this?

Many thanks,

Andrew.

[ErichStyger]

Hi Andrew,

I doubt that the monitor sleep command would help, as this simply delays the server for the given amount.

Have you tried the same setup in your local network? I think your network connection adds too much delay to get it working in a reliable way. What J-Link are you using? It might be helpful to use one with an Ethernet connector (if you are using a USB based one connected to the host) and making a direct tunnel connection between the networks.

I hope this helps,

Erich

[andrew_walsh]

Hi Erich,

Thanks for getting back to me. We are using a J-Link Pro.

We started out by attempting to connect directly from MCUXpresso to a J-Link Pro on another network (using port forwarding - this approach is not secure, of course). This was not working, for reasons I'm not certain of (to be honest, I can't remember!).

In any case, I came across a statement on the Segger forums where they indicate that even a J-Link Pro (with an Ethernet interface) is only intended for use *inside* a LAN; they imply that timing problems would occur if a VPN, etc, was used. So, on reading this, I abandoned this first idea, instead using the J-Link Remote Server software, since this situation is one of Segger's stated use cases for this software.

I also tried using a remote GDB server (an idea I think I came across on your blog, possibly :-D) across our VPN, but I could not get this to work either. In this case, I had the two computers on my desk; one running the GDB server with the debugger connected, and one a laptop running MCUExpresso connected to the VPN through our guest WiFi network.

I have two reasons for wanting to do this: first a customer wants us to be able to remote debug their setup if necessary, and I soon also will have to work from home whilst leaving my dev hardware in the office, and I was hoping to avoid using Windows Remote Desktop...! Perhaps I will have to fall back to that approach...

Best regards,

Andrew.