In SSv5 GNU Debugger (GDB) can work with external j-link and custom board. On devkits Debugger work well, but in custom board case I getting error:
Error in services launch sequence
Starting J-Link GDB Server timed out.
This might be related to a bug I found when creating a debug configuration manually. From the Simplicity IDE, please check and attach screenshots for the debug configurations being used for external j-link. So [Run] > [Debug Configurations...] select the appropriate GDB Segger J-Link Debugging configuration for your project and go to the [Debugger] tab and compare it to one for the Silicon Labs devkits. Make sure to scroll the window down as there is a setting for GDB Client Setup that might not be visible at first. Try adjusting the GDB Server Executable path and the GDB Client Setup Executable name to either match the settings for the Silicon Labs STK or else to point to the executable in your system if they are external to Simplicity Studio. This is a screenshot of what I am referring to:
Let me know if that helps or not.
In my case, for external debugger I see incorrect settings:
GDB port 2334
SWO port 2335
Telnet port 2336
I fixed it, checked all settings in all tabs, all settigs is similar with "devkits" settings. But debugging for external J-Link stiil dont work: Server timed out.
Settings screenshot in attachment
I have escalated this thread to a support case so that you can share some logs with Silicon Labs. I will send an email and continue to work with you through the support case.
In this case Alex figured out that the debug adapter firmware of the external J-Link needed to be updated to the latest version (6.7 as of this writing).