hello Matt.
You want to connect FRDM-KL25 with PE OpenSDA interface on Linux.
I use Windows7, there is no problem for me to do it from my side. Just for your reference.
First please check which debug interface do you work with ? please check it in Device manager. for example, here is my FRDM-KL25 interface. I use P&E OpenSDA.

If your system can not well recognize the board, please download PemicroLinuxDrivers_2012_09_06.tar (for linux)for manual install from above link. (Optional, in the case windows can’t recognize the interface)
http://www.pemicro.com/Opensda/
after P&E OpenSDA well installing, I suggest you:
1. remove current launch configurations in debug configuration to avoid old association.
2. relaunch debugger, it will force IDE check all the possible interface connections. then set connection.
see attached video for both of the points I am talking with.
I also attach the P&E OpenSDA firmware I am using.
Have a great day,
Jennie Zhang
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