Hi grzegorzkonopko
Answering your questions:
1. Actually the fsl_debug_console are already thread safe, if you check the code in DbgConsole_Printf() in our latest SDK, you will find some APIs like LOG_TAKE_MUTEX_SEMAPHORE_NONBLOCKING. Any case, if you want DbgConsole_Printf() with interrupt, you can look into the macro DEBUG_CONSOLE_TRANSFER_NON_BLOCKING.
3. MCUXpresso SDK is the latest SDK drivers for kinetis devices, so I would recommend you this.
Hope this could help
Have a great day,
TIC
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