Debugging aid for a Neo Freerunner problem.
This happens after a while using SHR.
After it happens, sdcard access is compromised (IO error on non-cached files).
If the OS is being executed from the card, the system is now in deadlock (no filesystem).
If the OS is in flash, then then problem goes away after a suspend and resume, but reoccurs later.
The SDcard is a Kingston 8GB uSdhc.