12: 'I' if the kernel is working around a severe bug in the platform
firmware (BIOS or similar).
+ 13: 'O' if an externally-built ("out-of-tree") module has been loaded.
+
The primary reason for the 'Tainted: ' string is to tell kernel
debuggers if this is a clean kernel or if anything unusual has
occurred. Tainting is permanent: even if an offending module is