IR: Log to USB on failure. Optionally log on success #92
Description
The idea is for systems that are headless, if they fail, then have a way to get that information out easily. Also optionally have a log on success (hidden behind a runtime option, e.g. IR_LOG_ALL IR_LOG_AUDIT, etc.). Both of these would the normal output to the tmp files but then copy them after the fact to USB. LOG_AUDIT would create a timestamped entry in a file that contains the boot time, operations that were performed, etc. so that it can be logged every time a unit was booted. Note that this would rely on the RTC working for a full timestamp, but if not, it would still record the number of boots basically.