Morse code kernel panics [LWN.net]

Here's one feature which didn't get in before the freeze: morse code kernel panics, recently updated to 2.5 by Tomas Szepe. With this patch, a 2.5 kernel which goes into a panic state will blink out the panic message in morse code using the keyboard LEDs. Possible future enhancements include audio output using the PC speaker or a sound card. One developer has mentioned the possibility of having a nearby machine with a microphone to detect and decode the encoded panic message.

One might well be tempted to object that the number of people clamoring for this feature has been relatively small. But there is actually a serious side to this patch. It is well known that production Linux systems never panic, but if, someday, a box were to be struck by a cosmic ray and go down, its owner might like to know about it. Preferably before the "where has your site been this last week?" mail starts to show up. The morse code patch could, with a bit of work, be the beginning of a more general panic notification feature. It could be useful, even if you hope you never actually make use of it.

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Morse code kernel panics

Posted Feb 6, 2003 4:08 UTC (Thu) by egoforth (guest, #2351) [Link]

Before people make fun of such an idea, I have encountered hardware which does something similar. With an HP ZX6000 (an Itanium2 box), there is a small port on the front of the case. When there's a hardware problem, in addition to the blinking LEDs (which diagnose to a subsytem), you can hold a phone up to the port and it will chirp to the listening system on the other end to diagnose to the component level. Unfortunately, I have had to use this more than once on this particular piece of hardware....

Morse code kernel panics

Posted Feb 6, 2003 5:40 UTC (Thu) by cpeterso (guest, #305) [Link]

My cable modem has various blinken lights. In the user manual, there is a glossary of all the long/short blink patterns to help you diagnose network problems. It's helpful on a monitor-less modem (but I always need to dig around to find the user manual). This seems pointless on a Linux box with a monitor, but if a headless system this might be useful.

Morse code kernel panics

Posted Feb 6, 2003 19:28 UTC (Thu) by emkey (guest, #144) [Link]

Back in the days of the Sun 3's and older Sun had something called a "Cylon" on the back of many of their systems. Basically it was a series of seven or so small red LED's. When things were going well they would cycle much like the Cylon's helmits on the old BattleStar Galactica series. When the system was haevily loaded the cycling would slow down. When the system crashed different LED's would remain lit depending on what the problem was. Later on Sun switched to using the keyboard LED's in a similer way, but it was never anywhere near as cool or useful.

Sun's "cylon" lights were just another method of doing what this patch does, and from that experience I'm pretty sure this patch would be a useful one to have incorporated.

LWN question

Posted Feb 6, 2003 6:40 UTC (Thu) by Ross (subscriber, #4065) [Link]

Why isn't there a "Comments" link at the bottom of the "Patches and updates"
portion of the Kernel development section? I had a question about Rusty's latest
module patch.

Morse code kernel panics

Posted Feb 6, 2003 16:41 UTC (Thu) by BrucePerens (guest, #2510) [Link]

No-Code International supports use of Morse Code in systems, but we feel that the Linux certification exam should not include a test on comprehension of Morse Code by ear, regardless of the speed.

Bruce

[only radio hams will understand this joke :-) ]

Morse code kernel panics

Posted Feb 14, 2003 18:07 UTC (Fri) by Baylink (subscriber, #755) [Link]

Hey!

I had to learn it; and damnit, they will too!

(ex-KA1FJX)

Spelling nit

Posted Feb 6, 2003 22:37 UTC (Thu) by chicks (guest, #3877) [Link]

non-capitalization of proper names is quite common on the internet and in my humble opinion it's not such a bad thing. :) it's not that we don't know any better, it's just that little letters are underappreciated.

Cheap cpu coolers

Posted Feb 6, 2003 18:23 UTC (Thu) by kruemelmo (subscriber, #8279) [Link]

Since cheap cpu coolers already play tunes in case of failure, a paniced Linux kernel should probably come up with something more sophisticated than morse code. Or, it should at least quote (morse) some good literature.

NATO "Phonetic Alphabet" in under 50K

Posted Feb 7, 2003 2:35 UTC (Fri) by tmattox (subscriber, #4169) [Link]

My advisor wrote a public domain standalone program just for this sort of thing for headless beowulf cluster nodes to call for help:

http://aggregate.org/HELPME/

It can read out error messages using the NATO "Phonetic Alphabet" through the PC speaker, as well as Morse code. (Alpha, Bravo, Charlie, ...) The entire totaly standalong executable is under 50K bytes, and can be even smaller with some work.

-- Tim