---

KernelTrap: Panicking in Morse Code

“Digging through the source code of a recent kernel, in the file
‘linux/drivers/char/pc_keyb.c’, above the definition for the
function ‘panic_blink’, one reads the following comment:

/* Tell the user who may be running in X and not see the console that we have
   panic'ed. This is to distingush panics from "real" lockups.
   Could in theory send the panic message as morse, but that is left as an
   exercise for the reader.  */

“Andrew Rodland stumbled across this comment, and as he
explains, ‘not being the kind to step down from a challenge (unless
it’s just really hard), I decided to write morse code output code.’
His patch against Linux kernel version 2.4.19-rc1-ac1 (plus
preempt) actually modifies the kernel to report a panic in morse
code! Andrew also submitted a small sample module for generating
test panics.

Complete
Story

Get the Free Newsletter!

Subscribe to Developer Insider for top news, trends, & analysis