Difference between revisions of "Magic SysRq Key"

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(New page: ==Introduction== Excerpt from Linux's Documentation/sysreq.txt:<br> ''What is the magic SysRq key?'' ''It is a 'magical' key combo you can hit which the kernel will respond to regardless ...)
 
(From any terminal on the APF)
 
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===From any terminal on the APF===
 
===From any terminal on the APF===
* Send the character to corresponding /proc interface. For example to reset the board:
+
* Send the character to corresponding ''/proc'' interface. For example to reset the board:
 
<pre class="apf">
 
<pre class="apf">
 
# echo b > /proc/sysrq-trigger
 
# echo b > /proc/sysrq-trigger
 
</pre>
 
</pre>
 +
 +
===From the LCD pseudo terminal with an USB keyboard===
 +
* To Be Tested...

Latest revision as of 14:42, 8 December 2011

Introduction

Excerpt from Linux's Documentation/sysreq.txt:
What is the magic SysRq key?

It is a 'magical' key combo you can hit which the kernel will respond to regardless of whatever else it is doing, unless it is completely locked up.

Usage

  • Check it is enabled:
# cat /proc/sys/kernel/sysrq 
1

From Host serial console with Kermit

  • Send break character (Ctrl-\ b) then the key corresponding to the wanted action. For example to reset the board you will press:
Ctrl+AltGr+8 then b then b

From any terminal on the APF

  • Send the character to corresponding /proc interface. For example to reset the board:
# echo b > /proc/sysrq-trigger

From the LCD pseudo terminal with an USB keyboard

  • To Be Tested...