On 22.09.2016 20:32, Jean-Roch Blais wrote:
> Hello Andrew, Erich !
>> Le 21 sept. 2016 à 04:52, Andrew <ni...@seti.kr.ua> a écrit :
>> Most of boards have some kind of watchdog on board (in MIO or in south
>> bridge), or some of them. For ex., iTCO_wdt for Intel, it87_wdt for ITE
>> MIO, and so on.
>> But built-in watchdog behavior may differ depending board model (it may
>> reboot board, or it may just poweroff board, like ITE watchdog on old
>> Asus K8N).
>> Also, Intel watchdog driver is loaded automatically, MIO watchdog
>> drivers are loaded manually (from command line or from /etc/modules).
>> You can try it - load driver, and then do 'killall -9 watchdog' (to kill
>> watchdog process & simulate system hangup). If board will be rebooted -
>> all is OK.
> Yes it does that indeed, I killed the watchdog0 and 1 plus the watchdog 
> processes and my system rebooted, the drivers are already loaded in BUC ( 
> lsmod gives iTCO_wdt ), no need to load anything, but it’s good to know how 
> it works. But my question still stands, there is no hardware lockup watchdog 
> timer, it has to be an external contraption which would detect an absence of 
> activity on the motherboard and activate the hardware reset button… I’ve seen 
> some wifi switches that do this for routers 
> (https://www.amazon.com/gp/product/B01BU2ALGO/ for exemple).  It does not 
> ship to Canada though :-) !!!  I’ve started some preliminary tests to perform 
> the same basic thing using an Arduino on one of BUC’s USB port, and it looks 
> promising… if you are interested I could let you know how it goes !
> bye !
You are wrong, iTCO_wdt is hardware watchdog timer. It doesn't use CPU 
for rebooting - this is separate circuit in the chipset.
You may even try to disable reboot on kernel panic and initiate kernel 
panic, or even teke out one DIMM module - and system will be rebooted.

leaf-user mailing list: leaf-user@lists.sourceforge.net
Support Request -- http://leaf-project.org/

Reply via email to