Re: Anyone else seen this.

In comp.os.linux.misc The Natural Philosopher <[email protected]> wrote:
> Recently my router (Draytek 2726) has been spontaneously rebooting.
> 
> Examination of the logs show a kernel panic caused by 'attempt to 
> execute an illegal instruction'.
> 
> My assumption, possibly erroneous, is that the actual firmware code is 
> corrupted

Do you have logs for multiple reboots?  If yes, do they show the 
"illegal instruction" panic at the same address/instruction?

Corrupted firmware should show the same panic each time the issue 
occurs (because the false change to the stored firmware would remain at 
the same firmware address).

> The router is rated only to +45°C but that is the recommended limit for 
> flash memory, and the room temperature has been up towards 40°C. which 
> doesn't leave a great deal of margin for router internal heat production.
> My query is whether anyone else has seen issues with flash memory in the 
> recent hear wave.

If the logs show illegal instructions at differing addresses that 
points towards some borderline component (which may still be the flash) 
that exceeds the systems ability to compensate when the temp is this 
high.  Other possibilities could be the CPU itself may, above a certian 
temp, simply become flakey.  Depending upon what specific CPU the CPU 
may be the warmest, or second warmest, component in the entire system 
and with a 40C room temperature it may be operating at a point where it 
randomly glitches.  It could also be something as mundane as a power 
supply capicator that has partly dried out, and at the higher ambient 
operating temperature it is allowing more ripple to pass through to the 
DC rails, resulting in occasional random corruption of data somewhere 
due to that ripple.

> Surely phones get hotter than this?

It is possible that phones may use higher temp rated components.