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From: Lowell Gilbert <freebsd-questions-local@be-well.ilk.org>
To: Andrea Venturoli <ml@netfence.it>
Cc: questions@freebsd.org
Subject: Re: Spontaneous reboots with splash
References: <5627D8B8.7030901@netfence.it> <5628CD2B.2000902@gmail.com>
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Date: Thu, 22 Oct 2015 23:22:52 -0400
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Andrea Venturoli <ml@netfence.it> writes:

> On 10/22/15 14:18, Mehmet Erol Sanliturk wrote:
>
>> If you have two identical computers with the same programs running :
>> One is working correctly , but other one is booting arbitrarily :
>
> I've got another identical box; I'll restore a dump on this and see if
> the behaviour is the same.

That will establish if the issues are hardware, certainly.

>> Therefore , there is a necessity to check that
>> - processor is working correctly
> CPU Burn-in says yes.
>
>> - memories are working correctly
> Memtest 86+ says so.

Those are checking the main system, not the graphics subsystem. If this
is a hardware problem, it's far more likely to be in the graphics memory
or the graphics processor.

>> Another possibility is that a program is broken ( contains an invalid address )
>> in HDD . When it starts to working  , it jumps to that broken
>> address and this may start the boot .
>
> Would a userland program be allowed to do this???

No, but splash(4) is part of the kernel, so it would be allowed to do that.