Date: Thu, 22 Oct 2015 09:18:54 -0700 From: Mehmet Erol Sanliturk <m.e.sanliturk@gmail.com> To: Andrea Venturoli <ml@netfence.it> Cc: Ernie Luzar <luzar722@gmail.com>, "questions@freebsd.org" <questions@freebsd.org> Subject: Re: Spontaneous reboots with splash Message-ID: <CAOgwaMvG0VoafNjme_c6dEhQ%2BZsKAO0_Q0i97=ta9=TPF=ZhBw@mail.gmail.com> In-Reply-To: <5628FD40.1030701@netfence.it> References: <5627D8B8.7030901@netfence.it> <5628CD2B.2000902@gmail.com> <5628CFA7.6040704@netfence.it> <CAOgwaMvH5RbAghKCrhWQ7B=8TUVBxoeAXtrQHGK8qWkwCyXUsg@mail.gmail.com> <5628FD40.1030701@netfence.it>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, Oct 22, 2015 at 8:14 AM, Andrea Venturoli <ml@netfence.it> wrote: > 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. > > > > > 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. > > > > - memory management chips are working correctly . >> > > I have no idea how to check. How do I do this? > > > If memory tests are showing memories are working correctly , it is possible to say that memory management chips are also working correctly . Otherwise , it is not possible to write into and read from chips correctly . If memory chips fail , by testing with correctly working chips known , the problem may be attributed to memory management chips . Another possibility is the Watt level of Power Supply : If the required watts is exceeding the existent power supply watts level , it may cause reboots when power use increases beyond its capacity . Another possibility is power supply is cutting power spontaneously or causing fluctuations . > > Another problem may be a program which is causing generation of an >> invalid address showing boot start code and jumping into it . This is >> very easy for a i386 real mode program . >> > > In that case this program would be FreeBSD! That's why I'm asking here. > > > > If you can isolate the program causing boots , it will be possible to check its sources and binary file . > > 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??? > > > Let's assume that CPU is not over-heated and is not rebooting the computer like motherboard is powered . Let's assume that there is no any malicious program part to cause rebooting . A broken network card may corrupt data and may cause serious problems . The remaining possibility is that instruction counter value is destroyed in a program and showing the BIOS boot code area . To reboot the computer , it is necessary to start BIOS boot code This may occur also during BIOS related calls . Instead of a proper interrupt code , boot part is invoked . Otherwise we will say that within FreeBSD OS parts , there is a point that , instead of a proper shut down , it is directly rebooting the computer by calling BIOS boot code . Checking panic points and searching OS sources for such a reboot code ( without any error message and request approval from the user ) existence may help . Here the most important part is to find the program part which is causing the reboots . Studying this program part will reveal the reason and , therefore the cure . I can not say any correct sentence here about FreeBSD internals due to ( not sufficient knowledge ) . Since that computer is not working properly , you can do the following : Reinstall OS into a spare disk and check with it . This will identify whether problem is caused by the presently installed OS or not . If it can execute 64-bits OS , testing with such an OS will identify effect of OS or hardware . > > bye & Thanks > av. > Mehmet Erol Sanliturk
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAOgwaMvG0VoafNjme_c6dEhQ%2BZsKAO0_Q0i97=ta9=TPF=ZhBw>