# Mysterious 'Fatal Trap 12'...



## Blackbird (Jul 7, 2010)

Hi, when I booted up today I got the following message:


```
Fatal Trap 12: page fault while in kernel mode
cpuid = 3; apic id = 03
fault virtual address  = 0x8fca3a04
fault code             = supervisor read, page not present
instruction pointer    = 0x20:0xc07f010a
stack pointer          = 0x28:0xc677fb74
frame pointer          = 0x28:0xc677fba8
code segment           = base 0x0, limit 0xfffff, type 0x1b
                       = DPL 0, pres 1, def32 1, gran 1
processor eflags       = interrupt enabled, resume, IOPL = 0
current process        = 2 (g_event)
trap number            = 12
panic: page fault
cpid = 3
Uptime: 6s
Cannot dump. Device not defined or unavialable.
Automatic reboot in 15 seconds - press a key on the console to abort
```
About 3 Seconds later my keyboards stopped working...
I had made a adjusted generic kernel with only i686 and without floppy or ipv6.
It worked well the last few days.
The last thing I did was installing KDE...:\

When I booted with ACPI disabled, I got the same message but with CPU 1 instead of 3, and with different pointer and adress codes.
When I booted in safe mode, it was CPU 0.
Single user mode worked.

And after exiting single user, everything worked fine! WTF?!

Well, I am new to FreeBSD but want to really _understand_ my system...
Could you pleeaase explain to me what and why that was? Or at least, what it could have been?

Thank you.


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## zeiz (Jul 7, 2010)

Looks like hardware problem. Or just voltage problem. May be "too tough" settings in BIOS. May be memory dimms were inserted not quite properly.
It's less likely that FreeBSD has improper support for your mobo chips though once I got it during 8.0 betas. 
What did you do during single user mode?


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## Blackbird (Jul 8, 2010)

Well I didn't change anything in BIOS the last three months...
And in SU modus I didn't do anything as well, just one 'ls' and 'exit'.


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## zeiz (Jul 8, 2010)

You may want to run memory test, reinstall memory modules, check for dust, fans etc.

Besides hardware... you've built custom kernel, maybe something went wrong during the building.
Check your kernel config file (or recreate it), update src and build kernel again.

Also you may search this forum for similar errors. For example I briefly tried and found
http://forums.freebsd.org/showthread.php?t=7791 =>
http://www.freebsd.org/cgi/query-pr.cgi?pr=140979


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