panic: free: guard1 fail @ 0x6c23c

Erik Trulsson ertr1013 at
Thu Feb 28 15:36:01 UTC 2008

On Thu, Feb 28, 2008 at 03:16:35PM +0000, Pedro Almeida wrote:
> I upgraded my system from 6.2 to 7.0 using cvsup.
> I'm using ULE and device polling. After doing make installworld and reboot, 
> the system
> don't boot anymore. I have some variables in make.conf, but I don't know if 
> this the cause of the problem.
> CFLAGS= -O2 -pipe -funroll-loops -ffast-math
> COPTFLAGS= -O2 -pipe -funroll-loops -ffast-math
> Any ideas of how to fix this? Thanks a lot

I don't know if the make.conf variables you show are the cause, but it would
not surprise me.  I would suggest you remove CFLAGS and COPTFLAGS entirely from
make.conf and just relying on the default values for them (which are
'-O2 -pipe -fno-strict-aliasing'.
The flags you use are unlikely to bring any noticable improvements compared
to the default, but are likely to make code misbehave.

> Can't work out which disk we are booting from.
> Guessed BIOS device 0xffffffff not found by probes, defaulting to disk0:
> panic: free: guard1 fail @ 0x6c23c
> from /usr/src/sys/boot/i386/loader/../../common/module.c:959
> press any key to reboot

<Insert your favourite quote here.>
Erik Trulsson
ertr1013 at

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