> I've a stranged issue with openbsd 3.9.
> 
> I've hacked the installer script to install openbsd automatically. Everything 
> works fine excepted dmesg output.
> 
> In a normal installation from CD, after N reboot, when I do a "dmesg", I've 
> got only the LAST dmesg (the current boot). But with my installer, I've got 
> all the dmesg following. To correct, I've a solution:
> 
> I replace the
>       dmesg > /var/run/dmesg.boot
> in /etc/rc by
>       dmesg | sed -ne '/^OpenBSD /h;/^OpenBSD /!H;${g;p;}' 
> >/var/run/dmesg.boot
> 
> But it doesn't explain WHY i've got this stranged issue.
> 
> In my installer, I've replaced every user input by a static value (for 
> tested) 
> and I did'nt touch something else.

If the kernel finds that the dmesg buffer in the kernel address space
is still intact after a reboot, it does not clear it.  It continues to
append strings to it.

Some machines clear the dmesg buffer during their bootup process, as a
result of destructive memory testing.  Others do not, and hence, you
will get the old and new dmesg's smashed together.

We specifically do things this way so that any crash-related data will
be retained.

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