Re: kern/46885: NetBSD 6.0_RC1 spontaneously reboots as kernel starts to load

[David Laight <david%l8s.co.uk@localhost>]

On Sun, Sep 02, 2012 at 09:15:07PM +0000, Valeriy E. Ushakov wrote:
>  
>  I did a few more experiments under vbox --recompile-supervisor
>  (i.e. ~= qemu interpreter) and it looks sensitive to size.
>  
>  Playing with the following config:
>  
>  
>    include     "arch/i386/conf/GENERIC"
>    options     PCIVERBOSE
>  
>    # this line has 64 bytes ######################################
>    ###############################################################
>    ###############################################################
>    ...
>  
>  I do get bootable kernel without those comment lines added to beef up
>  the kernel size.  With 12KB worth of comments I get unbootable kernel.
>  With 16KB it's bootable again.  Current current will probably have
>  different numbers, but you get the idea.

Maybe nothing is flushing the dcache (or invalidating the icache)
before the kernel starts?
That would lead to obscure size based fubars.

With vbox/qemu it might be possible to work out which!

Another issue I have seen (a long time ago) was memory overwrites
caused by rx ethernet frames when an ethernet chip didn't get reset.

        David

-- 
David Laight: david%l8s.co.uk@localhost