Unable to boot Asus P5QL-EM w/ acpi enabled

John Baldwin jhb at freebsd.org
Thu Sep 25 13:29:56 UTC 2008


On Thursday 25 September 2008 03:11:18 am Navdeep Parhar wrote:
> On Thu, Sep 25, 2008 at 12:42:38PM +0800, Jia-Shiun Li wrote:
> > On Thu, Sep 25, 2008 at 1:35 AM, John Baldwin <jhb at freebsd.org> wrote:
> > > On Wednesday 24 September 2008 01:11:31 pm jiashiun li wrote:
> > >>
> > >> I did a binary search and found the problem lies between 2008-08-22
> > >> and 2008-08-23. Here is my note:
> > >>
> > > If you grab the latest bits from HEAD you can use 'hw.pci.mcfg=0' to 
disable
> > > memcfg.
> > >
> > 
> > Thanks, quick search the mailing list revealed some cases and your
> > solution just a few days ago. I should have followed the mailing list
> > more carefully. ;)
> > 
> > Just curious, any idea why the memory mapped configuration prevents
> > kernel from booting? Maybe buggy hardware, acpi code, or combination
> > of both that users can help testing to find the cause?
> 
> I would like to put in a me-too here.  I've been using hw.pci.mcfg=0
> since it was introduced but I still don't know where exactly the problem
> is, or how to pinpoint it (bad bios/bad hardware/bad phase of the
> moon/etc).  The bleeding versions of other OS'es seem to work out of the
> box, though that doesn't mean much - I'm not sure what they do inside.

I'm not sure.  Probably other OS's aren't using this a lot yet so it is just 
buggy BIOS.  Linux has a rather silly SMAP-related check (requires an 
explicit SMAP region that covers the memcfg area) that effectively disables 
memcfg on most boxes, so Linux probably isn't using it on your hardware 
either.

-- 
John Baldwin


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