BTX loader hangs after version info

[Peter Holm]

On Mon, May 26, 2008 at 02:23:11PM +1200, Mark Kirkwood wrote:
> Peter Holm wrote:
> >On Sun, May 25, 2008 at 08:33:01PM +1200, Mark Kirkwood wrote:
> >  
> >>I wrote:
> >>    
> >>>John Baldwin wrote:
> >>>      
> >>>>Try this patch.  I'm not 100% certain this will fix it as I can't 
> >>>>reproduce
> >>>>the issue, but I think it might help.  Specifically, when the boot 
> >>>>code makes
> >>>>a v86 call, the loader/boot2/whatever swaps in/out a new set of 
> >>>>registers via
> >>>>the v86 structure including the eflags register.  However, none of 
> >>>>the boot
> >>>>programs actually initialized the v86 structure.   Thus, the BIOS 
> >>>>routines
> >>>>would start off running with whatever garbage was in v86.efl when 
> >>>>each boot
> >>>>program started.  This meant that we could end up invoking BIOS 
> >>>>routines with
> >>>>interrupts disabled, and I think this might explain a hard hang (if a 
> >>>>BIOS
> >>>>routine was waiting for an interrupt the interrupt would never 
> >>>>fire).  The
> >>>>patch fixes all the boot programs to initialize v86 to a better known 
> >>>>state. At the least it sets v86.efl to a sane value (0x202) rather 
> >>>>than random.  (The
> >>>>random might have always been 0x0 BTW, not sure on that one.)
> >>>>
> >>>> 
> >>>>        
> >>>Thanks John,
> >>>
> >>>Unfortunately this patch does *not* cure the issue for my old 
> >>>Supermicro P3TDDE, it still hangs just before presenting the menu. I 
> >>>had to boot off the livefs and copy /boot/loader.old -> /boot/loader 
> >>>to get back to being bootable again - but at least the old fella is on 
> >>>a more up-to-date 7-STABLE now :-)
> >>>      
> >>Given that the patch *did* cure Peters Tyan S2720, I'll double check I 
> >>didn't fat finger applying the patch (mind you the Tyan has AMI BOIS - 
> >>same as my Supermicro P3TDERs that *do* work ok with current 7-STABLE, 
> >>whereas the P3TDDE has Award BIOS).
> >>
> >>Anyway, I'll double check and report back...
> >>
> >>Cheers
> >>
> >>Mark
> >>    
> >
> >I did 18 boots with and with out John's patch. With the patch I got 6
> >actual boots and 12 hangs in the loaders progress bar.
> >
> >Without the patch I got 10 boots and 8 hangs.
> >
> >But, my Tyan M/B is old and with known ACPI issues so I'm not sure if
> >this is of much value.
> >
> >Mark, it would be nice if you also observe if a sequence of reboots
> >eventually boots your system. My longest bad streek was 8 reboots.
> >
> >  
> 
> Yeah, I see the same thing - with John's patch applied, out of 9 reboots 
> I got 7 hangs and 2 actual boots.  (didn't try without the patch).
> 
> Mark

OK, that is at least nice with consistency across different HW.

-- 
Peter