BTX loader hangs after version info

Mark Kirkwood markir at
Sun May 25 07:05:17 UTC 2008

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 :-)



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