Re: PROBLEM: Panic booting from USB disk in ioremap.c (line 81)

[Len Brown <len.brown@intel.com>]

bootflag.c should not use its own private ACPI table parser/mapper --
this is a bug:

http://bugme.osdl.org/show_bug.cgi?id=1922

Elliot,
If you add your system info to that bug report and volunteer to help
test the fix, I'll be delighted to use your system as an excuse to
address this issue promptly.

thanks,
-Len

ps.
The reason you enter diag mode when SBF is disabled is because w/o SBF,
the BOOTING flag doesn't get cleared, so the BIOS assumes the system
didn't boot correctly and when entered next it is in DIAG mode.  This is
expected.

IMO, module load time is probably too early to clear the BOOTING flag
anyway.  It should be cleared upon completion of successful boot --
though I'm not sure how to identify that point.  Come to think about it,
maybe we should delay clearing the BOOTING flag until Linux initiates a
graceful shutdown, sleep, or reboot?  If the system died b/c of bad RAM
or something, that would make it run through DIAGS when it next enters
POST.