Messages in this thread |  | | Date | Fri, 8 Dec 2000 12:44:05 +0100 (MET) | From | "Maciej W. Rozycki" <> | Subject | Re: Why is double_fault serviced by a trap gate? |
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On Thu, 7 Dec 2000, Richard B. Johnson wrote:
> I am not denying the possibility of "warm-booting", i.e., > reloate some code to where there is a 1:1 physical to virtual > translation, jump to the relocated code, disable paging, restart kernel > code, and possibly examine what happened. You just have to get > back to "flat-mode" with no paging to handle anything beyond a > double fault. You are just not going to be able to restart > from the stack-faulted code.
If you want to handle triple faults (well, there should be none of these given a proper double fault handler) you may use the NMI as well. You are guaranteed to receive a NMI after a while when the watchdog is active (it is for SMP systems by default now and it will be for P6+ UP systems for Linux 2.5 as well). At least current Intel chipsets do not assert RESET to the CPU as a response to the shutdown special cycle in their default configuration (we may even explicitly force that behaviour).
-- + Maciej W. Rozycki, Technical University of Gdansk, Poland + +--------------------------------------------------------------+ + e-mail: macro@ds2.pg.gda.pl, PGP key available +
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