Messages in this thread | | | From | Systemkennung Linux <> | Subject | Re: [PATCH-2] NMI trap revised (was Re: NMI errors in 2.0.30??) (fwd) | Date | Thu, 15 May 1997 04:46:47 +0200 (MET DST) |
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> > On Tue, 13 May 1997, Gabriel Paubert wrote: > > > During the NMI routine all interrupts are masked anyway, and even NMIs are > > masked until the CPU executes an IRET instruction. But the problem is > > printk... > > Not true with ix86 processors. To mask non-maskable interrupts you adjust > a bit in port 0x61 (I don't have the documentation here). This is the > "keyboard" chip which is really a port/uP with built-in ROM. This > physically disconnects the NMI line to the processor. I think it is > either bit 4 or 5. Anyway non-maskable interrupts are not maskable which > means CLI and STI don't affect them. Therefore the INT bit in the flags > register (which would be restored from the stack upon an IRET) does not > affect it.
Dick ist right. Hey, after all NMI stands for "Non Maskable Interrupt" ...
Ralf
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