Revert r341337; according to imp@ we still support these.

MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
This commit is contained in:
Edward Tomasz Napierala 2018-11-30 15:52:03 +00:00
parent fd2f7a7f90
commit 7f92f23316

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@ -1491,8 +1491,17 @@ might be defined to have special handling, and
might be defined to simply panic and reboot. might be defined to simply panic and reboot.
.El .El
.Sh HINTS .Sh HINTS
On machines with an ISA expansion bus, a simple NMI generation card can be
constructed by connecting a push button between the A01 and B01 (CHCHK# and
GND) card fingers.
Momentarily shorting these two fingers together may cause the bridge chipset to
generate an NMI, which causes the kernel to pass control to
.Nm .
Some bridge chipsets do not generate a NMI on CHCHK#, so your mileage may vary.
The NMI allows one to break into the debugger on a wedged machine to The NMI allows one to break into the debugger on a wedged machine to
diagnose problems. diagnose problems.
Other bus' bridge chipsets may be able to generate NMI using bus specific
methods.
There are many PCI and PCIe add-in cards which can generate NMI for There are many PCI and PCIe add-in cards which can generate NMI for
debugging. debugging.
Modern server systems typically use IPMI to generate signals to enter the Modern server systems typically use IPMI to generate signals to enter the