Subject: [x86] single-stepping in DDB eventually causes machine to reboot?
To: None <port-i386@netbsd.org>
From: Rafal Boni <rafal.boni@metatel.com>
List: port-i386
Date: 05/17/2000 13:12:28
Folks:
	I was trying to track down why pnpbios causes my machine to reboot
	without falling into DDB, and was therefore single-stepping through
	a bunch of code in pnpbios.

	After some amount of single-stepping, my machine would spontaneously
	reboot.  I'm 100% certain that it had nothing to do with the current
	instruction I was stepping through, as it happened in random points,
	often with quite harmless instructions (jnz to somewhere in the same
	function, add constant to register, ...).

	Is this expected behaviour?  If so, can someone quickly explain why?
	This is stepping through pretty early stages of kernel autoconfig, so
	there may be some bad interaction there, but I'd expect DDB to "just
	work".
	
	[I'm CC'ing tech-kern just in case...]

Thanks for any clues!
--rafal

----
Rafal Boni                                              rafal.boni@metatel.com
  PGP key C7D3024C, print EA49 160D F5E4 C46A 9E91  524E 11E0 7133 C7D3 024C