kernel debugger and usb keyboard
alexbestms at math.uni-muenster.de
Mon Aug 3 22:37:25 UTC 2009
thanks a bunch for the info. although usb keyboard support isn't as mature as
at keyboard support in the kernel debugger it's good to have some basic
Hans Petter Selasky schrieb am 2009-08-03:
> On Monday 03 August 2009 20:55:16 Alexander Best wrote:
> > just tried settings `sysctl debug.kdb.panic = 1`. if i use this way
> > to
> > enter the kernel debugger my usb keyboard works. if i type
> > "continue"
> > however the kernel panics and the kernel debugger gets yet entered
> > again,
> > but without the keyboard working.
> The USB controller which the keyboard is hooked onto will not work
> after panic
> has been entered, due to some state not being cleaned up.
> To increase the chance of the keyboard working on a panic, connect
> keyboard to a separate USB controller.
> > i don't know how to produce backtraces since the keyboard doesn't
> > work.
> > the other way of entering the debugger without my keyboard working
> > was to
> > simple press "ctrl+ast+esc".
> Yes, because most likely the DDB is entered directly from the USB
> code, and the USB stack does not allow function recursion in that
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