Re: How to get into ddb after system is booted?

[Eduardo Horvath <eeh%NetBSD.org@localhost>]

On Tue, 31 Jan 2012, Paul Goyette wrote:

> On Tue, 31 Jan 2012, Eduardo Horvath wrote:

> > wskbd.c currently does not support cnmagic.  Someone should probably add
> > that.  OTOH, someone should also change wscons so we don't translate from
> > USB keycodes to whatever we're using internally to what the X server
> > expects.  It's redundant and really complicates things like adding cnmagic
> > support.
> 
> :)
> 
> I infer from your comment that I'm not likely to be succesful with ddb.

Well... CTRL-ALT-ESC should work from a USB keyboard to get to ddb... 
unless you're running X.  However since the com driver does have cnmagic 
support, if that were the console you should be able to use that to get to 
ddb.  But if it were the console then you probably would have issues with 
frame buffer initialization and X might not work.  Sigh.  I really wish 
wscons worked nicely with other console devices.

> Since I really only need to update a single memory location (to enable some
> additional printf's), can this be done with gdb on the running machine?  Can I
> make gdb write to /dev/mem or /dev/kmem ?

If that's all you want to do you should be able to use gdb with /dev/mem.  
I used to do that with adb on solaris all the time and don't see why gdb 
wouldn't work.

Eduardo