Re: [GSoC] Remote kernel debugging over Ethernet

[Allen Briggs <briggs%netbsd.org@localhost>]

On Thu, Mar 26, 2009 at 02:13:54PM +0200, Jordan Gordeev wrote:
> I found ipkdb a few days ago. I found out that it is dead too.
> Do you think it should be revived and new drivers written for it?

I think the first thing to do is determine that.  As I recall, ipkdb was
using a now-obsolete protocol, but my recollection could well be wrong.

> >>One important question to ask is what the *goal* of kernel debugging  
> >>over Ethernet is. There are virtualization solutions that can be used to  
> >>debug a kernel without hangs and crashes.

gdb is much nicer than ddb for some debugging tasks.
gdb on a live kernel needs some kind of remote access.
Some systems have no serial ports.
Some systems have one serial port, but use it for the console.

ieee1394 is nice for a few reasons mentioned in this thread, but it's
not available on all systems.  Ethernet is available on most systems--
certainly more systems than ieee1394.

The biggest hurdle for GDB over ethernet is dealing with the large
number of ethernet drivers.  We currently don't have a generic way
of running network traffic without interrupts being enabled, but
you don't really want interrupts enabled while debugging.

-allen

-- 
Allen Briggs  |  http://www.ninthwonder.com/~briggs/  |  
briggs%ninthwonder.com@localhost