Subject: Re: 24ibt on ZX/leo framebuffer, cg8/12, and doing kernel src debugging with kernel kgdb stub and ddd+gdb
To: None <johns@umr.edu>
From: Piet Delaney <piet@cup.hp.com>
List: tech-kern
Date: 02/25/1999 18:37:25
Hi John:

   This afternoon I received mail from Todd Fries and he suggested touching 
bases with you on working on the leo driver(s).

  I've got a Leo and an sbus based cg8/cg12, I'll have to check which, anyway both 
are 24 bit true color cards and I wrote a 24 bit true color driver a while back and
was wondering about helping out on one. I've got NetBSD, OpenBSD, and Linix
running at home on some old SPARCstations and I'm about to install FreeBSD on
an Ultra SCSI dual processor Pentium. I'd like to work on the kernel with kgdb 
but I've been having trouble getting the kgdb stub code linked on the OpenBSD kernel. 
I used something like kgdb here at HP and have used it on SunOS and Solaris (kdbx). 
Seems ddd on top should be no sweat. I find it hard to believe that the OpenBSD
kernel hackers aren't using kgdb on OpenBSD. Worlds a bit strange. I have to admit I
 didn't try very hard  yet; just a few hours. We really should be running the 
stub over it's own ethernet code and minimal hooks into the ethernet drivers. Then 
you can remote debug a lot of kernel bugs on system anywhere in the world; it's 
real slick. I was a bit impressed that microsoft releases NT with a version compiled
-g on the CD for remote src level debugging. I wonder why the major UNIX corporation
aren't also doing this. Seem like some lawyers told them the debugger information 
could be reverse engineered back into code; I really doubt that.

	If you have any suggestion on the true color frame buffer drivers on
setting up kgdb on openbsd, I'd appreciate hearing about it. I know it works on
Linux but I'm not sure abot FreeBSD. Likley still works on NetBSD but the code
has changes a lot since my old NetBSD got installed. OpenBSD is running pretty
good these days, I used ddd and gdb on a core file but the problem wasn't obvious
other than I unpluged the scsi connector; seems it shouldn't panic. I set up kgdb
on sunos over a few weekends so I doubt it will take very long. The frame buffer
driver I did last took about 3 months but all I had was adb. With kgdb I'd expect
we could get it working in a few weeks.


-piet