🚀 go-pugleaf

In article <axifwk.cwc@wang.com> bnh@wiis.wang.com writes:
>
>   What is the difference between the GNU KDB (kernel debugger) and 
>various other KDB's, e.g. ATT's, SCO's? Does the GNU KDB allow one
>to debug device drivers and a Unix kernel? The application side of the
>SCO KDB is very small, essentially a system call to the kernel side of
>KDB. GNU KDB seems to run totally as an application. So I am confused?
>Please feel free to email a response or post one. Thanks in advance for 
>any help.

There are at least two flavors of gdb-based cross-debuggers.  One of
them was done at Tektronix for debugging kernels and standalone
diagnostic code on XD-88 workstations.  This gdb runs on a host and
communicates with the target machine over a serial line.  The target
has a small program in ROM or in out-of-the-way RAM that works
hand-in-hand with gdb on the host to start and stop the program being
debugged, probe memory, etc., in response to user commands.  This small
program is called the target debug monitor and Tektronix makes it
available for free under conditions similar to those in the GPL.

This cross-debugger was used heavily by Tektronix to debug all parts of
the kernel code.  Certainly a lot of disk, serial, and ethernet code
was debugged with this.  Diagnostic software engineers also used this
debugger to download boot ROM images to debug changes before burning
new EPROMs.  The cross-debugging support was originally tacked onto dbx
and only moved to gdb in the last year.  It had several years of about
10-20 engineers using it daily before being moved to gdb.

It is now in use by engineers at Horizon Research, Inc. to debug a Mach
kernel running on a 4-CPU MVME188 system.  They use a SUN/4 as the
host.

This has also been ported to the 68010 and in use here in the Real-Time
System group at the University of Washington (though this port is still
buggy, barely usable).

There is another flavor of gdb cross-debugger, one that I believe was
done by GNU itself and I think that this is what people usually mean
when they refer to the "gdb cross-debugger."  I wanted to make it clear
that there are at least two different gdb-based cross-debuggers.

	Rob