Date: Sun, 19 Mar 95 00:55:28 EST
From: peprbv AT cfa0 DOT harvard DOT edu (Bob Babcock)
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: Debugging a Graphics application
Reply-To: babcock AT cfa DOT harvard DOT edu

> I tried it, but no success. It wrote that I should use ed32-dpm
> version in DPMI environment, but I didn't find any in ldbg100.zip.

The dpmi version was omitted because it doesn't work yet.  The problem has to
do with setting up the environment properly, but a simple work-around is to
replace the call to stat() in sys_init() in syms.c with an access call.
Here's the old and new lines pasted from my copy of the source:
   /*    if (stat(symfilename,&statbuf) != -1) */
       if(0 == access(symfilename, 4))
My understanding is that the stat call crashes because it eventually leads to
a call to getenv().  Even with this change, I don't think the serial port
debugging will work under dpmi; at least, it didn't work for me under OS/2.
I'm working on mods to allow debugging over a pipe in OS/2.  I got it working
well enough to verify that the concept was feasible, but I haven't had time
to straighten out what should get written to the local screen and what to the
debugger screen.  There are several more urgent things on my queue so I don't
know when I'll have time to get back to this.