Date: Sun, 16 Feb 1997 23:51:36 +0000 (GMT)
From: alberto DOT vignani AT torino DOT alpcom DOT it (Alberto Vignani)
Subject: For DOSEMU users - djgpp and ^C troubles
Apparently-to: djgpp AT delorie DOT com
To: djgpp AT delorie DOT com
Message-id: <199702162351.XAA16071@monviso.alpcom.it>
Content-transfer-encoding: 7BIT

Hi.

Take a program compiled with djgpp 2.0, even a very simple one. Run it under
Linux dosemu (0.64 or 0.65 version). Stop it with ^C and restart it.
If you are not satisfied with the results :(, you can try this patch:

----------------------------------------------------------------------------
diff -urN dosemu-0.65.0.6/src/dosext/dpmi/dpmi.c dosemu-0.65.0.6/src/dosext/dpmi/dpmi.c
--- dosemu-0.65.0.6/src/dosext/dpmi/dpmi.c	Fri Jan 24 09:47:46 1997
+++ dosemu-0.65.0.6/src/dosext/dpmi/dpmi.c	Sun Feb 16 23:59:47 1997
@@ -2986,7 +2986,13 @@
 	}			/* _trapno==13 */
 	else
 #ifdef __linux__
-		do_cpu_exception(scp);
+	/*
+	 * When we stop a djgpp program with ^C, it just goes down, and
+	 * we get a stack exception. If we continue we stay in DPMI,
+	 * and this is _not_ a good thing. dosemu or djgpp library bug?
+	 */
+		if (_trapno == 12) quit_dpmi(scp,1); else
+			do_cpu_exception(scp);
 #endif
 #ifdef __NetBSD__
 	do_cpu_exception(scp, code);
----------------------------------------------------------------------------

Can someone (Eli?) enlighten me on what's going on when you press ^C?
When a djgpp program terminates normally, I see all the shutdown sequence
up to the int0x21-AX=4Cxx which signals dosemu to quit the DPMI server.
This doesn't happen with ^C; on the dosemu side, I have currently to rely
on the stack fault to understand what went on. There should be a better
way.

Thanks
Alberto