From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2480 invoked by alias); 10 Sep 2003 16:48:45 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 2470 invoked from network); 10 Sep 2003 16:48:44 -0000 Received: from unknown (HELO gateway.macdonnell.ca) (68.145.162.148) by sources.redhat.com with SMTP; 10 Sep 2003 16:48:44 -0000 Received: from macdonnell.ca (desktop.localdomain [192.168.0.4]) by gateway.macdonnell.ca (8.12.9/8.12.9) with ESMTP id h8AGme4B001637; Wed, 10 Sep 2003 10:48:41 -0600 Message-ID: <3F5F55F1.9020905@macdonnell.ca> Date: Wed, 10 Sep 2003 16:48:00 -0000 From: Creighton MacDonnell User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 To: gdb@sources.redhat.com CC: Thomas Doerfler Subject: Re: Problem with COM1 port from with GDB 5.3 under Cygwin 1.5.3-1 References: <3F5F2C94.31945.291668BC@localhost> <3F5F5C7D.5659.2D0964@localhost> In-Reply-To: <3F5F5C7D.5659.2D0964@localhost> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2003-09/txt/msg00138.txt.bz2 As I mentioned in my first posting, the code in GDB for accessing serial ports seems quite complicated. It does not just attempt to open whatever you specifiy for a device name. There is code that builds up some sort of "list of devices". I expect this is to assist portability. But iin this case I think it is doing the opposite. When I tried to use "/dev/ttyS0" as a device name under the old Cygwin, GDB would say it "could not open the device". But I think what may actually be happening is that "/dev/ttyS0" did not make it into the list of devices. I fear that GDB may be attempting to get a list of interfaces, or information about interfaces, using some sort of lower level system calls which Cygwin just stubs out. This might not only cause GDB to not realize the device name is actually OK, but may cause it to attempt to open COM? with inapproriate options. If I were a Cygwin maintainer, and knew that GDB did not allow names such as "/dev/ttyS0" under the old Cygwin, I might react that GDB should be made "Cygwin-compatible" first. And after that, if there are still problems with the "com?" names, they may want debug information that could only be obtained by putting debug code into GDB. In the end, it is we GDB under Cygwin users that have the problem. It does not appear that many other Cygwin users care much about the serial port. Thomas Doerfler wrote: >Hello, > >I just have passed some similar tests. I have connected a >Win32 terminal program to one COM port, and was trying to send >data to the other port using cygwin, with a loopback (null- >modem) cable attached. > >I could > >$ echo bla >/dev/ttyS1 > >and even > >$ echo bla >COM2 > > >and got the result on the serial line (and into my terminal >screen) > >So at least sendig data from cygwin works fine. > >Currently I don't know how to come around this. The problem >seems to be more connected to cygwin, because we see this with >at least two different gdb versions... > >wkr, > Thomas. >