Debian Bug report logs - #492741
screen is unable to set parity or stop bits when attached to a serial console

Package: screen; Maintainer for screen is Axel Beckert <abe@debian.org>; Source for screen is src:screen.

Reported by: Marc Haber <mh+debian-bugs@zugschlus.de>

Date: Sat, 21 Jun 2008 17:42:02 UTC

Severity: minor

Reply or subscribe to this bug.

Toggle useless messages

View this report as an mbox folder, status mbox, maintainer mbox


Report forwarded to debian-bugs-dist@lists.debian.org, Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>:
Bug#487418; Package cereal. Full text and rfc822 format available.

Acknowledgement sent to Marc Haber <mh+debian-bugs@zugschlus.de>:
New Bug report received and forwarded. Copy sent to Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>. Full text and rfc822 format available.

Message #5 received at submit@bugs.debian.org (full text, mbox):

From: Marc Haber <mh+debian-bugs@zugschlus.de>
To: Debian Bug Tracking System <submit@bugs.debian.org>
Subject: cereal: how to set parity, bit number, stop bits
Date: Sat, 21 Jun 2008 19:33:25 +0200
Package: cereal
Version: 0.22-1
Severity: minor

To be a fully featured serial console application, one needs the
possibility to set serial port parameters other than the baud rate. I
have not seen any serial port needing something other than 8 bits, no
parity, 1 stop bit in a long time, but that feature might be needed in
the future.

Greetings
Marc

-- System Information:
Debian Release: lenny/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (i686)

Kernel: Linux 2.6.25.7-scyw00225 (PREEMPT)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages cereal depends on:
ii  adduser                       3.108      add and remove users and groups
ii  procmail                      3.22-16    Versatile e-mail processor
ii  runit                         1.9.0-1    a UNIX init scheme with service su
ii  screen                        4.0.3-11   terminal multiplexor with VT100/AN

cereal recommends no packages.

-- no debconf information




Information forwarded to debian-bugs-dist@lists.debian.org:
Bug#487418; Package cereal. Full text and rfc822 format available.

Acknowledgement sent to Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>:
Extra info received and forwarded to list. Full text and rfc822 format available.

Message #10 received at 487418@bugs.debian.org (full text, mbox):

From: Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>
To: Marc Haber <mh+debian-bugs@zugschlus.de>
Cc: 487418@bugs.debian.org, cereal@fifthhorseman.net
Subject: Re: Bug#487418: cereal: how to set parity, bit number, stop bits
Date: Sun, 22 Jun 2008 10:49:17 -0400
[Message part 1 (text/plain, inline)]
Hi Marc--

On Sat 2008-06-21 13:33:25 -0400, Marc Haber wrote:

> To be a fully featured serial console application, one needs the
> possibility to set serial port parameters other than the baud
> rate. I have not seen any serial port needing something other than 8
> bits, no parity, 1 stop bit in a long time, but that feature might
> be needed in the future.

Thanks, this is a good suggestion.  Since cereal relies on screen, you
should be able set 7 bits instead of 8 bits by appending ,cs7 to the
baud rate.  e.g.

 cereal-admin create sevenbitcomms /dev/ttyS3 115200,cs7 foo foogroup

However, I haven't been able to test this properly because i don't
have any equipment that natively does 7bit serial connections.

I tried it against a grub instance configured with 

 serial --unit=0 --speed=115200 --word=7 --parity=no --stop=1

but was unable to get an active communication (though i don't know how
well-tested grub's --word=7 option is either).

If we can get this to work, it should probably be documented within
cereal-admin(8).

Unfortunately, searching through screen(1) i don't see how to set the
stop bits or parity of the connection.  Shall i clone this bug and
reassign the cloned bug to screen, referring to these features?

         --dkg
[Message part 2 (application/pgp-signature, inline)]

Information forwarded to debian-bugs-dist@lists.debian.org, Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>:
Bug#487418; Package cereal. Full text and rfc822 format available.

Acknowledgement sent to 487418@bugs.debian.org:
Extra info received and forwarded to list. Copy sent to Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>. Full text and rfc822 format available.

Message #15 received at 487418@bugs.debian.org (full text, mbox):

From: Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>
To: Marc Haber <mh+debian-bugs@zugschlus.de>, 487418@bugs.debian.org, cereal@fifthhorseman.net
Subject: Re: Bug#487418: cereal: how to set parity, bit number, stop bits
Date: Sun, 22 Jun 2008 11:05:09 -0400
[Message part 1 (text/plain, inline)]
On Sun 2008-06-22 10:49:17 -0400, Daniel Kahn Gillmor wrote:

> However, I haven't been able to test this properly because i don't
> have any equipment that natively does 7bit serial connections.
>
> I tried it against a grub instance configured with 
>
>  serial --unit=0 --speed=115200 --word=7 --parity=no --stop=1
>
> but was unable to get an active communication (though i don't know how
> well-tested grub's --word=7 option is either).
 
fwiw, i *was* able to test cereal's ability to do 7-bit communications
when the remote terminal was controlled by another screen session
invoked with 115200,cs7.  This doesn't strike me as a really strong
test for interoperability, though, since it's just screen on both
sides.

Any pointers to equipment i could do proper tests on for this?
Anything other than 8n1 seems pretty scarce on the ground, from what
i've seen.

          --dkg
[Message part 2 (application/pgp-signature, inline)]

Information forwarded to debian-bugs-dist@lists.debian.org, Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>:
Bug#487418; Package cereal. Full text and rfc822 format available.

Acknowledgement sent to Marc Haber <mh+debian-bugs@zugschlus.de>:
Extra info received and forwarded to list. Copy sent to Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>. Full text and rfc822 format available.

Message #20 received at 487418@bugs.debian.org (full text, mbox):

From: Marc Haber <mh+debian-bugs@zugschlus.de>
To: Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>
Cc: 487418@bugs.debian.org, cereal@fifthhorseman.net
Subject: Re: Bug#487418: cereal: how to set parity, bit number, stop bits
Date: Mon, 28 Jul 2008 12:49:23 +0200
Hi Daniel,

On Sun, Jun 22, 2008 at 10:49:17AM -0400, Daniel Kahn Gillmor wrote:
> On Sat 2008-06-21 13:33:25 -0400, Marc Haber wrote:
> > To be a fully featured serial console application, one needs the
> > possibility to set serial port parameters other than the baud
> > rate. I have not seen any serial port needing something other than 8
> > bits, no parity, 1 stop bit in a long time, but that feature might
> > be needed in the future.
> 
> Thanks, this is a good suggestion.  Since cereal relies on screen, you
> should be able set 7 bits instead of 8 bits by appending ,cs7 to the
> baud rate.  e.g.
> 
>  cereal-admin create sevenbitcomms /dev/ttyS3 115200,cs7 foo foogroup
> 
> However, I haven't been able to test this properly because i don't
> have any equipment that natively does 7bit serial connections.
> 
> I tried it against a grub instance configured with 
> 
>  serial --unit=0 --speed=115200 --word=7 --parity=no --stop=1
> 
> but was unable to get an active communication (though i don't know how
> well-tested grub's --word=7 option is either).

I used a ser2net as the other side, and 9600,cs7 seems to work just
fine.

> Unfortunately, searching through screen(1) i don't see how to set the
> stop bits or parity of the connection.  Shall i clone this bug and
> reassign the cloned bug to screen, referring to these features?

I think that would be a good idea. I tried sttying the tty to the
appropriate values before starting the cereal session, but tht didn't
seem to work. At least, no communication was possible, and the values
were reset to no parity 1 stopbit after I stopped the cereal session.
So screen does not only not allow setting these parameters, it seems
to set them to hard-coded defaults (which luckly are appropriate for
the vast majority of use cases these days).

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Mannheim, Germany  |  lose things."    Winona Ryder | Fon: *49 621 72739834
Nordisch by Nature |  How to make an American Quilt | Fax: *49 3221 2323190




Information forwarded to debian-bugs-dist@lists.debian.org, Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>:
Bug#487418; Package cereal. Full text and rfc822 format available.

Acknowledgement sent to Marc Haber <mh+debian-bugs@zugschlus.de>:
Extra info received and forwarded to list. Copy sent to Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net>. Full text and rfc822 format available.

Message #25 received at 487418@bugs.debian.org (full text, mbox):

From: Marc Haber <mh+debian-bugs@zugschlus.de>
To: 487418@bugs.debian.org
Cc: cereal@fifthhorseman.net
Subject: Re: Bug#487418: cereal: how to set parity, bit number, stop bits
Date: Mon, 28 Jul 2008 12:50:55 +0200
On Sun, Jun 22, 2008 at 11:05:09AM -0400, Daniel Kahn Gillmor wrote:
> Any pointers to equipment i could do proper tests on for this?
> Anything other than 8n1 seems pretty scarce on the ground, from what
> i've seen.

I guess that cisco routers can be configured to do more exotic
parameters on their console line, but I don't know too exactly how
that is done.

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Mannheim, Germany  |  lose things."    Winona Ryder | Fon: *49 621 72739834
Nordisch by Nature |  How to make an American Quilt | Fax: *49 3221 2323190




Bug 487418 cloned as bug 492741. Request was from Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net> to control@bugs.debian.org. (Mon, 28 Jul 2008 15:06:08 GMT) Full text and rfc822 format available.

Changed Bug title to `screen is unable to set parity or stop bits when attached to a serial console' from `cereal: how to set parity, bit number, stop bits'. Request was from Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net> to control@bugs.debian.org. (Mon, 28 Jul 2008 15:06:10 GMT) Full text and rfc822 format available.

Bug reassigned from package `cereal' to `screen'. Request was from Daniel Kahn Gillmor <dkg-debian.org@fifthhorseman.net> to control@bugs.debian.org. (Mon, 28 Jul 2008 15:06:11 GMT) Full text and rfc822 format available.

Send a report that this bug log contains spam.


Debian bug tracking system administrator <owner@bugs.debian.org>. Last modified: Thu Apr 17 02:02:16 2014; Machine Name: beach.debian.org

Debian Bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.