Serial programming on FreeBSD 6.0 RELEASE

Andrew Falanga af300wsm at
Thu Jun 22 20:05:38 UTC 2006

On 6/22/06, David Kelly <dkelly at> wrote:
> On Thu, Jun 22, 2006 at 12:19:41PM -0600, Andrew Falanga wrote:
> > Derek,
> >
> > No I didn't disable the getty on the port.  To be honest, I didn't know
> one
> > was running.
> Its not going to be running by default. Even if it was then it would be
> on /dev/ttyd1 not /dev/cuad1. What is supposed to happen is that getty
> can listen for incoming on /dev/ttyd1 but if it doesn't have an active
> connection it would be set aside while another comes along on the
> call-out device to use the port. If ttyd1 is busy attempts to open cuad1
> should fail.
> > Second, the errors I'm receiving are:
> >
> > sio1: 2 more silo overflows (total 9)
> > sio1: 280221 more tty-level buffer overflows (total 576898)
> Believe this is saying the data arrived and nobody picked it up.

Yes, I'm sure of this as well.  In fact, this is my problem.  If I run the
receive program that I build, it starts, apparrently configures the port as
I want since the ctor doesn't throw the init error and just sits there until
select times out waiting for data on the file descriptor opened in the same

> One question I have is, why would kermit able to receive/send data
> > across the port?  I don't know if said this in my first message, but I
> > started kermit on both the FreeBSD and Linux machines and was able to
> > send/receive data in either direction.  I didn't disable getty before
> > doing that.
> /dev/cuad1 is rw for uucp:dialer and nothing for anyone else. What ID is
> running your code? Generally one places users who are permitted to use
> the serial ports into group dialer. Furthermore kermit needs the user's
> uucp group permissions in order to create the UUCP lock in the hopes
> that other programs will honor kermit's word that the device is busy.

I did put my user in the dialer group.  I'm not familiar with what you mean
by the uucp group and the UUCP lock.


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