Linux program and serial port (5.2.1)

Peter Risdon peter at
Fri Sep 24 07:55:25 PDT 2004

Carlos A. Carnero Delgado wrote:
> Hello,
> On Fri, 24 Sep 2004 10:25:47 +0100, Peter Risdon
> <peter at> wrote:
>>Carlos A. Carnero Delgado wrote:
>>>I have a little program , linux native, that I've managed to run
>>>thanks to the Linux compat layer. However, this program opens
>>>the serial port ttyS1, which doesn't exist as such in 5.2.1.
>>>The question is this: how do I make this program to open the
>>>serial port? (FYI, the device it should open is a random number
>>This is a complete guess, but I'm curious whether it would work:
>>You can make links in the /dev directory to existing devices by using
>>entries in /etc/devfs.conf, so in this case you could add a line like:
>>link    cuaa1   ttyS1
>>This works fine with FreeBSD native applications, so I use links like
>>this for my old serial port palm base, and for a cdrom link. Whether
>>it would work with Linux compatibility stuff, I don't know. But, as I
>>said, I'd be interested to find out.
> Perfect, that worked out OK. However, I'm getting this every second in
> the system log:
>   kernel: sio1: 960 more tty-level buffer overflows (total 126252)
> Have any idea about this?

You might get more informed responses from others. I remember seeing 
these errors frequently on oldish machines using serial port terminal 
adapters and modems, but haven't used one of those for ages and don't 
remember the fix (there was one). Googling for the error gives:

Which suggests that *data is coming in faster than your
program can interpret it.  There isn't much you can do about this other
than try quitting some programs.*

I can add that this was never fatal, just filled up the first console 
screen and /var/log/messages.



the circle squared

network systems and software

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