Re: SLIP coexisting with serial data?

[Reinoud Zandijk <reinoud%NetBSD.org@localhost>]

Dear Mouse,

On Sun, Oct 10, 2010 at 04:41:40AM -0400, der Mouse wrote:
> I was looking at improving if_sl.c to support encapsulating "normal"
> serial data on the SLIP's tty as packets, thus merging it into the
> packet stream.  I ran into some problems, but think I can handle them;
> I'm writing to ask if there's any interest from anyone else in this
> sort of thing, in upgrading SLIP to support "normal" serial output.

I've encountered that on a serial protocol in my Arduino work. It worked quite
well i have to say. It worked due to a packet starting with an unique byte. If
the state machine is in this `start of packet mode' all other bytes are
output as received serially. All terminal data sent the other way is treated
the same; its buffered and when the packet is finished it is sent. Trouble
with this is of course that you are limited in your bytes for the console.

I don't know SLIP anymore by heart but maybe you could `invent'/use an IP# of
127.0.0.1 as a special case (or 0.0.0.0) to carry the key/terminal stuff. This
would only need a small change in if_sl.h to filter out the magic destination
inserting it in a tty driver that also buffers output and inserts it into the
SLIP stream with the magic address. On the challenged machine the console
could then be hardwired to this special tty.

Cheers,
Reinoud