Re: [ECOS] problem with layered drivers

[Bernard Fouchà <bernard dot fouche at kuantic dot com>]

Hi Michele.

I'm a newbie to eCos, so don't take my word for the Truth ;-). However I 
recently wrote code that fire a thread that uses open() on all available 
/dev/tty? and:
- use select() on all handles returned by open()
- when select() returns because data is available, look for the handle 
that gave the data.
- perform a non blocking read on this handle.
- send traffic to whatever thread needs it, using message boxes.

(you have to configure 'tty-mode serial driver' (CYGPKG_IO_SERIAL_TTY) 
and activate the uarts you need). You also need "support for non 
blocking read and write calls" (CYGPKG_IO_SERIAL_SUPPORT_NONBLOCKING), 
"Enable serial device select support" (CYGPKG_IO_SERIAL_SELECT_SUPPORT) 
and maybe a few others accord to conflicts that configtool may detect). 
Termios are not needed.

The thread performing this job can enforce its own kind of line 
discipline to avoid producing a message per character, but that depends 
on the data expected from the UARTs.

This design is very similar to a multi-thread daemon that would process 
many incoming internet connections on a unix machine and redirect trafic 
to whatever process that needs it (for instance by multiplexing traffic 
on a single socket)

Bernard

Michele Paselli wrote:
> Hi Bernard,
> could you please be more precise? Where can I find the open function 
> and how can I use that?
> Thanks
>
> Michele
>
>   
>   


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