General PTY and CONSOLE question

Joel Sherrill joel.sherrill at
Fri Sep 19 18:43:16 UTC 2008

Thomas Doerfler wrote:
> Gene,
> during startup RTEMS tries to open "dev/console". If you don't a device
> of this name, you will run into trouble. PTY will be initialized later
> (AFAIK), so this can't be a replacement.
Depends on the RTEMS version.  This is the
progression right:

+ in 4.6 /dev/console was required and if open() on it
    failed, it was a fatal error.
+ in 4.7.1, the open could fail without causing a fatal error.
   This made the console optional but open() always got
   pulled in.
+ In 4.8, this routine was refactored so there could be
   a "no-console.c"  optional stub to avoid open() being
+ Basically the same in 4.9.
> Maybe the NULL device can help you as a dummy replacement of the console?
When you had to have /dev/console, you could link /dev/console
to /dev/null and get by.  Now you only need to do that if you print
to stdout and assume that it is automatically setup for you.

> wkr,
> Thomas.
> Gene Smith wrote:
>> Does a PTY driver require the console driver? When I remove
>> CONSOLE_DRIVER_TABLE_ENTRY from the Device_drivers[] array I get no pty
>> login. Are they somehow tied together? Examples I have seen on the list
>> have the both.
>> I need to run with my UART h/w disabled (I can't have it on, I need its
>> I/O ports for other functions). However I would still like the PTY
>> login/shell to be working (for now).
>> The other problem also might be that print[kf] calls are still present
>> in the code. printk still tries to send chars to the uart even when
>> CONSOLE is gone. I am not sure about printf.
>> Thanks,
>> -gene
>> _______________________________________________
>> rtems-users mailing list
>> rtems-users at
> --
> --------------------------------------------
> embedded brains GmbH
> Thomas Doerfler           Obere Lagerstr. 30
> D-82178 Puchheim          Germany
> Tel. : +49-89-18 90 80 79-2
> Fax  : +49-89-18 90 80 79-9
> email: Thomas.Doerfler at
> PGP public key available on request
> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
> _______________________________________________
> rtems-users mailing list
> rtems-users at

Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill at        On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
   Support Available             (256) 722-9985

More information about the users mailing list