serial tty name

[u.kleine-koenig@pengutronix.de (Uwe Kleine-König)]

On Wed, Dec 14, 2011 at 05:10:10PM +0200, Igor Grinberg wrote:
> Hi Richard,
> 
> On 12/14/11 16:43, Richard Zhao wrote:
> > How to map different uart port to ttymxc0 (take imx for example)?
> > 
> > In rootfs, it usually "getty ttymxc0"  to get
> > serial console. And the rootfs may be shared by different boards.
> > Traditionaly way is to set right platform device ID.
> > 
> > But with DT, UART2 always generate ttymxc1, UART3 for ttymxc2. You
> > always needs to modify the getty command when your change another board.
> > 
> > Is there a way to fix it?
> 
> As for fix in userspace, you can spawn getty on every ttymxc*,
> so you will get it always.
> 
> Another (userspace) fix would be:
> Instead of getty, add a script (say getty.sh) which will do something like:
> -----------
> CONSOLE=`cat /proc/cmdline | tr " " "\n" | grep console= | tr "=" " " | tr "," " "`
> TTY=`echo $CONSOLE | cut -d' ' -f 2`
> SPEED=`echo $CONSOLE | cut -d' ' -f 3`
> 
> /sbin/getty -L $TTY $SPEED vt100
> --------------

what about:

	eval "$(sed 's/.*console=\([^,]*\),\([0-9]*\).*/tty=\1; speed=\2/'" /proc/cmdline)"

this should prevent getting a "useless use of cat award".

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |