[RFC/PATCH 2/3] of: add of_lookup_stdout() utility function

Yoder Stuart stuart.yoder at freescale.com
Fri Aug 8 03:28:35 EST 2008


 

> -----Original Message-----
> From: linuxppc-dev-bounces+b08248=freescale.com at ozlabs.org 
> [mailto:linuxppc-dev-bounces+b08248=freescale.com at ozlabs.org] 
> On Behalf Of David Gibson
> Sent: Thursday, August 07, 2008 1:13 AM
> To: Tabi Timur
> Cc: linuxppc-dev at ozlabs.org; paulus at samba.org; miltonm at bga.com
> Subject: Re: [RFC/PATCH 2/3] of: add of_lookup_stdout() 
> utility function
> 
> On Wed, Aug 06, 2008 at 11:46:47AM -0500, Timur Tabi wrote:
> > On Wed, Aug 6, 2008 at 1:02 AM, Grant Likely 
> <grant.likely at secretlab.ca> wrote:
> > > From: Grant Likely <grant.likely at secretlab.ca>
> > >
> > > of_lookup_stdout() is useful for figuring out what device 
> to use as output
> > > for early boot progress messages.  It returns the node 
> pointed to by the
> > > linux,stdout-path property in the chosen node.
> > 
> > I thought linux,stdout-path is deprecated are we're supposed to be
> > using the aliases node instead?
> 
> During the ePAPR process this idea came up - standardising a 'stdout'
> alias that would replace linux,stdout-path in chosen.  However that
> was done in ignorance of the history of the linux,stdout-path property
> and its connection to the stdout ihandle in chosen.  In any case, the
> proposed 'stdout' alias didn't make the final cut for ePAPR, so how to
> address this for flat-tree systems is still an open question.

In the ePAPR discussion I think we generally agreed that
an alias was better than a property under /chosen.  There
were 2 things that caused us to delete the /aliases/stdout.

One was discussions around whether we needed to support
multiple consoles somehow.

The second was the idea that we may need a /aliases/stdin as well.
You could conceptually have stdout be a monitor and a stdin
be a keyboard.

Stuart



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