Bug#420820: no console set IBM p5 server

[Sven Luther <luther@debian.org>]

On Mon, May 14, 2007 at 09:38:25PM +0200, Frans Pop wrote:
> (No need to CC me. I see your replies on the debian-boot mailing list.)
> 
> On Monday 14 May 2007 21:09, Rolf Brudeseth wrote:
> > ~ # /usr/lib/finish-install.d/90console
> [...]
> > + readlink /proc/1560/fd/0
> > + rawconsole=/dev/console
> 
> Thanks. So the debian-installer process thinks a regular console is being 
> used. That means that we do indeed need that redirection information you 
> referred to.
> So, how do we determine which device is actually being used as console?

The information of which console is used is available from the CHRP
device tree. Probably something like :

  /proc/device-tree/chosen/stdout

or

  /proc/device-tree/chosen/linux,stdout-path

(This is from my Apple XServe G5, i don't have the p505 online right
now, and cannot access it until next week), so Rolf, if you could share
the content of your /proc/device-tree/chosen directory, and the content
of those nodes actually of interest ? 

The stdout seems to be a pointer to a node of some kind, while the
linux,stdout-path actually contains the path of the OF device used as
stdout.

This means that you would need something like ofpath or ofpathname to
map it back to the actual /dev/hvc*|hvsi*.

Notice also, that later linuces are able to auto-discover the actual output
device used, and keep it as console, without the need of specifying
console=/dev/*, altough i am not fully sure how this works.

This is rather nice, especially as the actual name of the serial devices
changes for the same hardware depending on how you use it, and the
virtualized ones may even have a phantom /dev/ttyS or /dev/tty
somewhere, since adding /dev/hvc0 in addition to both /dev/ttyS and
/dev/tty on the kernel command line does desactivate the hvc output.

Friendly,

Sven Luther