svn commit: r191322 - in head/sys: arm/conf dev/iicbus

[Bernd Walter]

On Tue, Apr 21, 2009 at 08:58:42PM +0200, Rafal Jaworowski wrote:
> On 2009-04-21, at 20:38, M. Warner Losh wrote:
> >In message: <20090421223502.507f0dcf.stas at FreeBSD.org>
> >
> >Consider one kernel.  Two different boards.  Different RTC chips on
> >each of these boards.  Hints loaded from the boot loader.  Now, on one
> >board the ds1672 is used, on the other a ds163x is used.  How does the
> >right driver get attached in that case?
> 
> If these boards are different, they are supposed to have different  
> dedicated hints; doesn't this solve your concerns?

For the same reason we have
hint.ed.0
hint.le.0
...

And not just
hint.eth.0

Each driver needs its own private hints.
You can have a kernel compiled with multiple rtc to support a board
family and just tune the hint for a specific board.
This is embedded stuff, people might want to use board X and add
another rtc.
e.g. the BWCT board has a DS1672, but also an iic header.
For whatever reason someone might want another rtc and simply adds one
to the iic header.
Say that this person has multiple boards in use - some with the special
rtc and the others not.
You can as easily add a DS1672 to a normal PC if the onboard rtc isn't
sufficient for your need.

-- 
B.Walter <bernd at bwct.de> http://www.bwct.de
Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.