Re: (Semi-random) thoughts on device tree structure and devfs

[David Young <dyoung%pobox.com@localhost>]

On Wed, Mar 10, 2010 at 01:24:40AM +0900, Masao Uebayashi wrote:
> > We don't need a second mechanism to handle dk(4), do we?  If dk3 should
> > attach to the volume with GUID 60708090-a0b0-c0d0-e0f0-01020304050, let
> > the device properties say so:
> > 
> > <plist version="1.0">
> > <dict>
> >         <key>device-driver</key>
> >         <string>dk</string>
> >         <key>device-unit</key>
> >         <integer>0x3</integer>
> >     <key>guid</key>
> >     <string>60708090-a0b0-c0d0-e0f0-01020304050</string>
> > </dict>
> > </plist>
> 
> Usually GUID is recorded in partition table.  You're viewing things in reverse
> order...

I don't see a problem.  Let the kernel read the partition table,
iterate over the partitions, extract properties from each partition,
try to match a dk to each partition by properties (e.g., guid(dk3)
== guid(partition 7 at sd0)).  If there is a match, take the dk unit
number from the matching property list (e.g., dk3).  If there is no
match, choose a unit number that is used by neither a device_t or a
configuration properties list.

Dave

-- 
David Young             OJC Technologies
dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933