[RFC 3/3] powerpc: Add DTS file for the Motorola PrPMC2800platform

[Yoder Stuart-B08248]

> -----Original Message-----
> From: Josh Boyer [mailto:jwboyer at linux.vnet.ibm.com] 
> Sent: Wednesday, March 28, 2007 1:11 PM
> To: Yoder Stuart-B08248
> Cc: Mark A. Greer; linuxppc-dev; Dale Farnsworth
> Subject: RE: [RFC 3/3] powerpc: Add DTS file for the Motorola 
> PrPMC2800platform
> 
> On Wed, 2007-03-28 at 09:43 -0700, Yoder Stuart-B08248 wrote:
> > Biggest concern is that I see a lot of undocumented device
> > types and properties...
> 
> Yes, but that is a problem in general.
> 
> > > +		virtual-reg = <f1000000>;
> > 
> > What is virtual-reg for?  I gather it is related to the bootwrapper
> > needed virtual addresses for devices reg blocks.  But, I counted
> > 12 instances of the property in this file.  Are all needed by the
> > bootwrapper??
> > 
> > Does anyone where this property came from historically?  If it's
> > specifically for a Linux bootwrapper the name should reflect 
> > that-- linux,bootwrapper-reg-vaddr -- or something...
> 
> It came from a discussion Mark, I, and a few others had on this list a
> few months ago about the requirement for reusing the virtual 
> address set
> up by the firmware for the bootwrapper.  You cannot assume a 1:1
> physical to virtual mapping for things, so the bootwrapper 
> console code
> looks for virtual-reg first and uses that address for it's operations.
> 
> > Based on some offline dicussions I think I know what block-index
> > is, but I'd like to see this property documented in
> > booting-without-of.txt.
> 
> As an aside, there's a lot of stuff that needs updating in
> booting-without-of.txt.  The interrupt mapping it suggests is 
> incorrect,
> some of the entry point stuff is invalid, etc.  There's now several
> properties that are being introduced that aren't in there as well.

Right. I know.  But, should we not try to keep that document as 
up to date as we can?   As new, needed properties are created
they should be documented somewhere, and booting-without-of.txt
seem to be the right place to do it for now.

Stuart