[RFC 3/3] powerpc: Add DTS file for the Motorola PrPMC2800 platform

Mark A. Greer mgreer at mvista.com
Thu Apr 5 02:29:05 EST 2007


On Wed, Apr 04, 2007 at 01:18:41PM +0200, Segher Boessenkool wrote:
> >Agreed.  Dale Farnsworth suggested a 'ranges' type property at the top
> >level that's used for phys->virt mappings.  That is much cleaner IMHO
> >and eliminates the need to parse hash tables or add ioremap code to the
> >bootwrapper.
> 
> I suggest you implement the standard "mmu" binding instead,
> or the part that is relevant to you anyway:
> 
> /chosen/mmu contains the ihandle for an "mmu" node (for
> flat trees, you use a phandle instead);
> 
> that node has properties, quoting from the base OF spec:
> 
> “available”
> The property values are as defined for the standard “reg” format,
> with single-cell virtual addresses. The regions of virtual address
> space denote the virtual address space that is currently unallocated
> by the Open Firmware and is available for use by client programs.
> 
> “existing”
> The value of this property defines the regions of virtual address
> space managed by the MMU in whose package this property is defined
> without regard to whether or not these regions are currently in use.
> The encodings of virt and len are MMU-specific.
> 
> Have a look at the PowerPC binding to find out about that specific
> encoding.

Cool, thanks for the pointer Segher.

Mark



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