Re: [RFC:PATCH 3.6.0-rc1] dtc: Add -P option to dtc for Pre-Processing.

[David Gibson <dwg@au1.ibm.com>]

On Mon, Aug 13, 2012 at 09:01:53AM +0100, Srinivas KANDAGATLA wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@st.com>
> 
> This patch add pre-processing capablity to dtc based on status property.
> Now the dtc has additional option -P to enable Pre-processing based on
> status property.
> 
> The SOCS have lot of device tree infrastructure files which mark the
> device nodes as disabled and the board level device tree enables them if
> required. However while creating device tree blob, the compiler can
> preprocess the nodes and exclude nodes marked as disabled, doing this
> way will reduce the size of device tree blob.
> 
> In our case this has reduced the blob size from 29K to 15K.
> 
> Also nodes with status="disabled" is are never probed by dt platform bus
> code.
> 
> Again, Preprocessing is optional parameter to dtc.

Hrm.

1) Changes to dtc should be made first against upstream dtc at
git://git.jdl.com/software/dtc.git.  The version in the kernel is just
a snapshot of the upstream tree which is updated periodically.

2) I'm not convinced this filtering-by-status is something that
belongs in dtc, but I'm willing to be persuaded.

3) The name has to change.  "preprocess" is far to general a term for
the very specific function you're implementing here.  Especially when
there are serious discussions ongoing about having dtc use cpp or a
similar preprocessor in a general capacity.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
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