Re: [PATCH v2 dtc-1.3.0] dtc: Add --strip-disabled option to dtc(v2).
From: Jon Loeliger <hidden>
Date: 2012-08-20 13:25:40
From: Srinivas Kandagatla <redacted> This patch allows dtc to strip out nodes in its output based on status property. Now the dtc has additional long option --strip-disabled to strip all the nodes which do not have status property set to "okay" or "ok". Nodes which do not have status property are not stripped. 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 exclude nodes marked as disabled, doing this way will reduce the size of device tree blob. The size change will be significant once the SOC adds all the possible devices in to the device trees. As there could be 100s of Ips on SOCs but the board actually uses may be 20-25 IP's. However care has to be taken if your boardloader is is updating status property. 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, this is an optional parameter to dtc, Can be used by people who want to strip all the device nodes which do not have status property set to "okay" or "ok".
I don't know. This all strikes me as a means to hack around our total lack of a properly constructed tree based on real data and valid node presence. That is, if we had a better means of constructing your tree in the first place, it would not habve 50% overhead of dead nodes. It should be built in a positive sense, perhaps with includes, or a better system, and not edited out based on questionable negative data. This just seems like a fundamentally wrong approach to me. jdl