On 02/08/2013 03:04 PM, Grant Likely wrote: > On Fri, 08 Feb 2013 15:24:25 -0600, Rob Herring <robherri...@gmail.com> wrote: >> On 02/08/2013 08:45 AM, Grant Likely wrote: >>> On Tue, 5 Feb 2013 12:06:28 -0700, Stephen Warren <swar...@wwwdotorg.org> >>> wrote: >>>> From: Stephen Warren <swar...@nvidia.com> >>>> >>>> Create cmd_dtc_cpp to run the C pre-processor on *.dts file before >>>> passing them to dtc for final compilation. This allows the use of #define >>>> and #include within the .dts file. >>>> >>>> Acked-by: Simon Glass <s...@chromium.org> >>>> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagn...@jcrosoft.com> >>>> Acked-by: Michal Marek <mma...@suse.cz> >>>> Acked-by: Srinivas Kandagatla <srinivas.kandaga...@st.com> >>>> Signed-off-by: Stephen Warren <swar...@nvidia.com> >>> >>> I've applied this and was going to push it out, but I've just thought of >>> a problem that could be a show stopper. Once a dtsp file includes a C >>> header, the contents of that header become part of the Device Tree ABI. >>> If someone changes that file (ie. to renumber a series of #defines) then >>> that will break the binding. We need a way to protect against that. >>> Someone changing a .h file may make the assumption that it is only >>> kernel internal and won't realize that it has external implications. >>> >>> I'm thinking that any dts includes need to be treated in the same way as >>> userspace headers. We could put them into include/uapi and piggy back on >>> the protection already afforded by that directory, or come up with >>> something new. Any thoughts? >> >> Also, we would never be able to separate the dts files from the kernel >> tree without some separation. > > Good point. They better be in a completely separate directory then.
How about arch/*/include/dts/. Both *.dts and kernel code will need to include those headers (so that the kernel can parse the DTB using the same values), so putting the headers right into arch/*/boot/dts/ or arch/*/boot/dts/include/ might not make sense, since then that directory would still have to exist even if/when the .dts files are separated from the kernel. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
