[OpenWrt-Devel] [PATCH v3] Add support for C-style in dtsi files

[Nikolay Martynov]

2015-12-07 11:36 GMT-05:00 Jonas Gorski <jogo at openwrt.org>:
> On 07.12.2015 17:16, Nikolay Martynov wrote:
>> Sorry, I've missed those questions. Let me try answering them.
>>
>> Now also including the list.
>>
>> 2015-12-07 10:39 GMT-05:00 Jonas Gorski <jogo at openwrt.org>:
>>> Hi,
>>>
>>> you still haven't answered my questions:
>>>
>>> On Mon, Dec 7, 2015 at 4:07 PM, Nikolay Martynov <mar.kolya at gmail.com> wrote:
>>>> Current way of compuling dts files involves calling C preprocessor on
>>>> main dts file only. This means that dtsi includes cannot have C-style includes.
>>>
>>> Why not? Shouldn't they get processed as well as long as they are
>>> included with #include, not /include/? Can you give an example that
>>> doesn't work?
>>
>> You are right and this will work.
>> That being said, in my very humble opinion this seems somewhat odd to
>> do this not in a way kernel does it. I.e. it is kind of confusing to
>> introduce include syntax that is different from one used dts.
>> Approach I'm suggesting covers all cases currently used in OpenWrt
>> dts files and doesn't force one to use '#include' for dtsi.
>
> Using #include is exactly how the kernel does it, see e.g:
>
> http://lxr.free-electrons.com/source/arch/arm/boot/dts/armada-370.dtsi#L52
> http://lxr.free-electrons.com/source/arch/metag/boot/dts/tz1090.dtsi
> http://lxr.free-electrons.com/source/arch/mips/boot/dts/ingenic/jz4740.dtsi
>
> (Yes there are examples where /include/ is used, but they are in the
> minority and don't use any macros).

  Does this means that '#include' for dtsi is the new 'standard' and
generally patch replacing '/include/' with '#include' in OpenWrt dts
would be welcomed?
  In 4.3 there are more than 800 places that use '/include/', but I
could not immediately find any example of dtsi including .h and being
included with /include/.

>
>>>> This patch addresses this problem. It uses approach similar to one
>>>> use in linux kernel: it preprocesses all dtsi's in current dir into
>>>> tmp dir and then uses that tmp dir as include dir for main dts compilation.
>>>
>>> I can't find this code in the kernel at all. Can you please point that out?
>> It's in scripts/Makefile.lib, look for cmd_dtc.
>
> That one only produces a list of files the dts includes for Make to
> know when to recompile the dts file, but it does not (pre-)process any
> of the dependencies.
>
> dtc itself is only invoced once per dts file (unless I'm misreading something).
  Hmm, I, of course, might have read it wrong.


-- 
Martynov Nikolay.
Email: mar.kolya at gmail.com
_______________________________________________
openwrt-devel mailing list
openwrt-devel at lists.openwrt.org
https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel