[U-Boot] [U-boot] CONFIG_OF_EMBED question

[Simon Glass]

Hi,

On Fri, Aug 23, 2013 at 11:16 AM, Gerhard Sittig <gsi at denx.de> wrote:
> On Fri, Aug 23, 2013 at 19:35 +0800, TigerLiu at viatech.com.cn wrote:
>>
>> Hi, experts:
>>
>> If i defined CONFIG_OF_EMBED, then:
>>
>> Where could i find _binary_dt_dtb_start's definition?
>>
>> In arch/arm/lib/board.c:
>>
>> gd->fdt_blob = _binary_dt_dtb_start;
>>
>>
>>
>> but i could not find _binary_dt_dtb_start's definition.
>
> Looks like something the linker will resolve while the symbol is
> introduced by something that isn't generated from compiling
> source code.
>
> See the objcopy(1) manpage and search for '_start' there.  This
> appears to be a feature of incorporating BLOBs and data files
> into your executables without taking the detour of generating
> header files, and perfectly fits into what the "embed" name of
> the config option suggests.
>
> So depending on why you are asking (you don't tell what is the
> actual problem you are trying to solve, just which detail you
> currently are digging into), you may want to search the makefiles
> and other build instructions on where a file named "dt.dtb" or
> similar gets referenced.
>
> See the output of `git grep -C 5 'dt.dtb'` -- Makefile and
> dtc/Makefile probably are what you are looking for.

Yes, exactly.

I should add that CONFIG_OF_EMBED is really only there for use with
ICE units or some other situation where you want the DT built in. It
is not for production code.

Regards,
Simon