[U-Boot] u-boot tools and build system

[Raphael Philipe]

Thank you Wolfgang,

For the especific case of the env tool, One can build it to run on the
host to produce a environment variables binary file for the target
(This can be used while building some image to be written in a sd
card, spi flash or the like). For this specific case I'm in doubt on
how to compile it. I'm trying to compile it for beaglebone black.

I was able to compile it, but I'm not sure if I did it properly.
Moreover I would like to know the role of HOSTCC in it and if it is
correct to access it directly.

I used the following commands:

make am335x_evm_config CROSS_COMPILE=arm-poky-linux-gnueabi-
HOSTCC="gcc " CC="arm-poky-linux-gnueabi-gcc  -march=armv7-a
-mfloat-abi=hard -mfpu=neon -mtune=cortex-a8 "
make env CROSS_COMPILE=arm-poky-linux-gnueabi- HOSTCC="gcc "
CC="arm-poky-linux-gnueabi-gcc  -march=armv7-a -mfloat-abi=hard
-mfpu=neon -mtune=cortex-a8 "

Using this approach, I can compile code for the host that is dependent
on the target architecture.

All of this makes sense?

Thank you.

On Thu, Jan 22, 2015 at 4:10 AM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Raphael Philipe,
>
> In message <CAENGNhddME5v75WTM+u3w68-zAfBTbsrrKFNTjfSpCypKG18aw at mail.gmail.com> you wrote:
>>
>> I'm working on the improvement of the recipes of u-boot in the Poky
>> reference system of Yocto project.
>
> Thanks a lot in advance!
>
>> My questions are:
>>
>> - what is the build system used in u-boot?
>
> It is based on Kbuild in combination with specific scripts (buildman)
> especially for mass-building.  It is tailored to be usable with a
> large variety of tool chains.
>
>> - Does this build system change for building the tools?
>
> No.
>
>> - What do I need to change when compiling the tools for the host
>> architecture and for the target?
>
> Change?  Nothing.  You just run a different command.
>
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> To make this work we'd need a patch, as nobody of us tests this.
> - L. Poettering in https://bugs.freedesktop.org/show_bug.cgi?id=74589