[U-Boot] [PATCH] kbuild/makefile: allow building host tools separately

[Alexey Brodkin]

Hi Masahiro-san,

On Fri, 2014-03-28 at 15:36 +0900, Masahiro Yamada wrote:
> Hi Alexey,
>
> This may be the similar discussion to
> http://u-boot.10912.n7.nabble.com/U-Boot-could-not-cross-compile-u-boot-tools-td174911.html

It looks not that relevant to me.
For example even before switching U-Boot to Kbuild it was not possible
to build host tools simply without patching sources/headers or
configuring real target. Or I might be missing something here.

> Providing a separate make target seems preferable.
> 
> Maybe like this?
> 
> To build host tools just execute:
> =====
> make tools-only
> =====

Fully agree. I thought about it right after I sent you initial patch.

> And I am not happy about adding ifdef to everywhere.

So do I. But I don't see other way around unfortunately.

> 
> So, how about a patch like this?
> 
> 
> 
> 
> diff --git a/Makefile b/Makefile
> index c744718..12e1075 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -409,7 +409,7 @@ timestamp_h := include/generated/timestamp_autogenerated.h
>  
>  no-dot-config-targets := clean clobber mrproper distclean \
>                          help %docs check% coccicheck \
> -                        ubootversion backup
> +                        ubootversion backup tools-only
>  
>  config-targets := 0
>  mixed-targets  := 0
> @@ -1128,6 +1128,9 @@ checkarmreloc: u-boot
>  env: scripts_basic
>         $(Q)$(MAKE) $(build)=tools/$@
>  
> +tools-only: scripts_basic
> +       $(Q)$(MAKE) $(build)=tools
> +
>  tools-all: export HOST_TOOLS_ALL=y
>  tools-all: env tools ;
>  

Doesn't work for me:
========
$ make tools-only
  HOSTCC  scripts/basic/fixdep
  HOSTCC  tools/aisimage.o
  HOSTCC  tools/crc32.o
  HOSTCC  tools/default_image.o
  HOSTCC  tools/dumpimage.o
In file included from include/version.h:11:0,
                 from tools/dumpimage.c:11:
include/timestamp.h:11:47: fatal error:
generated/timestamp_autogenerated.h: No such file or directory
 #include "generated/timestamp_autogenerated.h"
                                               ^
compilation terminated.
make[1]: *** [tools/dumpimage.o] Error 1
make: *** [tools-only] Error 2
========

-Alexey