[U-Boot] [PATCH v3 1/2] arch: Make board selection choices optional

[Alexey Brodkin <Alexey.Brodkin@synopsys.com>]

Hi Joe,

On Wed, 2015-05-13 at 10:11 +0900, Masahiro Yamada wrote:
> Hi Joe,
> 
> 2015-05-13 7:12 GMT+09:00 Tom Rini <trini@konsulko.com>:
> 
> > diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> > index c044ad4..85fddd2 100644
> > --- a/arch/arc/Kconfig
> > +++ b/arch/arc/Kconfig
> > @@ -132,6 +132,7 @@ config ARC_CACHE_LINE_SHIFT
> > 
> >  choice
> >         prompt "Target select"
> > +       optional
> > 
> >  config TARGET_DUMMY
> >         bool "Dummy target"
> 
> 
> You do not need to add "optional" to the ARC board select
> because Alexey intentionally added TARGET_DUMMY
> to the top of the board select list.
> 
> This is another solution to not lose any CONFIG_BOARD_
> by savedefconfig although I personally prefer this idea very much.

Looks like I discover an issue that happens with that change.
If one attempts to do something like:
------------------>8------------------
"yes "" | make oldconfig" on defconfig
------------------>8------------------
(that trick is done by automated build frameworks like Buildroot that prefer to
not do "xxx_defconfig" explicitly, but modify that defconfig and later expand it
to a full-scale .config) target won't be set because on prompt you'll see
something like that:
------------------>8------------------
Target select [N/y] (NEW)
------------------>8------------------

See default answer here is No!
Which later on attempt to do a build causes:
------------------>8------------------
$ make
scripts/kconfig/conf --silentoldconfig Kconfig
#
# configuration written to .config
#
  CHK     include/config.h
  UPD     include/config.h
  GEN     include/autoconf.mk
In file included from ./include/common.h:18:0:
include/config.h:5:22: fatal error: configs/.h: No such file or directory
 #include <configs/.h>
                      ^
compilation terminated.
scripts/Makefile.autoconf:72: recipe for target 'include/autoconf.mk' failed
make[1]: *** [include/autoconf.mk] Error 1
------------------>8------------------

If "optional" is removed from "choice -> prompt "Target select"" then
target is selected by default and build runs smoothly.

Any thoughts on how to fix it?

-Alexey