[U-Boot] [RFC] How to move lots of CONFIGs from header files to Kconfig

[Masahiro YAMADA]

Hi.

I've been thinking how to move so many CONFIGs to Kconfig.

First, I want to move many boolean macros such as CONFIG_CMD_*,
because it seems easier than string, int, hex configs.

Roughly, we have two options, I think.



[1] I do this work for all the boards

    I will prepare many entries in Kconfigs and
    also move lots of configs options by a tool.

 Pros:
    - Possible to move many options at one time

 Cons:
    - Cause lots of conflicts
    - It is pointless to touch lots of unmaintained boards
      that might be removed by the end of this year
    - Hard work for me


[2] Each board maintainer takes care of boards he is responsible for.

    Procedure:

    1.  I will create many entries in Kconfigs
        without dependencies ("depends on" and "select")

    2.  Each board maintainer will move config options
        from his board headers to defconfigs  (*)
        (I expect most of active boards will be switched at this step.)

    3.  Many of unmaintained boards ( = not converted to generic board)
        will be removed by the end of this year.

    4.  I will forcibly convert left-over boards.
        These boards are almost inactive, so this conversion
        will not produce much conflicts.

     5.  Implement "depends on" and "select" correctly

       (*)  You can edit  directly configs/foo_defconfig.
       Or you can use Kconfig functions in case you may introduce a typo.

        Run "make foo_defconfig"
        Run "make menuconfig"
        Enable config options you like
        Select "Save".
        Run  "make savedefconfig"
        Run  "mv defconfig configs/foo_defconfig"
        Remove unnecessay CONFIGs from your board header files


  Pros:
     - Reduce the possibility of significant conflicts
     - Avoid needless efforts for unmaintained boards

  Cons:
     - Patch for each board will fly around
     - Take longer time


At first, I was planning to do [1] but it would disturb the
development on SoC subsystems.
I see SUNXI custodians are touching their Kconfigs and defconfigs very often.
[1] would cause conflicts between u-boot/master and u-boot-sunxi/{master,next}.
I also many boards are being dropped these days, which increase the conflicts.



I am thinking [2] is better.
Comments are welcome.



-- 
Best Regards
Masahiro Yamada