new way of writing defconfigs for freescale's powerpc platforms

[Michael Ellerman]

On Thu, 2015-04-09 at 21:52 +0000, Lijun Pan wrote:
> Hi Maintainers,
> 
> We have a proposal for writing the defconfigs for freescale's powperpc platforms in a new way.
> Can you take a look and provide some feedback?
> 
> You know currently we have mpc85xx_defconfig, corenet32_defconfig, bsc913x_defconfig, *fman*_defconfig, etc.
> We are going to extract some common parts from the existing defconfigs, and name it, say, fsl_basic_defconfig.
> Then, we could create some defconfigs targeting specific features or specific platforms.
> Say, features specific: kvm_defconfig, fman_defconfig, etc.
> Platforms specific: p1_defconfig, p2_defcongfig, p4_defconfig, t1_defconfig, t2_defconfig, t2_defconfig, b4_defconfig, etc
> When we want to make a kernel image for p1 platform,
> Using the following steps:
> 
> make ./scripts/kconfig/merge_config.sh arch/powerpc/configs/fsl_basic_config p1_defconfig
> make
> 
> What do you think of this new approach?

I don't like that the user has to manually run merge_config.sh.

How does a user even know that it's an option?

It also breaks scripts that auto build the kernel, which expect to be able to do:

  $ make foo_defconfig
  $ make

Scripts like mine for example :)

  http://kisskb.ellerman.id.au/kisskb/head/8734/

What I'd be happy with is something that does merge_config under the covers. So
a user still runs 'make fsl_plat_foo_defconfig', but under the covers it does a
merge config.

kvmconfig and tinyconfig are implemented that way already, so with a bit more
work hopefully you can do that for arch configs also.

cheers