Re: [Ltib] slightly different kernel configs for subplatforms?

[Stuart Hughes]

Hi Gernot,

I can't see a good way.  Fundamentally the tool has no way of knowing
how different one configuration may be (or become), so to me it makes
sense that these independent things be held independently (even if related).

In your case you don't need a sub-platform either, you can take the
approach of some other platforms and just have a selectable list of configs.

Regards, Stuart

Gernot Hillier wrote:
> Good morning!
> 
> Thanks for the quick answer!
> 
> The approach of qs857s with the preconfigs is exactly the thing I have
> now but wanted to avoid. It duplicates the complete defconfig and
> linux-foo.config.
> 
> For qs875s, this approach seems to make sense, as the defconfigs and the
> linux-foo.configs seem to differ substantially.
> 
> In my case, however, the linux-foo.configs only differ in three lines
> and the defconfigs only differ in one line (namely the linux-foo.config
> to be used).
> 
> So I'm currently wasting 47kB only to change three lines for one
> subplatform.
> 
> Therefore, I was looking for a mechanism which would allow to specify
> small deviations for a defconfig and/or a linux-foo.config without
> duplicating it completely.
> 
> Am 24.06.2010 21:09, schrieb Stuart Hughes:
>> Take a look at config/platform/qs875s
>>
>> There's a file in there called preconfigs.lkc, if you define one of
>> these in your platform it enables you to have different configurations.
>>  So you can use this to select different packages and/or kernels and
>> configurations.
>>
>> Unfortunately I haven't got time right now to document this, but if you
>> build and play with it, it should be fairly easy to figure out.
>>
>> Regards, Stuart
>>
>> Gernot Hillier wrote:
>>> Hi there!
>>>
>>> I'm again working on integrating a slightly different mpc837x platform
>>> into LTIB mainline.
>>>
>>> There are three subtypes for this platform (mpc8377/8/9) with slightly
>>> different kernel configurations (two are identical, the third differs in
>>> three kernel options).
>>>
>>> Now I wonder if there's a more elegant solution than adding the same
>>> 35kB of linux-...config to config/platform/xxx three times with only
>>> slight modifications.
>>>
>>> Is there a (simple) possibility to have diffs applied to the kernel
>>> config or to modify kernel configuration manually in the spec file for a
>>> certain platform?
>>>
>>> TIA!
>>>
>