Re: [Ltib] Using Profiles and Preconfigs

[Stuart Hughes]

Hi Mark,

On 09/01/13 13:58, Mark wrote:
> Hello
> 
> I am looking at using profiles and preconfigs to control builds for different 
> products on the same platform.
> 
> My understanding is that... 
> 
> ...preconfigs are copies of specific defconfig files, i.e. they contain all 
> of the 
> system configuration including toolchain, kernel, user packages etc.
> 
> ...profiles are just the user package configuration sections from defconfig 
> files 
> between the 'Package list' and the 'Target System Configuration' entries.
> 
> My questions are as follows:
> 
> 1) Are my assumptions above correct?

Yes.  Preconfigs are all settings, profile is just a package list.  The
idea is that is you had a package list for a router or some other
device, you could apply that to another platform.

> 
> 2) Do the profiles override the equivalent settings in a preconfig file? i.e. 
> if 
> a package is selected by the preconfig and de-selected by the profile, which 
> takes precedence?

Yes I think so, but it's so long ago I can't be 100% sure.

> 
> 3) Is there any way to create a profile other than just 'carving out' the 
> appropriate package section from a complete defconfig file?

In the bin directory, there are 2 scripts: spit_profile and
splice_profile.

* spit_profile takes the config file (on the command line) as input and
output the profile (package part) of that config.
         spit_profile <.config>

* splice_profile replaces the packages in a defconfig/.config file with
those from the profile file passed on the command line.
        splice_profile <.config> <profile>

> 
> Thanks
> 
> Mark

Regards, Stuart