[yocto] FW: FW: how the &^$%^%@%^#$ does "file://defconfig" work?

[Rifenbark, Scott M]

I have updated the wording in the "Changing the Configuration" section of the YP Kernel Development Manual to remove implied behavior regarding kernel configuration.  Hopefully, this is clearer.  See http://www.yoctoproject.org/docs/1.5/kernel-dev/kernel-dev.html#changing-the-configuration.  If you have more feedback on it just let me know. 

Thanks, 
Scott

>-----Original Message-----
>From: Rifenbark, Scott M
>Sent: Wednesday, May 08, 2013 5:57 AM
>To: Bruce Ashfield
>Subject: RE: FW: [yocto] how the &^$%^%@%^#$ does "file://defconfig"
>work?
>
>Bruce,
>
>Thanks for the very clear example and the analogy.  I might add a note
>to the section that was confusing Robert.  Sometimes he gets really
>picky on what he reads. But, anytime someone is confused over what is
>written it is worth digging into seeing if it can be cleared up.
>
>Scott
>
>>-----Original Message-----
>>From: Bruce Ashfield [mailto:bruce.ashfield at windriver.com]
>>Sent: Wednesday, May 08, 2013 5:50 AM
>>To: Rifenbark, Scott M
>>Cc: Hart, Darren
>>Subject: Re: FW: [yocto] how the &^$%^%@%^#$ does "file://defconfig"
>>work?
>>
>>On 13-05-08 08:46 AM, Rifenbark, Scott M wrote:
>>> Bruce and Darren,
>>>
>>> Can you comment to me on this thread?  Is what I described to Paul
>>true?
>>
>>It is true. defconfig is the "old" way that kernel configuration is
>>handled. A defconfig is applied to the tree, and then fragments
>>layered on top. Think of it as a specially named, giant fragment, that
>>is always applied first. Otherwise, it's really no different than
>>other fragments.
>>
>>I also followed up with Robert that he was reading to much into the
>>description. Even if you use a defconfig, your final .config will not
>>be exactly that input file, since the kernel configuration system
>>(lkc, not yocto's) can turn config items on and off based on
>>dependencies,
>>and select statements (along with other things).
>>
>>Cheers,
>>
>>Bruce
>>
>>>
>>> Thanks,
>>> Scott
>>>
>>>> -----Original Message-----
>>>> From: Rifenbark, Scott M
>>>> Sent: Wednesday, May 08, 2013 4:23 AM
>>>> To: Eggleton, Paul
>>>> Subject: FW: [yocto] how the &^$%^%@%^#$ does "file://defconfig"
>>work?
>>>>
>>>> Paul,
>>>>
>>>> Could you confirm some of Robert's points down in this thread?
>>>> Basically, if a user does use file://defconfig in the recipes-
>>>> kernel/linux directory, does the build process still modify the
>final
>>>> .config file by applying other fragments?  If so, I need to create
>>some
>>>> more accurate wording.
>>>>
>>>> Thanks,
>>>> Scott
>>>>
>>>>> -----Original Message-----
>>>>> From: yocto-bounces at yoctoproject.org [mailto:yocto-
>>>>> bounces at yoctoproject.org] On Behalf Of Rifenbark, Scott M
>>>>> Sent: Wednesday, April 24, 2013 8:36 AM
>>>>> To: Robert P. J. Day; Yocto discussion list
>>>>> Subject: Re: [yocto] how the &^$%^%@%^#$ does "file://defconfig"
>>work?
>>>>>
>>>>>
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: yocto-bounces at yoctoproject.org [mailto:yocto-
>>>>>> bounces at yoctoproject.org] On Behalf Of Robert P. J. Day
>>>>>> Sent: Wednesday, April 24, 2013 4:51 AM
>>>>>> To: Yocto discussion list
>>>>>> Subject: [yocto] how the &^$%^%@%^#$ does "file://defconfig" work?
>>>>>>
>>>>>>
>>>>>>   been fighting with this for a couple of hours, so i'll start
>with
>>>>>> the short version -- here's the current explanation for "Changing
>>the
>>>>>> Configuration" of your kernel:
>>>>>>
>>>>>> http://www.yoctoproject.org/docs/latest/kernel-dev/kernel-
>>>>>> dev.html#changing-the-configuration
>>>>>>
>>>>>>   the salient bit:
>>>>>>
>>>>>> "If you have a complete Linux kernel .config file you want to use,
>>>>>> copy it to a directory named files, which must be in your layer's
>>>>>> recipes-kernel/linux directory, and name the file "defconfig"."
>>>>>>
>>>>>>   first, that clearly suggests that file://defconfig is to be used
>>>>>> *only* when you have a complete .config file you want to use,
>which
>>>>>> also implies that if you use that, you should not be picking up
>any
>>>>>> other snippets. that's how i read that -- the use of
>>>>>> "file://defconfig" means that that is *exactly* the final form of
>>my
>>>>>> eventual .config file. if that's not true, then that wording needs
>>to
>>>>>> change.
>>>>>>
>>>>>>   also, i've been trying to do just that for a couple hours now,
>>and i
>>>>>> am definitely *not* getting that as my final .config file used for
>>the
>>>>>> kernel configuration. so what should be happening here? thanks.
>>>>>>
>>>>>> rday
>>>>>>
>>>>>> p.s. as i have some spare time between contracts at the moment, i
>>am
>>>>>> going to be going over some of the yocto docs in excruciating
>>detail.
>>>>>> somewhere, scott rifenbark is now thinking, "oh, crap, ..."
>>>>>
>>>>> Your feedback always improves things Robert... no problems.
>>>>>
>>>>>
>>>>>>
>>>>>> --
>>>>>>
>>>>>>
>>======================================================================
>>>> =
>>>>> =
>>>>>> Robert P. J. Day                                 Ottawa, Ontario,
>>>>> CANADA
>>>>>>                         http://crashcourse.ca
>>>>>>
>>>>>> Twitter:
>>>>> http://twitter.com/rpjday
>>>>>> LinkedIn:
>>>>> http://ca.linkedin.com/in/rpjday
>>>>>>
>>======================================================================
>>>> =
>>>>> =
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