[yocto] in kernel manual, should pick another example for KMACHINE

[Rifenbark, Scott M]

I like Nathan's suggestion for the text.  Can someone explain to me though why emenlow is not a good example here?  In the linux-yocto_3.14.bbappend file, KMACHINE_emenlow-noemgd is set equal to "emenlow".  Isn't this equating emenlow-noemgd and emenlow?  I am probably mis-understanding it so I could use some further explanation. 

Thanks, 
Scott

>-----Original Message-----
>From: yocto-bounces at yoctoproject.org [mailto:yocto-
>bounces at yoctoproject.org] On Behalf Of Nathan Rossi
>Sent: Thursday, March 05, 2015 5:48 AM
>To: Robert P. J. Day
>Cc: Yocto discussion list
>Subject: Re: [yocto] in kernel manual, should pick another example for
>KMACHINE
>
>On Thu, Mar 5, 2015 at 10:03 PM, Robert P. J. Day <rpjday at crashcourse.ca>
>wrote:
>>
>>   in section 3.2 of the kernel dev manual, there is a discussion of
>> KMACHINE and how it is *typically* set to the same value as MACHINE,
>> but there are cases where that might not be true; however, the example
>> used to demonstrate this -- emenlow and emenlow-noemgd -- doesn't
>seem
>> appropriate as there is no "emenlow" machine definition file anymore
>> in meta-intel. AFAICT, all of those non-noemgd machine definitions are
>> gone.
>>
>>   in all the layers i have checked out, the only layer where i see
>> KMACHINE covering a number of MACHINE values is meta-xilinx
>> (zynq-based machines). it sounds picky but, when demonstrating some
>> concept, i think it's important that examples used actually exist in
>> the code base in case people want to check.
>
>It comes around a bit due to the nature of different types of hardware. You
>will find that amongst most of the meta-* bsp layers there exists two types of
>MACHINE. You have the layers like meta-xilinx, meta-ti, etc which have
>machines for each board. And then there are the layers like meta-intel which
>have machines for each platform or SoC. There are a number of reasons for
>each way.
>
>At least for Zynq, the kernel can (if you ignore that it has FPGA
>logic) be configured and built the same way for all the boards with device
>trees handling the differences. And as such the configuration is setup for the
>SoC instead of the board. The reason that you actually see KMACHINE
>differences in meta-xilinx is that the layer uses the linux-yocto build flow as
>well as providing an in layer config cache for its targeted KMACHINE's. Which I
>believe is rarely done in bsp layers that inherit linux-yocto for their kernels (or
>bbappend to linux-yocto).
>
>You could re-word the documentation to cover this case with something like:
>"This variable is typically set to the same value as the MACHINE variable
>however in some cases may instead refer to the underlying platform of the
>MACHINE."
>
>Regards,
>Nathan
>
>>
>> rday
>>
>> --
>>
>>
>===========================================================
>=============
>> 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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