in kernel manual, should pick another example for KMACHINE

in kernel manual, should pick another example for KMACHINE

[Robert P. J. Day]

  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.

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================

Re: in kernel manual, should pick another example for KMACHINE

[Nathan Rossi]

On Thu, Mar 5, 2015 at 10:03 PM, Robert P. J. Day <rpjday@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
> ========================================================================
> --
> _______________________________________________
> yocto mailing list
> yocto@yoctoproject.org
> https://lists.yoctoproject.org/listinfo/yocto

Re: 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@yoctoproject.org [mailto:yocto-
>bounces@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@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
>>
>===========================================================
>===========
>> ==
>> --
>> _______________________________________________
>> yocto mailing list
>> yocto@yoctoproject.org
>> https://lists.yoctoproject.org/listinfo/yocto
>--
>_______________________________________________
>yocto mailing list
>yocto@yoctoproject.org
>https://lists.yoctoproject.org/listinfo/yocto

Re: in kernel manual, should pick another example for KMACHINE

[Bruce Ashfield]

On 15-03-05 11:56 AM, Rifenbark, Scott M wrote:
> 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.
>

The example was a good one, the issue that is being mentioned is
simply that meta-intel has removed the emlow* machine definitions,
so there's no code to use as a concrete addition to the docs.

Bruce

> Thanks,
> Scott
>
>> -----Original Message-----
>> From: yocto-bounces@yoctoproject.org [mailto:yocto-
>> bounces@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@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
>>>
>> ===========================================================
>> ===========
>>> ==
>>> --
>>> _______________________________________________
>>> yocto mailing list
>>> yocto@yoctoproject.org
>>> https://lists.yoctoproject.org/listinfo/yocto
>> --
>> _______________________________________________
>> yocto mailing list
>> yocto@yoctoproject.org
>> https://lists.yoctoproject.org/listinfo/yocto

Re: in kernel manual, should pick another example for KMACHINE

[Robert P. J. Day]

On Thu, 5 Mar 2015, Rifenbark, Scott M wrote:

> 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.

  normally, yes, but there *is* only the emenlow-noemgd machine, there
is no longer an emenlow machine. AIUI, there *used* to be both
machines, both using the same KMACHINE value, and that would have been
a perfect example.

  personally, i think it would be more informative if you had two or
more actual machines mapping to the same KMACHINE value, but that's
just me.

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================

Re: in kernel manual, should pick another example for KMACHINE

[Rifenbark, Scott M]

So I was digging in the meta-xilinx layer and down in recipes-kernel/linux/linux-zynqmp-mainline_3.19.bb there are two KMACHINE lines:

  KMACHINE_ep108-zynqmp ?= "zynqmp"
  KMACHINE_qemuzynqmp ?= "zynqmp"

Given these two lines, this is a good example that shows two machines mapping to the same KMACHINE value?

Scott

>-----Original Message-----
>From: Robert P. J. Day [mailto:rpjday@crashcourse.ca]
>Sent: Thursday, March 05, 2015 9:15 AM
>To: Rifenbark, Scott M
>Cc: Nathan Rossi; Yocto discussion list
>Subject: RE: [yocto] in kernel manual, should pick another example for
>KMACHINE
>
>On Thu, 5 Mar 2015, Rifenbark, Scott M wrote:
>
>> 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.
>
>  normally, yes, but there *is* only the emenlow-noemgd machine, there is
>no longer an emenlow machine. AIUI, there *used* to be both machines,
>both using the same KMACHINE value, and that would have been a perfect
>example.
>
>  personally, i think it would be more informative if you had two or more actual
>machines mapping to the same KMACHINE value, but that's just me.
>
>rday
>
>--
>
>===========================================================
>=============
>Robert P. J. Day                                 Ottawa, Ontario, CANADA
>                        http://crashcourse.ca
>
>Twitter:                                       http://twitter.com/rpjday
>LinkedIn:                               http://ca.linkedin.com/in/rpjday
>===========================================================
>=============

Re: in kernel manual, should pick another example for KMACHINE

[Rifenbark, Scott M]

Probably worth looking over the "Using Kernel Metadata in a Recipe" section (http://www.yoctoproject.org/docs/1.8/kernel-dev/kernel.dev.html#using-kernel-metadata-in-a-recipe).  There have been several small areas touched that have affected what sample code is being talked about, etc.  

>-----Original Message-----
>From: yocto-bounces@yoctoproject.org [mailto:yocto-
>bounces@yoctoproject.org] On Behalf Of Rifenbark, Scott M
>Sent: Thursday, March 05, 2015 9:48 AM
>To: Robert P. J. Day
>Cc: Yocto discussion list
>Subject: Re: [yocto] in kernel manual, should pick another example for
>KMACHINE
>
>So I was digging in the meta-xilinx layer and down in recipes-
>kernel/linux/linux-zynqmp-mainline_3.19.bb there are two KMACHINE lines:
>
>  KMACHINE_ep108-zynqmp ?= "zynqmp"
>  KMACHINE_qemuzynqmp ?= "zynqmp"
>
>Given these two lines, this is a good example that shows two machines
>mapping to the same KMACHINE value?
>
>Scott
>
>>-----Original Message-----
>>From: Robert P. J. Day [mailto:rpjday@crashcourse.ca]
>>Sent: Thursday, March 05, 2015 9:15 AM
>>To: Rifenbark, Scott M
>>Cc: Nathan Rossi; Yocto discussion list
>>Subject: RE: [yocto] in kernel manual, should pick another example for
>>KMACHINE
>>
>>On Thu, 5 Mar 2015, Rifenbark, Scott M wrote:
>>
>>> 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.
>>
>>  normally, yes, but there *is* only the emenlow-noemgd machine, there
>>is no longer an emenlow machine. AIUI, there *used* to be both
>>machines, both using the same KMACHINE value, and that would have been
>>a perfect example.
>>
>>  personally, i think it would be more informative if you had two or
>>more actual machines mapping to the same KMACHINE value, but that's just
>me.
>>
>>rday
>>
>>--
>>
>>==========================================================
>=
>>=============
>>Robert P. J. Day                                 Ottawa, Ontario, CANADA
>>                        http://crashcourse.ca
>>
>>Twitter:                                       http://twitter.com/rpjday
>>LinkedIn:                               http://ca.linkedin.com/in/rpjday
>>==========================================================
>=
>>=============
>--
>_______________________________________________
>yocto mailing list
>yocto@yoctoproject.org
>https://lists.yoctoproject.org/listinfo/yocto