how to create a new layer

how to create a new layer

[Richard Cagley]

I'd like to create a new machine that inherits from an existing
machine. What's the easiest way to do this?

Looking through the yocto documentation I see "yocot-bsp create" but I
don't seem to have that executable. Do I need to use this or is there
an alternate method?

Re: how to create a new layer

[Robert Calhoun]

On 5/21/14 2:26 PM, "Richard Cagley" <rcagley@gmail.com> wrote:

>I'd like to create a new machine that inherits from an existing
>machine. What's the easiest way to do this?
>
>Looking through the yocto documentation I see "yocot-bsp create" but I
>don't seem to have that executable. Do I need to use this or is there
>an alternate method?

The script is in: poky/scripts/yocto-bsp

You don't really need it. The script creates a directory structure for you
and generates some files, but there is nothing magical about it; you can
create those manually using the meta-yocto-bsp layer as an example.
Machine configs are in poky/meta-yocto-bsp/conf/machine.

To make bitbake use your new layer:
a) add your layer to poky/build/conf/bblayers.conf so that that bitbake
knows what directories to search
b) set your machine name in poky/build/conf/local.conf

I would recommend putting your own layer into git (or scm of choice).
Switching branches on poky will make the build fail if your .bbappends no
longer match up with recipes in oe-core, so it's helpful to be able to
switch between e.g. "a version of my layer that works with branch daisy"
and "a version of my layer that works with branch master".

Rob Calhoun

Re: how to create a new layer

[Richard Cagley]

On Wed, May 21, 2014 at 12:26 PM, Robert Calhoun
<rcalhoun@shotspotter.com> wrote:
>
>
> On 5/21/14 2:26 PM, "Richard Cagley" <rcagley@gmail.com> wrote:
>
>>I'd like to create a new machine that inherits from an existing
>>machine. What's the easiest way to do this?
>>
>>Looking through the yocto documentation I see "yocot-bsp create" but I
>>don't seem to have that executable. Do I need to use this or is there
>>an alternate method?
>
> The script is in: poky/scripts/yocto-bsp
>
> You don't really need it. The script creates a directory structure for you
> and generates some files, but there is nothing magical about it; you can
> create those manually using the meta-yocto-bsp layer as an example.
> Machine configs are in poky/meta-yocto-bsp/conf/machine.
>
> To make bitbake use your new layer:
> a) add your layer to poky/build/conf/bblayers.conf so that that bitbake
> knows what directories to search
> b) set your machine name in poky/build/conf/local.conf
>
> I would recommend putting your own layer into git (or scm of choice).
> Switching branches on poky will make the build fail if your .bbappends no
> longer match up with recipes in oe-core, so it's helpful to be able to
> switch between e.g. "a version of my layer that works with branch daisy"
> and "a version of my layer that works with branch master".
>
> Rob Calhoun
>
oh, I don't think I'm using poky so I guess that's the reason I didn't
find yocto-bsp

I'm using oe-core/meta-xilinx and for testing I've created a new test
layer "meta-me" so my bblayers looks like this

BBLAYERS ?= " \
  /home/rcagley/oe-zed-gcc-min/openembedded-core/meta \
  /home/rcagley/oe-zed-gcc-min/meta-xilinx \
  /home/rcagley/oe-zed-gcc-min/meta-oe/meta-oe \
  /home/rcagley/oe-zed-gcc-min/meta-me \
  "

In my local.conf I have
MACHINE ??= "zedboard-zynq7"

My current main goal is to make my build consume a .bbappend file I
have in meta-me/recipes-kernel/linux.

1.) What is the minimum set of files I need to do this? I'd guess at
least meta-me/conf/local.conf. Anything else?
2.) Do I need to change the machine name? If so, how to I inherit
zedboard-zynq7?

The yocto manuals talk to creating a new layer, but I'm less clear on
how to basically inherit everything.

BTW, thanks for the tip about git/matching branches. That's a good idea.

Re: how to create a new layer

[Philip Balister]

On 05/21/2014 04:05 PM, Richard Cagley wrote:
> On Wed, May 21, 2014 at 12:26 PM, Robert Calhoun
> <rcalhoun@shotspotter.com> wrote:
>>
>>
>> On 5/21/14 2:26 PM, "Richard Cagley" <rcagley@gmail.com> wrote:
>>
>>> I'd like to create a new machine that inherits from an existing
>>> machine. What's the easiest way to do this?
>>>
>>> Looking through the yocto documentation I see "yocot-bsp create" but I
>>> don't seem to have that executable. Do I need to use this or is there
>>> an alternate method?
>>
>> The script is in: poky/scripts/yocto-bsp
>>
>> You don't really need it. The script creates a directory structure for you
>> and generates some files, but there is nothing magical about it; you can
>> create those manually using the meta-yocto-bsp layer as an example.
>> Machine configs are in poky/meta-yocto-bsp/conf/machine.
>>
>> To make bitbake use your new layer:
>> a) add your layer to poky/build/conf/bblayers.conf so that that bitbake
>> knows what directories to search
>> b) set your machine name in poky/build/conf/local.conf
>>
>> I would recommend putting your own layer into git (or scm of choice).
>> Switching branches on poky will make the build fail if your .bbappends no
>> longer match up with recipes in oe-core, so it's helpful to be able to
>> switch between e.g. "a version of my layer that works with branch daisy"
>> and "a version of my layer that works with branch master".
>>
>> Rob Calhoun
>>
> oh, I don't think I'm using poky so I guess that's the reason I didn't
> find yocto-bsp
> 
> I'm using oe-core/meta-xilinx and for testing I've created a new test
> layer "meta-me" so my bblayers looks like this
> 
> BBLAYERS ?= " \
>   /home/rcagley/oe-zed-gcc-min/openembedded-core/meta \
>   /home/rcagley/oe-zed-gcc-min/meta-xilinx \
>   /home/rcagley/oe-zed-gcc-min/meta-oe/meta-oe \
>   /home/rcagley/oe-zed-gcc-min/meta-me \
>   "
> 
> In my local.conf I have
> MACHINE ??= "zedboard-zynq7"
> 
> My current main goal is to make my build consume a .bbappend file I
> have in meta-me/recipes-kernel/linux.
> 
> 1.) What is the minimum set of files I need to do this? I'd guess at
> least meta-me/conf/local.conf. Anything else?

You do not need a per layer local.conf

> 2.) Do I need to change the machine name? If so, how to I inherit
> zedboard-zynq7?

Make a conf/machine/me.conf.

You can use one of the zynq machines as a starting point.

You'll need a conf/layer.conf also.

Philip

> 
> The yocto manuals talk to creating a new layer, but I'm less clear on
> how to basically inherit everything.
> 
> BTW, thanks for the tip about git/matching branches. That's a good idea.
> 

Re: how to create a new layer

[Richard Cagley]

On Wed, May 21, 2014 at 1:31 PM, Philip Balister <philip@balister.org> wrote:
> On 05/21/2014 04:05 PM, Richard Cagley wrote:
>> On Wed, May 21, 2014 at 12:26 PM, Robert Calhoun
>> <rcalhoun@shotspotter.com> wrote:
>>>
>>>
>>> On 5/21/14 2:26 PM, "Richard Cagley" <rcagley@gmail.com> wrote:
>>>
>
>> 2.) Do I need to change the machine name? If so, how to I inherit
>> zedboard-zynq7?
>
> Make a conf/machine/me.conf.
>
> You can use one of the zynq machines as a starting point.
>
> You'll need a conf/layer.conf also.

1.) copied meta-xilinx/conf/machine/zedboard-zynq7.conf to
meta-me/conf/machine/me.conf
2.) changed MACHINE in my build/conf/local.conf to "me"
3.) copied meta-xilinx/conf/layer.conf to meta-me/conf/layer.conf

Now:
1.) in layer.conf should I change "xilinx" to "me"?
2.) What about the new machine file me.conf? Do I need to edit it or
by not editing it does it just inherit everything from the other meta
layer?

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> Openembedded-devel mailing list
> Openembedded-devel@lists.openembedded.org
> http://lists.openembedded.org/mailman/listinfo/openembedded-devel

Re: how to create a new layer

[Paul Eggleton]

On Wednesday 21 May 2014 13:58:07 Richard Cagley wrote:
> On Wed, May 21, 2014 at 1:31 PM, Philip Balister <philip@balister.org>
> wrote:
> > On 05/21/2014 04:05 PM, Richard Cagley wrote:
> >> On Wed, May 21, 2014 at 12:26 PM, Robert Calhoun
> >> <rcalhoun@shotspotter.com> wrote:
> >>> On 5/21/14 2:26 PM, "Richard Cagley" <rcagley@gmail.com> wrote:
> >> 2.) Do I need to change the machine name? If so, how to I inherit
> >> zedboard-zynq7?
> > 
> > Make a conf/machine/me.conf.
> > 
> > You can use one of the zynq machines as a starting point.
> > 
> > You'll need a conf/layer.conf also.
> 
> 1.) copied meta-xilinx/conf/machine/zedboard-zynq7.conf to
> meta-me/conf/machine/me.conf
> 2.) changed MACHINE in my build/conf/local.conf to "me"
> 3.) copied meta-xilinx/conf/layer.conf to meta-me/conf/layer.conf
> 
> Now:
> 1.) in layer.conf should I change "xilinx" to "me"?

Yes

> 2.) What about the new machine file me.conf? Do I need to edit it or
> by not editing it does it just inherit everything from the other meta
> layer?

Since you copied an existing configuration file, all that was in it
previously will still apply. You can change it if you want some values to
be different, of course (I would assume that you would want to edit
it since there wouldn't be much point in going through this exercise if you
didn't.)

One other thing to note - if there are overrides for the previous machine
(e.g. in bbappends you may see _zedboard-zynq7) you should change
these to _me so that they still apply.

You may also find this useful:

http://www.yoctoproject.org/docs/current/dev-manual/dev-manual.html#understanding-and-creating-layers 

Cheers

-- 

Paul Eggleton
Intel Open Source Technology Centre

Re: how to create a new layer

[Richard Cagley]

> One other thing to note - if there are overrides for the previous machine
> (e.g. in bbappends you may see _zedboard-zynq7) you should change
> these to _me so that they still apply.
>

What is the threshold for making a new machine? That is, if I just
have a .bbappend file I want, that should just involve creating a new
layer and putting the bbappend file in the correct location. I
shouldn't have to change anything else correct?

For instance, if I just want to change the kernel configuration with a
frag file I can put linux-xlnx_3.8.bbappedn in
meta-me/recipes-kernel/linux and that's all I need?

I guess I'm just confused at what point I actually need a new machine.

Re: how to create a new layer

[Paul Eggleton]

On Thursday 22 May 2014 15:46:01 Richard Cagley wrote:
> > One other thing to note - if there are overrides for the previous machine
> > (e.g. in bbappends you may see _zedboard-zynq7) you should change
> > these to _me so that they still apply.
> 
> What is the threshold for making a new machine? That is, if I just
> have a .bbappend file I want, that should just involve creating a new
> layer and putting the bbappend file in the correct location. I
> shouldn't have to change anything else correct?
> 
> For instance, if I just want to change the kernel configuration with a
> frag file I can put linux-xlnx_3.8.bbappedn in
> meta-me/recipes-kernel/linux and that's all I need?

Yes, that should be all that is required - no need for your own machine 
configuration in this case.

> I guess I'm just confused at what point I actually need a new machine.

If you want to change the global configuration for the machine substantially 
from that in the original BSP, you may need to create your own machine 
configuration; but for the exact same hardware as the original BSP supports I 
would have thought that in most cases it would not be necessary.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre

Re: how to create a new layer

[Richard Cagley]

On Fri, May 23, 2014 at 12:11 AM, Paul Eggleton
<paul.eggleton@linux.intel.com> wrote:
> On Thursday 22 May 2014 15:46:01 Richard Cagley wrote:
>> > One other thing to note - if there are overrides for the previous machine
>> > (e.g. in bbappends you may see _zedboard-zynq7) you should change
>> > these to _me so that they still apply.
>>
>> What is the threshold for making a new machine? That is, if I just
>> have a .bbappend file I want, that should just involve creating a new
>> layer and putting the bbappend file in the correct location. I
>> shouldn't have to change anything else correct?
>>
>> For instance, if I just want to change the kernel configuration with a
>> frag file I can put linux-xlnx_3.8.bbappedn in
>> meta-me/recipes-kernel/linux and that's all I need?
>
> Yes, that should be all that is required - no need for your own machine
> configuration in this case.
>
>> I guess I'm just confused at what point I actually need a new machine.
>
> If you want to change the global configuration for the machine substantially
> from that in the original BSP, you may need to create your own machine
> configuration; but for the exact same hardware as the original BSP supports I
> would have thought that in most cases it would not be necessary.
>
> Cheers,
> Paul
>
> --
>
> Paul Eggleton
> Intel Open Source Technology Centre

Thanks Paul. I think I got it....or I'm starting to get it.

Re: how to create a new layer

[Philip Balister]

On 05/23/2014 03:11 AM, Paul Eggleton wrote:
> On Thursday 22 May 2014 15:46:01 Richard Cagley wrote:
>>> One other thing to note - if there are overrides for the previous machine
>>> (e.g. in bbappends you may see _zedboard-zynq7) you should change
>>> these to _me so that they still apply.
>>
>> What is the threshold for making a new machine? That is, if I just
>> have a .bbappend file I want, that should just involve creating a new
>> layer and putting the bbappend file in the correct location. I
>> shouldn't have to change anything else correct?
>>
>> For instance, if I just want to change the kernel configuration with a
>> frag file I can put linux-xlnx_3.8.bbappedn in
>> meta-me/recipes-kernel/linux and that's all I need?
> 
> Yes, that should be all that is required - no need for your own machine 
> configuration in this case.
> 
>> I guess I'm just confused at what point I actually need a new machine.
> 
> If you want to change the global configuration for the machine substantially 
> from that in the original BSP, you may need to create your own machine 
> configuration; but for the exact same hardware as the original BSP supports I 
> would have thought that in most cases it would not be necessary.

Basically, I make a machine whenever I will have hardware specific
drivers, kernel configs, and device trees.

Philip


> 
> Cheers,
> Paul
>