Linux kernel recipe override question

Linux kernel recipe override question

[John Weber]

Here is a question someone might be able to quickly answer.

I want to be able to override the SRCREV, SRCBRANCH, and the git repository for
the kernel recipe in local.conf.  I like to do this so that I can do local
hacking on a kernel without having to edit the recipe files themselves, and I
find that managing local.conf is easier when I'm changing SRCREVs a lot.

I've been able to override SRCBRANCH by doing this:

In recipes-kernel/linux/linux-wandboard.inc:

SRCBRANCH ??= "master"

The default is set in recipes-kernel/linux/linux-wandboard_3.10.17.bb:

SRCBRANCH ?= "<the-default-branch>"

Then, in local.conf, I can override it:

SRCBRANCH_linux-wandboard = "<my-local-hacking-branch>"

This works fine for SRCBRANCH. If I do the same thing with SRCREV, it doesn't
seem to work.  I've done this:

In linux-wandboard_3.10.17.bb:

SRCREV ??= "<default big long commit id>"

In local.conf:

SRCREV_linux-wandboard = "<my local branch commit id>"

I always get the checkout of the SRCREV assignment done in the recipe file, not
the one I set in local.conf.

Any idea why?  The only thing I can think of is that SRCREV is evaluated completely before
local.conf settings are evaluated.

John

Re: Linux kernel recipe override question

[Gary Thomas]

On 2014-02-24 12:51, John Weber wrote:
> Here is a question someone might be able to quickly answer.
> 
> I want to be able to override the SRCREV, SRCBRANCH, and the git repository for
> the kernel recipe in local.conf.  I like to do this so that I can do local
> hacking on a kernel without having to edit the recipe files themselves, and I
> find that managing local.conf is easier when I'm changing SRCREVs a lot.
> 
> I've been able to override SRCBRANCH by doing this:
> 
> In recipes-kernel/linux/linux-wandboard.inc:
> 
> SRCBRANCH ??= "master"
> 
> The default is set in recipes-kernel/linux/linux-wandboard_3.10.17.bb:
> 
> SRCBRANCH ?= "<the-default-branch>"
> 
> Then, in local.conf, I can override it:
> 
> SRCBRANCH_linux-wandboard = "<my-local-hacking-branch>"
> 
> This works fine for SRCBRANCH. If I do the same thing with SRCREV, it doesn't
> seem to work.  I've done this:
> 
> In linux-wandboard_3.10.17.bb:
> 
> SRCREV ??= "<default big long commit id>"
> 
> In local.conf:
> 
> SRCREV_linux-wandboard = "<my local branch commit id>"
> 
> I always get the checkout of the SRCREV assignment done in the recipe file, not
> the one I set in local.conf.
> 
> Any idea why?  The only thing I can think of is that SRCREV is evaluated completely before
> local.conf settings are evaluated.

You can't do this in local.conf

The best way is to have another layer with a .bbappend for that recipe.  You can
then override these variables in that file.

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------

Re: Linux kernel recipe override question

[Robin Findley]

On 2014-02-24 12:51, John Weber wrote:
> Here is a question someone might be able to quickly answer.
> 
> I want to be able to override the SRCREV, SRCBRANCH, and the git repository
for
> the kernel recipe in local.conf.  I like to do this so that I can do local
> hacking on a kernel without having to edit the recipe files themselves, and
I
> find that managing local.conf is easier when I'm changing SRCREVs a lot.
> 
> I've been able to override SRCBRANCH by doing this:
> 
> In recipes-kernel/linux/linux-wandboard.inc:
> 
> SRCBRANCH ??= "master"
> 
> The default is set in recipes-kernel/linux/linux-wandboard_3.10.17.bb:
> 
> SRCBRANCH ?= "<the-default-branch>"
> 
> Then, in local.conf, I can override it:
> 
> SRCBRANCH_linux-wandboard = "<my-local-hacking-branch>"
> 
> This works fine for SRCBRANCH. If I do the same thing with SRCREV, it
doesn't
> seem to work.  I've done this:
> 
> In linux-wandboard_3.10.17.bb:
> 
> SRCREV ??= "<default big long commit id>"
> 
> In local.conf:
> 
> SRCREV_linux-wandboard = "<my local branch commit id>"
> 
> I always get the checkout of the SRCREV assignment done in the recipe file,
not
> the one I set in local.conf.
> 
> Any idea why?  The only thing I can think of is that SRCREV is evaluated
completely before
> local.conf settings are evaluated.


John, you were close.  Here's an example from my local.conf:

PREFERRED_VERSION_linux-wandboard = "3.10.17"
SRCBRANCH_pn-linux-wandboard = "wandboard_imx_3.10.17_1.0.0_beta_test"
SRCREV_pn-linux-wandboard = "4299c87fd4d46fd786d1600c57986b1fe164138a"

You may want to double-check if your SRCBRANCH override really did work as you
expected.  I think you need the "_pn-".

-Robin

Re: Linux kernel recipe override question

[John Weber]

Hi Robin,

On 2/24/14, 2:27 PM, Robin Findley wrote:
> On 2014-02-24 12:51, John Weber wrote:
>> Here is a question someone might be able to quickly answer.
>>
>> I want to be able to override the SRCREV, SRCBRANCH, and the git repository
> for
>> the kernel recipe in local.conf.  I like to do this so that I can do local
>> hacking on a kernel without having to edit the recipe files themselves, and
> I
>> find that managing local.conf is easier when I'm changing SRCREVs a lot.
>>
>> I've been able to override SRCBRANCH by doing this:
>>
>> In recipes-kernel/linux/linux-wandboard.inc:
>>
>> SRCBRANCH ??= "master"
>>
>> The default is set in recipes-kernel/linux/linux-wandboard_3.10.17.bb:
>>
>> SRCBRANCH ?= "<the-default-branch>"
>>
>> Then, in local.conf, I can override it:
>>
>> SRCBRANCH_linux-wandboard = "<my-local-hacking-branch>"
>>
>> This works fine for SRCBRANCH. If I do the same thing with SRCREV, it
> doesn't
>> seem to work.  I've done this:
>>
>> In linux-wandboard_3.10.17.bb:
>>
>> SRCREV ??= "<default big long commit id>"
>>
>> In local.conf:
>>
>> SRCREV_linux-wandboard = "<my local branch commit id>"
>>
>> I always get the checkout of the SRCREV assignment done in the recipe file,
> not
>> the one I set in local.conf.
>>
>> Any idea why?  The only thing I can think of is that SRCREV is evaluated
> completely before
>> local.conf settings are evaluated.
>
> John, you were close.  Here's an example from my local.conf:
>
> PREFERRED_VERSION_linux-wandboard = "3.10.17"
> SRCBRANCH_pn-linux-wandboard = "wandboard_imx_3.10.17_1.0.0_beta_test"
> SRCREV_pn-linux-wandboard = "4299c87fd4d46fd786d1600c57986b1fe164138a"
Beautiful.  Thanks for the help.  This works.
>
> You may want to double-check if your SRCBRANCH override really did work as you
> expected.  I think you need the "_pn-".
Yes. In my setup I had modified the assignment of SRCBRANCH to the weakest one 
(??=) in the linux-wandboard.inc file and then set it using a stronger one (?=) 
in the recipe (.bb) file, and then finally set it using the hardest one (=) in 
the local.conf.  I certainly do not have a solid foundation in these assignment 
operators.  :-)

Using this method I was able to remove those other changes, so this is all good 
stuff.  What does the _pn- do?  In other recipes it serves as a short reference 
for packagename, I think.
>
> -Robin
>

Re: Linux kernel recipe override question

[Otavio Salvador]

Hello John,

On Mon, Feb 24, 2014 at 4:51 PM, John Weber <rjohnweber@gmail.com> wrote:
> Here is a question someone might be able to quickly answer.
>
> I want to be able to override the SRCREV, SRCBRANCH, and the git repository
> for
> the kernel recipe in local.conf.  I like to do this so that I can do local
> hacking on a kernel without having to edit the recipe files themselves, and
> I
> find that managing local.conf is easier when I'm changing SRCREVs a lot.
>
> I've been able to override SRCBRANCH by doing this:
>
> In recipes-kernel/linux/linux-wandboard.inc:
>
> SRCBRANCH ??= "master"
>
> The default is set in recipes-kernel/linux/linux-wandboard_3.10.17.bb:
>
> SRCBRANCH ?= "<the-default-branch>"
>
> Then, in local.conf, I can override it:
>
> SRCBRANCH_linux-wandboard = "<my-local-hacking-branch>"

Correct.

> This works fine for SRCBRANCH. If I do the same thing with SRCREV, it
> doesn't
> seem to work.  I've done this:
>
> In linux-wandboard_3.10.17.bb:
>
> SRCREV ??= "<default big long commit id>"

Use ?=

> In local.conf:
>
> SRCREV_linux-wandboard = "<my local branch commit id>"
>
> I always get the checkout of the SRCREV assignment done in the recipe file,
> not
> the one I set in local.conf.
>
> Any idea why?  The only thing I can think of is that SRCREV is evaluated
> completely before
> local.conf settings are evaluated.

The backend sets it to invalid before.

Use ?= and give it a try. If it does not work, please send me the
patch so I can try it at my side.

-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750

Re: Linux kernel recipe override question

[Otavio Salvador]

John,

On Tue, Feb 25, 2014 at 12:59 AM, John Weber <rjohnweber@gmail.com> wrote:
> On 2/24/14, 2:27 PM, Robin Findley wrote:
>>
>> On 2014-02-24 12:51, John Weber wrote:
>>>
>>> Here is a question someone might be able to quickly answer.
>>>
>>> I want to be able to override the SRCREV, SRCBRANCH, and the git
>>> repository
>>
>> for
>>>
>>> the kernel recipe in local.conf.  I like to do this so that I can do
>>> local
>>> hacking on a kernel without having to edit the recipe files themselves,
>>> and
>>
>> I
>>>
>>> find that managing local.conf is easier when I'm changing SRCREVs a lot.
>>>
>>> I've been able to override SRCBRANCH by doing this:
>>>
>>> In recipes-kernel/linux/linux-wandboard.inc:
>>>
>>> SRCBRANCH ??= "master"
>>>
>>> The default is set in recipes-kernel/linux/linux-wandboard_3.10.17.bb:
>>>
>>> SRCBRANCH ?= "<the-default-branch>"
>>>
>>> Then, in local.conf, I can override it:
>>>
>>> SRCBRANCH_linux-wandboard = "<my-local-hacking-branch>"
>>>
>>> This works fine for SRCBRANCH. If I do the same thing with SRCREV, it
>>
>> doesn't
>>>
>>> seem to work.  I've done this:
>>>
>>> In linux-wandboard_3.10.17.bb:
>>>
>>> SRCREV ??= "<default big long commit id>"
>>>
>>> In local.conf:
>>>
>>> SRCREV_linux-wandboard = "<my local branch commit id>"
>>>
>>> I always get the checkout of the SRCREV assignment done in the recipe
>>> file,
>>
>> not
>>>
>>> the one I set in local.conf.
>>>
>>> Any idea why?  The only thing I can think of is that SRCREV is evaluated
>>
>> completely before
>>>
>>> local.conf settings are evaluated.
>>
>>
>> John, you were close.  Here's an example from my local.conf:
>>
>> PREFERRED_VERSION_linux-wandboard = "3.10.17"
>> SRCBRANCH_pn-linux-wandboard = "wandboard_imx_3.10.17_1.0.0_beta_test"
>> SRCREV_pn-linux-wandboard = "4299c87fd4d46fd786d1600c57986b1fe164138a"
>
> Beautiful.  Thanks for the help.  This works.
>
>>
>> You may want to double-check if your SRCBRANCH override really did work as
>> you
>> expected.  I think you need the "_pn-".
>
> Yes. In my setup I had modified the assignment of SRCBRANCH to the weakest
> one (??=) in the linux-wandboard.inc file and then set it using a stronger
> one (?=) in the recipe (.bb) file, and then finally set it using the hardest
> one (=) in the local.conf.  I certainly do not have a solid foundation in
> these assignment operators.  :-)

No; this is wrong.

??= is late setting operator. So basically if noone sets it (either a
?=) it is used. Another difference is that the last evaluated value
for ??= is used.

So:

A ??= "value1"
A ??= "value2"

A is value2

But

A ??= "value1"
A ?= "valuenew"
A ??= "value2"

A is valuenew

?= is weak setting; so:

A ?= "value1"
A ?= "value2"

A is value1.

> Using this method I was able to remove those other changes, so this is all
> good stuff.  What does the _pn- do?  In other recipes it serves as a short
> reference for packagename, I think.

Same here. pn- is a way to target the override to the package itself.
The reason why this works is due BitBake code:

http://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/bitbake/lib/bb/fetch2/__init__.py#n870

But SRCREV_linux-wandboard should work in this case. I'd like to debug
it here if you can send your working patch so we can understand why it
did not.

-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750

Re: Linux kernel recipe override question

[John Weber]

On 2/25/14, 6:20 AM, Otavio Salvador wrote:
> John,
>
> On Tue, Feb 25, 2014 at 12:59 AM, John Weber <rjohnweber@gmail.com> wrote:
>> On 2/24/14, 2:27 PM, Robin Findley wrote:
>>> On 2014-02-24 12:51, John Weber wrote:
>>>> Here is a question someone might be able to quickly answer.
>>>>
>>>> I want to be able to override the SRCREV, SRCBRANCH, and the git
>>>> repository
>>> for
>>>> the kernel recipe in local.conf.  I like to do this so that I can do
>>>> local
>>>> hacking on a kernel without having to edit the recipe files themselves,
>>>> and
>>> I
>>>> find that managing local.conf is easier when I'm changing SRCREVs a lot.
>>>>
>>>> I've been able to override SRCBRANCH by doing this:
>>>>
>>>> In recipes-kernel/linux/linux-wandboard.inc:
>>>>
>>>> SRCBRANCH ??= "master"
>>>>
>>>> The default is set in recipes-kernel/linux/linux-wandboard_3.10.17.bb:
>>>>
>>>> SRCBRANCH ?= "<the-default-branch>"
>>>>
>>>> Then, in local.conf, I can override it:
>>>>
>>>> SRCBRANCH_linux-wandboard = "<my-local-hacking-branch>"
>>>>
>>>> This works fine for SRCBRANCH. If I do the same thing with SRCREV, it
>>> doesn't
>>>> seem to work.  I've done this:
>>>>
>>>> In linux-wandboard_3.10.17.bb:
>>>>
>>>> SRCREV ??= "<default big long commit id>"
>>>>
>>>> In local.conf:
>>>>
>>>> SRCREV_linux-wandboard = "<my local branch commit id>"
>>>>
>>>> I always get the checkout of the SRCREV assignment done in the recipe
>>>> file,
>>> not
>>>> the one I set in local.conf.
>>>>
>>>> Any idea why?  The only thing I can think of is that SRCREV is evaluated
>>> completely before
>>>> local.conf settings are evaluated.
>>>
>>> John, you were close.  Here's an example from my local.conf:
>>>
>>> PREFERRED_VERSION_linux-wandboard = "3.10.17"
>>> SRCBRANCH_pn-linux-wandboard = "wandboard_imx_3.10.17_1.0.0_beta_test"
>>> SRCREV_pn-linux-wandboard = "4299c87fd4d46fd786d1600c57986b1fe164138a"
>> Beautiful.  Thanks for the help.  This works.
>>
>>> You may want to double-check if your SRCBRANCH override really did work as
>>> you
>>> expected.  I think you need the "_pn-".
>> Yes. In my setup I had modified the assignment of SRCBRANCH to the weakest
>> one (??=) in the linux-wandboard.inc file and then set it using a stronger
>> one (?=) in the recipe (.bb) file, and then finally set it using the hardest
>> one (=) in the local.conf.  I certainly do not have a solid foundation in
>> these assignment operators.  :-)
> No; this is wrong.
>
> ??= is late setting operator. So basically if noone sets it (either a
> ?=) it is used. Another difference is that the last evaluated value
> for ??= is used.
>
> So:
>
> A ??= "value1"
> A ??= "value2"
>
> A is value2
>
> But
>
> A ??= "value1"
> A ?= "valuenew"
> A ??= "value2"
>
> A is valuenew
>
> ?= is weak setting; so:
>
> A ?= "value1"
> A ?= "value2"
>
> A is value1.

Thanks for going through this Otavio.  From your explanation, here is what I 
should be doing:

In the linux-wandboard.inc:

SRCBRANCH ??= "master"

In linux-wandboard_3.10.17.bb:

SRCBRANCH ??= "default release source branch"
           ^^^ this is the last evaluated ??= assignment, so it should be taken
SRCREV ?= "default release commit id"

In conf/local.conf:

SRCBRANCH_linux-wandboard = "my local testing branch"
SRCREV_linux-wandboard = "my local testing commit id"

SRCBRANCH works based on experience from trial and error that I've done in the past.
SRCREV does not work, again based on what I've tried.

I'll shoot you a patch to make it easy to test on your end.

John
>> Using this method I was able to remove those other changes, so this is all
>> good stuff.  What does the _pn- do?  In other recipes it serves as a short
>> reference for packagename, I think.
> Same here. pn- is a way to target the override to the package itself.
> The reason why this works is due BitBake code:
>
> http://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/bitbake/lib/bb/fetch2/__init__.py#n870
>
> But SRCREV_linux-wandboard should work in this case. I'd like to debug
> it here if you can send your working patch so we can understand why it
> did not.
>

Re: Linux kernel recipe override question

[Otavio Salvador]

Hello John,

On Tue, Feb 25, 2014 at 11:52 AM, John Weber <rjohnweber@gmail.com> wrote:
>
> On 2/25/14, 6:20 AM, Otavio Salvador wrote:
> SRCBRANCH works based on experience from trial and error that I've done in
> the past.
> SRCREV does not work, again based on what I've tried.
>
> I'll shoot you a patch to make it easy to test on your end.

It makes sense now.

The SRCREV is dealt different because we can use SRCREV_FORMAT.

So when we use multiple Git repositories in same fetcher we can have:

SRCREV_FORMAT = "first_second"

and

SRC_URI = "git://...;name=first \
                   git://...;name=second"

and

SRCREV_first = ...
SRCREV_second = ...

So to handle the pn, we must to use:

SRCREV_pn-<recipe>

or

SRCREV_<name>-pn-<recipe>

I hope it clarifies it now.

Regards,

-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750

Re: Linux kernel recipe override question

[John Weber]

Hi Otavio,

On 2/25/14, 9:34 AM, Otavio Salvador wrote:
> Hello John,
>
> On Tue, Feb 25, 2014 at 11:52 AM, John Weber <rjohnweber@gmail.com> wrote:
>> On 2/25/14, 6:20 AM, Otavio Salvador wrote:
>> SRCBRANCH works based on experience from trial and error that I've done in
>> the past.
>> SRCREV does not work, again based on what I've tried.
>>
>> I'll shoot you a patch to make it easy to test on your end.
> It makes sense now.
>
> The SRCREV is dealt different because we can use SRCREV_FORMAT.
>
> So when we use multiple Git repositories in same fetcher we can have:
>
> SRCREV_FORMAT = "first_second"
>
> and
>
> SRC_URI = "git://...;name=first \
>                     git://...;name=second"
>
> and
>
> SRCREV_first = ...
> SRCREV_second = ...
OK.  I think I understand this.
>
> So to handle the pn, we must to use:
>
> SRCREV_pn-<recipe>
>
> or
>
> SRCREV_<name>-pn-<recipe>
Robin Findley explained where the pn- comes in.  Very handy.
>
> I hope it clarifies it now.
>
> Regards,
>

Re: Linux kernel recipe override question

[Gary Thomas]

On 2014-02-25 08:34, Otavio Salvador wrote:
> Hello John,
> 
> On Tue, Feb 25, 2014 at 11:52 AM, John Weber <rjohnweber@gmail.com> wrote:
>>
>> On 2/25/14, 6:20 AM, Otavio Salvador wrote:
>> SRCBRANCH works based on experience from trial and error that I've done in
>> the past.
>> SRCREV does not work, again based on what I've tried.
>>
>> I'll shoot you a patch to make it easy to test on your end.
> 
> It makes sense now.
> 
> The SRCREV is dealt different because we can use SRCREV_FORMAT.
> 
> So when we use multiple Git repositories in same fetcher we can have:
> 
> SRCREV_FORMAT = "first_second"
> 
> and
> 
> SRC_URI = "git://...;name=first \
>                    git://...;name=second"
> 
> and
> 
> SRCREV_first = ...
> SRCREV_second = ...
> 
> So to handle the pn, we must to use:
> 
> SRCREV_pn-<recipe>
> 
> or
> 
> SRCREV_<name>-pn-<recipe>

Doesn't this need to be
  SRCREV_<name>_pn-<recipe>

The use of '_' and '-' is very particular.

> 
> I hope it clarifies it now.
> 
> Regards,
> 

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------

Re: Linux kernel recipe override question

[Otavio Salvador]

[-- Attachment #1: Type: text/plain, Size: 1205 bytes --]

Hi Gary,

Em 25/02/2014 12:57, "Gary Thomas" <gary@mlbassoc.com> escreveu:
>
> On 2014-02-25 08:34, Otavio Salvador wrote:
> > Hello John,
> >
> > On Tue, Feb 25, 2014 at 11:52 AM, John Weber <rjohnweber@gmail.com>
wrote:
> >>
> >> On 2/25/14, 6:20 AM, Otavio Salvador wrote:
> >> SRCBRANCH works based on experience from trial and error that I've
done in
> >> the past.
> >> SRCREV does not work, again based on what I've tried.
> >>
> >> I'll shoot you a patch to make it easy to test on your end.
> >
> > It makes sense now.
> >
> > The SRCREV is dealt different because we can use SRCREV_FORMAT.
> >
> > So when we use multiple Git repositories in same fetcher we can have:
> >
> > SRCREV_FORMAT = "first_second"
> >
> > and
> >
> > SRC_URI = "git://...;name=first \
> >                    git://...;name=second"
> >
> > and
> >
> > SRCREV_first = ...
> > SRCREV_second = ...
> >
> > So to handle the pn, we must to use:
> >
> > SRCREV_pn-<recipe>
> >
> > or
> >
> > SRCREV_<name>-pn-<recipe>
>
> Doesn't this need to be
>   SRCREV_<name>_pn-<recipe>
>
> The use of '_' and '-' is very particular.
>

Yes, you're right. Thanks for pointing this out.

[-- Attachment #2: Type: text/html, Size: 1882 bytes --]