Check IMAGE_FEATURES content in recipe

Check IMAGE_FEATURES content in recipe

[Piotr Piwko]

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Hi,

I would like to check in my recipe if created image is read-only or not. In
order to do so, I use the following condition which I would inside poky
sources:

if ${@bb.utils.contains('IMAGE_FEATURES', 'read-only-rootfs', 'true',
'false', d)}; then

However it seems that IMAGE_FEATURES variable is not exported to the higher
recipes. I also confirmed it's content by executing:

bitbake my-image -e | grep IMAGE_FEATURES

Is there any possibility to export this variable to my recipe or somehow
check the particular image feature?

Thank you in advance for help.

-- 
Piotr Piwko
http://www.embedded-engineering.pl/

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Re: Check IMAGE_FEATURES content in recipe

[ChenQi]

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Hi Piotr,

VAR set in recipe A cannot be accessed by recipe B.

For 'read-only-rootfs' image feature, tweaks are done in functions 
executed after generating rootfs.
meta/classes/rootfs-postcommands.bbclass:ROOTFS_POSTPROCESS_COMMAND += 
'${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", 
"read_only_rootfs_hook; ", "",d)}'

Can you use a similar approach to solve your problem?

Best Regards,
Chen Qi

On 05/10/2018 03:37 PM, Piotr Piwko wrote:
> Hi,
>
> I would like to check in my recipe if created image is read-only or 
> not. In order to do so, I use the following condition which I would 
> inside poky sources:
>
> if ${@bb.utils.contains('IMAGE_FEATURES', 'read-only-rootfs', 'true', 
> 'false', d)}; then
>
> However it seems that IMAGE_FEATURES variable is not exported to the 
> higher recipes. I also confirmed it's content by executing:
>
> bitbake my-image -e | grep IMAGE_FEATURES
>
> Is there any possibility to export this variable to my recipe or 
> somehow check the particular image feature?
>
> Thank you in advance for help.
>
> -- 
> Piotr Piwko
> http://www.embedded-engineering.pl/
>
>


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Re: Check IMAGE_FEATURES content in recipe

[André Draszik]

Hi,

To expand on that - the idea is that (binary) packages shall not be affected
by the image, meaning that you should be able to install the exact same
(binary) package in different images. If you were able to access image
specific variables inside your package recipe (and change behaviour/contents
of your package based on the image), this wouldn't be possible any more.

In other words, an image is just a collection of a different set / number of
packages to be installed, but each individual package itself is the same for
all images.

Cheers,
Andre'

On Thu, 2018-05-10 at 16:46 +0800, ChenQi wrote:
> Hi Piotr,
> 
> VAR set in recipe A cannot be accessed by recipe B.
> 
> For 'read-only-rootfs' image feature, tweaks are done in functions 
> executed after generating rootfs.
> meta/classes/rootfs-postcommands.bbclass:ROOTFS_POSTPROCESS_COMMAND += 
> '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", 
> "read_only_rootfs_hook; ", "",d)}'
> 
> Can you use a similar approach to solve your problem?
> 
> Best Regards,
> Chen Qi
> 
> On 05/10/2018 03:37 PM, Piotr Piwko wrote:
> > Hi,
> > 
> > I would like to check in my recipe if created image is read-only or 
> > not. In order to do so, I use the following condition which I would 
> > inside poky sources:
> > 
> > if ${@bb.utils.contains('IMAGE_FEATURES', 'read-only-rootfs', 'true', 
> > 'false', d)}; then
> > 
> > However it seems that IMAGE_FEATURES variable is not exported to the 
> > higher recipes. I also confirmed it's content by executing:
> > 
> > bitbake my-image -e | grep IMAGE_FEATURES
> > 
> > Is there any possibility to export this variable to my recipe or 
> > somehow check the particular image feature?
> > 
> > Thank you in advance for help.
> > 
> > -- 
> > Piotr Piwko
> > http://www.embedded-engineering.pl/
> > 
> > 
> 
> 

Re: Check IMAGE_FEATURES content in recipe

[Piotr Piwko]

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czw., 10 maj 2018 o 10:45 ChenQi <Qi.Chen@windriver.com> napisał(a):

> Hi Piotr,
>
> VAR set in recipe A cannot be accessed by recipe B.
>

All right, but what about DISTRO_FEATURES? It is available everywhere, so
maybe there is some possibility to do so ...


> For 'read-only-rootfs' image feature, tweaks are done in functions
> executed after generating rootfs.
> meta/classes/rootfs-postcommands.bbclass:ROOTFS_POSTPROCESS_COMMAND +=
> '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs",
> "read_only_rootfs_hook; ", "",d)}'
>
> Can you use a similar approach to solve your problem?
>

Unfortunately, I can not. I would like to make a pkg_postinst() function of
my package dependent on the rootfs mount mode. It should be different if
the rootfs is going to be mounted as read-only.

-- 
Piotr Piwko
http://www.embedded-engineering.pl/

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Re: Check IMAGE_FEATURES content in recipe

[Burton, Ross]

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On 10 May 2018 at 09:59, Piotr Piwko <piotr.piwko@gmail.com> wrote:

>
>> VAR set in recipe A cannot be accessed by recipe B.
>>
>
> All right, but what about DISTRO_FEATURES? It is available everywhere, so
> maybe there is some possibility to do so ...
>

You need to think about what actually happens.  This is a valid bitbake
call:

$ bitbake image-foo image-bar

image-foo and image-bar both contain recipe-flob.  recipe-flob will be
built *once* to generate the packages, and those packages used to build
both images.  If image-foo is read-only and image-bar is read/write, the
*same packages* will be reused.  recipe-flob has no idea that foo is
read-only and bar is read/write because the IMAGE_FEATURES assignments are
specific to those image recipes.

There are global variables (such as DISTRO_FEATURES) and the *default*
IMAGE_FEATURES is also available globally, but that won't help you here.

Ross

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Re: Check IMAGE_FEATURES content in recipe

[Alexander Kanavin]

On 05/10/2018 11:59 AM, Piotr Piwko wrote:
>     For 'read-only-rootfs' image feature, tweaks are done in functions
>     executed after generating rootfs.
>     meta/classes/rootfs-postcommands.bbclass:ROOTFS_POSTPROCESS_COMMAND
>     += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs",
>     "read_only_rootfs_hook; ", "",d)}'
> 
>     Can you use a similar approach to solve your problem?
> 
> 
> Unfortunately, I can not. I would like to make a pkg_postinst() function 
> of my package dependent on the rootfs mount mode. It should be different 
> if the rootfs is going to be mounted as read-only.

You should be able to move the contents of the pkg_postinst to the hook. 
Actually two hooks: one for read only rootfs, another for read-write. 
Add this to your image recipe:

ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", 
"read-only-rootfs", "piotrs_ro_rootfs_hook; ", "piotrs_rw_rootfs_hook; 
",d)}'


and implement the hook functions accordingly. By the time the hooks are 
executed, the package is already installed, so you can access its files 
as needed.

Alex

Re: Check IMAGE_FEATURES content in recipe

[Piotr Piwko]

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czw., 10 maj 2018 o 13:02 Alexander Kanavin <
alexander.kanavin@linux.intel.com> napisał(a):

> You should be able to move the contents of the pkg_postinst to the hook.
> Actually two hooks: one for read only rootfs, another for read-write.
> Add this to your image recipe:
>
> ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES",
> "read-only-rootfs", "piotrs_ro_rootfs_hook; ", "piotrs_rw_rootfs_hook;
> ",d)}'
>

Actually, I don't create my own recipe but I try to extend the existing one
(busybox), so your propose may be not so easy as it sounds :). Anyway I
understand the problem and proposed solution.

Thank you all for help!.

-- 
Piotr Piwko
http://www.embedded-engineering.pl/

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Re: Check IMAGE_FEATURES content in recipe

[Marcelo E. Magallon]

On Thu, May 10, 2018 at 10:22:34AM +0100, Burton, Ross wrote:

>$ bitbake image-foo image-bar
>
>image-foo and image-bar both contain recipe-flob.  recipe-flob will be
>built *once* to generate the packages, and those packages used to build
>both images.  If image-foo is read-only and image-bar is read/write, the
>*same packages* will be reused.  recipe-flob has no idea that foo is
>read-only and bar is read/write because the IMAGE_FEATURES assignments are
>specific to those image recipes.

When dealing with a somewhat similar problem, what I've done is 
that my-recipe.bb generates two packages (my-package-a, 
my-package-b) and the images select which of the two packages 
they want to use.

Marcelo

Re: Check IMAGE_FEATURES content in recipe

[Paul Eggleton]

On Friday, 11 May 2018 3:06:11 AM NZST Marcelo E. Magallon wrote:
> On Thu, May 10, 2018 at 10:22:34AM +0100, Burton, Ross wrote:
> 
> >$ bitbake image-foo image-bar
> >
> >image-foo and image-bar both contain recipe-flob.  recipe-flob will be
> >built *once* to generate the packages, and those packages used to build
> >both images.  If image-foo is read-only and image-bar is read/write, the
> >*same packages* will be reused.  recipe-flob has no idea that foo is
> >read-only and bar is read/write because the IMAGE_FEATURES assignments are
> >specific to those image recipes.
> 
> When dealing with a somewhat similar problem, what I've done is 
> that my-recipe.bb generates two packages (my-package-a, 
> my-package-b) and the images select which of the two packages 
> they want to use.

Right, that's another solution.

FYI I have covered these in the technical FAQ:

  https://wiki.yoctoproject.org/wiki/Technical_FAQ#How_do_I_change_how_my_recipe_is_built_depending_on_what_image_I.27m_building.3F

(One day we'll figure out how to place this somewhere where people can more
easily find it).

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre