CORE_IMAGE_EXTRA_INSTALL has potential to be misleading?

CORE_IMAGE_EXTRA_INSTALL has potential to be misleading?

[Robert P. J. Day]

  was reminded of this as i was perusing some old OE core notes.
remember this from core-image.bbclass?

CORE_IMAGE_BASE_INSTALL = '\
    task-core-boot \
    task-base-extended \
    \
    ${CORE_IMAGE_EXTRA_INSTALL} \
    '

CORE_IMAGE_EXTRA_INSTALL ?= ""

IMAGE_INSTALL ?= "${CORE_IMAGE_BASE_INSTALL}"

  except there are some core image variation recipes
(core-image-minimal-dev.bb, among others) that do things like this:

IMAGE_INSTALL = "task-core-boot ${ROOTFS_PKGMANAGE}"

IMAGE_FEATURES += "dev-pkgs"

IMAGE_LINGUAS = " "

LICENSE = "MIT"

inherit core-image

  note how the explicit assignment to IMAGE_INSTALL in that second
example will copletely override the "IMAGE_INSTALL ?=" in the bbclass
file, at which point ${CORE_IMAGE_EXTRA_INSTALL} will obviously never
be evaluated and included.

  i'm guessing that's exactly what the developer had in mind, but it
seems that has the potential to be really misleading, since a newcomer
might want to create an image based on, say,
core-image-minimal-dev.bb, and *think* that, since it's a variation of
a core image recipe, he can use CORE_IMAGE_EXTRA_INSTALL to add extra
packages to the image.  which clearly won't work.

  i'm sure numerous people will point out that the above works
perfectly well as long as you understand what's going on.  i'm just
suggesting that, sooner or later, someone is going to waste a
considerable amount of time trying to figure out why nothing they
specify with CORE_IMAGE_EXTRA_INSTALL is being added to their image.

  thoughts?

rday

-- 

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

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

Re: CORE_IMAGE_EXTRA_INSTALL has potential to be misleading?

[Paul Eggleton]

On Wednesday 20 June 2012 14:28:40 Robert P. J. Day wrote:
>   was reminded of this as i was perusing some old OE core notes.
> remember this from core-image.bbclass?
> 
> CORE_IMAGE_BASE_INSTALL = '\
>     task-core-boot \
>     task-base-extended \
>     \
>     ${CORE_IMAGE_EXTRA_INSTALL} \
>     '
> 
> CORE_IMAGE_EXTRA_INSTALL ?= ""
> 
> IMAGE_INSTALL ?= "${CORE_IMAGE_BASE_INSTALL}"
> 
>   except there are some core image variation recipes
> (core-image-minimal-dev.bb, among others) that do things like this:
> 
> IMAGE_INSTALL = "task-core-boot ${ROOTFS_PKGMANAGE}"
> 
> IMAGE_FEATURES += "dev-pkgs"
> 
> IMAGE_LINGUAS = " "
> 
> LICENSE = "MIT"
> 
> inherit core-image
> 
>   note how the explicit assignment to IMAGE_INSTALL in that second
> example will copletely override the "IMAGE_INSTALL ?=" in the bbclass
> file, at which point ${CORE_IMAGE_EXTRA_INSTALL} will obviously never
> be evaluated and included.

Right, this is not really ideal. In the case of core-image-minimal(-dev) we're 
trying to be as minimal as reasonably possible, and that includes eliminating 
a bunch of the stuff that core-image.bbclass adds. The easiest way to do this 
is by simply setting IMAGE_INSTALL explicitly.

It seems like core-image-minimal-dev has been a little neglected - at least 
two changes that went into core-image-minimal were not also applied to it, 
including the addition of CORE_IMAGE_EXTRA_INSTALL (or POKY_EXTRA_INSTALL as 
it was known at the time). I'm wondering if a better way for this specific 
recipe to work would just to be to "require core-image-minimal.bb" and then 
set IMAGE_FEATURES += "dev-pkgs" as appropriate.

core-image-minimal* are somewhat special cases, however I do think we do need 
to improve the consistency of all of our image recipes.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre