Re: defining FEATURE_PACKAGES_* in core-image.bbclass vs image.bbclass

["Robert P. J. Day" <rpjday@crashcourse.ca>]

On Mon, 14 Jul 2014, Rudolf Streif wrote:

> >
> >
> >   then i noticed that the "splash" feature is defined, not in
> > core-image.bbclass, but in the more basic image.bbclass, as is
> > package-management:
> >
> > FEATURE_PACKAGES_package-management = "${ROOTFS_PKGMANAGE}"
> > SPLASH ?= "psplash"
> > FEATURE_PACKAGES_splash = "${SPLASH}"
> >
> > And then there is debug-tweaks for which the hooks are defined in
> image.bbclass including the function zap_empty_root_password but the
> post-processing is added to the variable by core-image.bbclass:
>
> core-image.bbclass: ROOTFS_POSTPROCESS_COMMAND +=
> '${@bb.utils.contains("IMAGE_FEATURES", "debug-tweaks", "",
> "zap_empty_root_password ; ",d)}'
>
> Since image.bbclass also adds the debug-tweaks to the valid image feature
> list
>
> image.bbclass:IMAGE_FEATURES[validitems] += "debug-tweaks read-only-rootfs"

  ... snip ...

  there's something i'll throw in here now that i'm thinking about it.
i've wondered about that very line above -- what is its purpose?

  as i read it, the primary purpose for the variable IMAGE_FEATURES is
to define packagegroups through the use of FEATURE_PACKAGES_* that you
see in core-image.bbclass. (so this is again a bit of weirdness where
code in image.bbclass refers up the "inheritance tree" to stuff found
in core-image.bbclass.)

  however, there are of course some IMAGE_FEATURES that don't
correspond directly to package groups; eg, package-management,
debug-tweaks, read-only-rootfs. so why is "package-management" not
listed in the line:

image.bbclass:IMAGE_FEATURES[validitems] += "debug-tweaks read-only-rootfs"

is that variable flag supposed to list all valid, non-packagegroup
IMAGE_FEATURES?

  i can see that debug-tweaks is processed explicitly in
image.bbclass:

ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "debug-tweaks", "ssh_allow_empty_password; ", "",d)}'
ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "debug-tweaks", "postinst_enable_logging; ", "",d)}'

  but, then again, so is package-management:

ROOTFS_BOOTSTRAP_INSTALL = "${@bb.utils.contains("IMAGE_FEATURES", "package-management", "", "${ROOTFS_PKGMANAGE_BOOTSTRAP}",d)}"

  so why is debug-tweaks assigned to IMAGE_FEATURES[validitems] but
not package-management? oh, wait, i just noticed that image.bbclass
explicitly does this:

FEATURE_PACKAGES_package-management = "${ROOTFS_PKGMANAGE}"

so that package-management *will* be recognized as a valid image
feature here in image.bbclass:

def check_image_features(d):
    valid_features = (d.getVarFlag('IMAGE_FEATURES', 'validitems', True) or "").split()
    valid_features += d.getVarFlags('COMPLEMENTARY_GLOB').keys()
    for var in d:
       if var.startswith("PACKAGE_GROUP_"):
           bb.warn("PACKAGE_GROUP is deprecated, please use FEATURE_PACKAGES instead")
           valid_features.append(var[14:])
       elif var.startswith("FEATURE_PACKAGES_"):
           valid_features.append(var[17:])
    valid_features.sort()

  gaaaaaaaaah! i need more coffee ...

rday

-- 

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

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