Re: [PATCH v4] kernel: Add support for multiple kernel packages

[Haris Okanovic <haris.okanovic@ni.com>]

On 07/19/2017 10:56 AM, Wold, Saul wrote:
> On Tue, 2017-07-18 at 08:34 -0500, Haris Okanovic wrote:
>>
>> On 07/17/2017 03:31 PM, Wold, Saul wrote:
>>>
>>> On Wed, 2017-07-05 at 12:33 -0500, Haris Okanovic wrote:
>>>>
>>>> Some distros may want to provide alternate kernel "flavors" via
>>>> feeds
>>>> or
>>>> within bootable images. For example, readily available builds
>>>> which
>>>> provide certain diagnostic features can enable developers and
>>>> testers
>>>> to
>>>> more quickly resolve issues by avoiding lengthy kernel builds.
>>>>
>>>> This change allows for building multiple flavors of the kernel
>>>> and
>>>> module packages by templatizing kernel package names via a new
>>>> KERNEL_PACKAGE_NAME variable in kernel.bbclass. It defaults to
>>>> the
>>>> old
>>>> name of "kernel", but can be overridden by certain recipes
>>>> providing
>>>> alternate kernel flavors.
>>>>
>>>> To maintain compatibility, recipes providing alternate kernel
>>>> flavors
>>>> cannot be the "preferred provider" for virtual/kernel. This is
>>>> because
>>>> OE puts the preferred provider's build and source at
>>>> "tmp-glibc/work-shared/$MACHINE/kernel-build-artifacts/" and
>>>> "tmp-glibc/work-shared/$MACHINE/kernel-source/" instead of
>>>> "tmp-glibc/work/*/$PN/" like other recipes. Therefore, recipes
>>>> using
>>>> the
>>>> default KERNEL_PACKAGE_NAME="kernel" follows the old semantics --
>>>> build
>>>> in the old location and may be preferred provider -- while
>>>> recipes
>>>> using
>>>> all other KERNEL_PACKAGE_NAME's build from the normal WORKDIR and
>>>> don't
>>>> provide "virtual/kernel".
>>>>
>>>> Testing:
>>>>    1. Prepended `KERNEL_PACKAGE_NAME = "tiny-linux"` to
>>>>       linux-yocto-tiny_4.9.bb so that it may build alongside
>>>>       the main kernel.
>>>>    2. `bitbake linux-yocto linux-yocto-tiny` to build both kernel
>>>> flavors.
>>>>    3. Verified image and modules IPKs exist for both:
>>>>       tmp-glibc/deploy/ipk/qemux86/kernel-* for linux-yocto
>>>>       tmp-glibc/deploy/ipk/qemux86/tiny-linux* for linux-yocto-
>>>> tiny
>>>>    4. Verified linux-yocto is the "preferred provider", and was
>>>> built
>>>> in
>>>>       shared directory: tmp-glibc/work-shared/qemux86/kernel-*
>>>>    5. Appended `CORE_IMAGE_BASE_INSTALL += "tiny-linux"` to
>>>>       core-image-base.bb to include both kernel flavors.
>>>>    6. `bitbake core-image-base` to build an image.
>>>>    7. Verified image contains two bzImage's under /boot/, with
>>>>       "yocto-standard" selected to boot via symlink.
>>>>
>>>> Discussion thread:
>>>> http://lists.openembedded.org/pipermail/openembedded-core/2015-De
>>>> cemb
>>>> er/thread.html#114122
>>>>
>>>> Signed-off-by: Ioan-Adrian Ratiu <adrian.ratiu@ni.com>
>>>> Signed-off-by: Gratian Crisan <gratian.crisan@ni.com>
>>>> Signed-off-by: Haris Okanovic <haris.okanovic@ni.com>
>>>> Coauthored-by: Gratian Crisan <gratian.crisan@ni.com>
>>>> Coauthored-by: Haris Okanovic <haris.okanovic@ni.com>
>>>> Coauthored-by: Josh Hernstrom <josh.hernstrom@ni.com>
>>>> ---
>>>> [PATCH v2] Change STAGING_KERNEL_DIR and STAGING_KERNEL_BUILDDIR
>>>> to
>>>> the
>>>> "work" directory in alternate kernel builds, instead of "work-
>>>> shared",
>>>> so
>>>> that the two builds don't clobber each other.
>>>>
>>>> [PATCH v3] An updated version of this change rebased onto the
>>>> current
>>>> OE-core master. Changes:
>>>>    * Remove PREFERRED_PROVIDER check in linux-yocto.inc in
>>>> alternate
>>>>      kernel builds, since alternate kernels aren't the
>>>>      PREFERRED_PROVIDER for virtual/kernel by definition.
>>>>    * Remove "virtual/kernel" from PROVIDES in alternate kernel
>>>> builds.
>>>>
>>>> [PATCH v4] Another rebase onto master; no functional change.
>>>> Improved description and testing steps.
>>>
>>> So I finally had a chance to get back to this and test build with
>>> it, I
>>> saw the following WARNING, which lead to the ERROR:
>>>
>>> WARNING: Variable key FILES_${PN}-dev (${includedir}
>>> ${FILES_SOLIBSDEV}
>>> ${libdir}/*.la ${libdir}/*.o ${libdir}/pkgconfig
>>> ${datadir}/pkgconfig
>>> ${datadir}/aclocal ${base_libdir}/*.o ${libdir}/${BPN}/*.la
>>> ${base_libdir}/*.la) replaces original key FILES_linux-yocto-dev
>>> (/boot/System.map* /boot/Module.symvers* /boot/config*
>>> ${KERNEL_SRC_PATH}
>>> ${nonarch_base_libdir}/modules/${KERNEL_VERSION}/build).
>>> ERROR: linux-yocto-4.10.17+gitAUTOINC+e92bd55409_6648a34e00-r0
>>> do_package: QA Issue: linux-yocto: Files/directories were installed
>>> but
>>> not shipped in any package:
>>>     /boot/System.map-4.10.17-yocto-standard
>>>     /boot/Module.symvers-4.10.17-yocto-standard
>>>     /boot/config-4.10.17-yocto-standard
>>> Please set FILES such that these items are packaged. Alternatively
>>> if
>>> they are unneeded, avoid installing them or delete them within
>>> do_install.
>>> linux-yocto: 3 installed and not shipped files. [installed-vs-
>>> shipped]
>>> ERROR: linux-yocto-4.10.17+gitAUTOINC+e92bd55409_6648a34e00-r0
>>> do_package: Fatal QA errors found, failing task.
>>> ERROR: linux-yocto-4.10.17+gitAUTOINC+e92bd55409_6648a34e00-r0
>>> do_package: Function failed: do_package
>>>
>>> Something seems to be causing the FILES_linux-yocto-dev info to be
>>> overridden, I have not tracked down the culprit yet.
>>>
>>
>> `FILES_linux-yocto-dev` is set to the default value from OE's
>> bitbake.conf. `FILES_kernel-dev` on the other hand is set by
>> kernel.bbclass; when `KERNEL_PACKAGE_NAME` expands to `kernel`.
>>
>> I think the real issue here is that QA checks care about
>> `FILES_${PN}-dev` at all even though that particular package name
>> isn't
>> listed in `PACKAGES` variable. I.e. `FILES_${PN}-dev` should be
>> disregarded since the `linux-yocto` recipe doesn't create package
>> `${PN}-dev`.
>>
>> Thoughts?
>>
> It's hard to special case this. After you sent this, I realized what I
> did was set the KERNEL_PACKAGE_NAME to linux-yocto and because the
> KERNEL_PACKAGE_NAME matched the actual recipe name we got the strange
> ${PN} interaction, we might be able to add a test to flag that as an
> error or warning in the kernel.bbclass.
> 

Ah, I see what you mean now. There appears to be a bug in 
lib.bb.data.expandKeys(), where variables name are expanded 
alphabetically instead of definition order. Filed bug 
https://bugzilla.yoctoproject.org/show_bug.cgi?id=11905 for the issue; 
see example.

Unfortunately, I've not been able to workaround it yet. Adding a warning 
when `KERNEL_PACKAGE_NAME == PN` until bug # 11905 is resolved.

Posting a PATCH v5 shortly.

> I am also seeing an issue when I build a 4.9 kernel and then set-up a
> 4.10 kernel with the kernel-abiversion getting mis-matched from the
> depmodwrapper.  Have you tested with different versions?  I know it
> should work with a old kernel/userspace -> new kernel, but not from a
> new kernel/userspace -> old kernel.
>
I built linux-yocto-tiny version 4.9 and linux-yocto version 4.10 in 
parallel in the aforementioned test procedure. I'm not sure what you 
mean by "old kernel/userspace -> new kernel, but not from a
 > new kernel/userspace -> old kernel". Can you send me your build 
procedure -- I.e. sequence of bitbake commands?

> Sau!
> 
> 
>>>
>>> Sau!
>>>
>>>>
>>>> ---
>>>>    meta/classes/kernel-module-split.bbclass  |  9 ++--
>>>>    meta/classes/kernel.bbclass               | 85
>>>> ++++++++++++++++++---
>>>> ----------
>>>>    meta/conf/documentation.conf              |  1 +
>>>>    meta/recipes-kernel/linux/linux-dtb.inc   |  2 +-
>>>>    meta/recipes-kernel/linux/linux-yocto.inc |  2 +-
>>>>    5 files changed, 59 insertions(+), 40 deletions(-)
>>>>
>>>> diff --git a/meta/classes/kernel-module-split.bbclass
>>>> b/meta/classes/kernel-module-split.bbclass
>>>> index 1035525dac..9716c5937b 100644
>>>> --- a/meta/classes/kernel-module-split.bbclass
>>>> +++ b/meta/classes/kernel-module-split.bbclass
>>>> @@ -30,7 +30,7 @@ do_install_append() {
>>>>    
>>>>    PACKAGESPLITFUNCS_prepend = "split_kernel_module_packages "
>>>>    
>>>> -KERNEL_MODULES_META_PACKAGE ?= "kernel-modules"
>>>> +KERNEL_MODULES_META_PACKAGE ?= "${KERNEL_PACKAGE_NAME}-modules"
>>>>    
>>>>    KERNEL_MODULE_PACKAGE_PREFIX ?= ""
>>>>    KERNEL_MODULE_PACKAGE_SUFFIX ?= "-${KERNEL_VERSION}"
>>>> @@ -129,16 +129,19 @@ python split_kernel_module_packages () {
>>>>               postfix = format.split('%s')[1]
>>>>               d.setVar('RPROVIDES_' + pkg, pkg.replace(postfix,
>>>> ''))
>>>>    
>>>> +    kernel_package_name = d.getVar("KERNEL_PACKAGE_NAME", True)
>>>> +    kernel_version = d.getVar("KERNEL_VERSION", True)
>>>> +
>>>>        module_regex = '^(.*)\.k?o$'
>>>>    
>>>>        module_pattern_prefix =
>>>> d.getVar('KERNEL_MODULE_PACKAGE_PREFIX')
>>>>        module_pattern_suffix =
>>>> d.getVar('KERNEL_MODULE_PACKAGE_SUFFIX')
>>>> -    module_pattern = module_pattern_prefix + 'kernel-module-%s'
>>>> +
>>>> module_pattern_suffix
>>>> +    module_pattern = module_pattern_prefix + kernel_package_name
>>>> +
>>>> '-module-%s' + module_pattern_suffix
>>>>    
>>>>        postinst = d.getVar('pkg_postinst_modules')
>>>>        postrm = d.getVar('pkg_postrm_modules')
>>>>    
>>>> -    modules = do_split_packages(d,
>>>> root='${nonarch_base_libdir}/modules', file_regex=module_regex,
>>>> output_pattern=module_pattern, description='%s kernel module',
>>>> postinst=postinst, postrm=postrm, recursive=True,
>>>> hook=frob_metadata,
>>>> extra_depends='kernel-%s' % (d.getVar("KERNEL_VERSION")))
>>>> +    modules = do_split_packages(d,
>>>> root='${nonarch_base_libdir}/modules', file_regex=module_regex,
>>>> output_pattern=module_pattern, description='%s kernel module',
>>>> postinst=postinst, postrm=postrm, recursive=True,
>>>> hook=frob_metadata,
>>>> extra_depends='%s-%s' % (kernel_package_name, kernel_version))
>>>>        if modules:
>>>>            metapkg = d.getVar('KERNEL_MODULES_META_PACKAGE')
>>>>            d.appendVar('RDEPENDS_' + metapkg, ' '+'
>>>> '.join(modules))
>>>> diff --git a/meta/classes/kernel.bbclass
>>>> b/meta/classes/kernel.bbclass
>>>> index 7670c7107a..7fa4509961 100644
>>>> --- a/meta/classes/kernel.bbclass
>>>> +++ b/meta/classes/kernel.bbclass
>>>> @@ -1,6 +1,8 @@
>>>>    inherit linux-kernel-base kernel-module-split
>>>>    
>>>> -PROVIDES += "virtual/kernel"
>>>> +KERNEL_PACKAGE_NAME ??= "kernel"
>>>> +
>>>> +PROVIDES += "${@ "virtual/kernel" if
>>>> (d.getVar("KERNEL_PACKAGE_NAME", True) == "kernel") else "" }"
>>>>    DEPENDS += "virtual/${TARGET_PREFIX}binutils
>>>> virtual/${TARGET_PREFIX}gcc kmod-native bc-native lzop-native"
>>>>    PACKAGE_WRITE_DEPS += "depmodwrapper-cross virtual/update-
>>>> alternatives-native"
>>>>    
>>>> @@ -33,10 +35,23 @@ KERNEL_VERSION_PKG_NAME[vardepvalue] =
>>>> "${LINUX_VERSION}"
>>>>    
>>>>    python __anonymous () {
>>>>    
>>>> +    # The default kernel recipe builds in a shared location
>>>> defined
>>>> by
>>>> +    # bitbake/distro confs: STAGING_KERNEL_DIR and
>>>> STAGING_KERNEL_BUILDDIR.
>>>> +    # Set these variables to directories under ${WORKDIR} in
>>>> alternate
>>>> +    # kernel recipes (I.e. where KERNEL_PACKAGE_NAME != kernel)
>>>> so
>>>> that they
>>>> +    # may build in parallel with the default kernel without
>>>> clobbering.
>>>> +    if d.getVar("KERNEL_PACKAGE_NAME", True) != "kernel":
>>>> +        workdir = d.getVar("WORKDIR", True)
>>>> +        sourceDir = os.path.join(workdir, 'kernel-source')
>>>> +        artifactsDir = os.path.join(workdir, 'kernel-build-
>>>> artifacts')
>>>> +        d.setVar("STAGING_KERNEL_DIR", sourceDir)
>>>> +        d.setVar("STAGING_KERNEL_BUILDDIR", artifactsDir)
>>>> +
>>>>        # Merge KERNEL_IMAGETYPE and KERNEL_ALT_IMAGETYPE into
>>>> KERNEL_IMAGETYPES
>>>>        type = d.getVar('KERNEL_IMAGETYPE') or ""
>>>>        alttype = d.getVar('KERNEL_ALT_IMAGETYPE') or ""
>>>>        types = d.getVar('KERNEL_IMAGETYPES') or ""
>>>> +    kname = d.getVar('KERNEL_PACKAGE_NAME', True) or "kernel"
>>>>        if type not in types.split():
>>>>            types = (type + ' ' + types).strip()
>>>>        if alttype not in types.split():
>>>> @@ -53,22 +68,22 @@ python __anonymous () {
>>>>            typelower = type.lower()
>>>>            imagedest = d.getVar('KERNEL_IMAGEDEST')
>>>>    
>>>> -        d.appendVar('PACKAGES', ' ' + 'kernel-image-' +
>>>> typelower)
>>>> +        d.appendVar('PACKAGES', ' %s-image-%s' % (kname,
>>>> typelower))
>>>>    
>>>> -        d.setVar('FILES_kernel-image-' + typelower, '/' +
>>>> imagedest
>>>> + '/' + type + '-${KERNEL_VERSION_NAME}')
>>>> +        d.setVar('FILES_' + kname + '-image-' + typelower, '/' +
>>>> imagedest + '/' + type + '-${KERNEL_VERSION_NAME}')
>>>>    
>>>> -        d.appendVar('RDEPENDS_kernel-image', ' ' + 'kernel-
>>>> image-' +
>>>> typelower)
>>>> +        d.appendVar('RDEPENDS_%s-image' % kname, ' %s-image-%s'
>>>> %
>>>> (kname, typelower))
>>>>    
>>>> -        d.setVar('PKG_kernel-image-' + typelower, 'kernel-image-
>>>> ' +
>>>> typelower + '-${KERNEL_VERSION_PKG_NAME}')
>>>> +        d.setVar('PKG_%s-image-%s' % (kname,typelower), '%s-
>>>> image-
>>>> %s-${KERNEL_VERSION_PKG_NAME}' % (kname, typelower))
>>>>    
>>>> -        d.setVar('ALLOW_EMPTY_kernel-image-' + typelower, '1')
>>>> +        d.setVar('ALLOW_EMPTY_%s-image-%s' % (kname, typelower),
>>>> '1')
>>>>    
>>>>            priority = d.getVar('KERNEL_PRIORITY')
>>>>            postinst = '#!/bin/sh\n' + 'update-alternatives --
>>>> install /'
>>>> + imagedest + '/' + type + ' ' + type + ' ' + type + '-
>>>> ${KERNEL_VERSION_NAME} ' + priority + ' || true' + '\n'
>>>> -        d.setVar('pkg_postinst_kernel-image-' + typelower,
>>>> postinst)
>>>> +        d.setVar('pkg_postinst_' + kname + '-image-' +
>>>> typelower,
>>>> postinst)
>>>>    
>>>>            postrm = '#!/bin/sh\n' + 'update-alternatives --remove'
>>>> + '
>>>> ' + type + ' ' + type + '-${KERNEL_VERSION_NAME} || true' + '\n'
>>>> -        d.setVar('pkg_postrm_kernel-image-' + typelower, postrm)
>>>> +        d.setVar('pkg_postrm_%s-image-%s' % (kname, typelower),
>>>> postrm)
>>>>    
>>>>        image = d.getVar('INITRAMFS_IMAGE')
>>>>        if image:
>>>> @@ -126,9 +141,9 @@ base_do_unpack_append () {
>>>>    
>>>>    inherit kernel-arch deploy
>>>>    
>>>> -PACKAGES_DYNAMIC += "^kernel-module-.*"
>>>> -PACKAGES_DYNAMIC += "^kernel-image-.*"
>>>> -PACKAGES_DYNAMIC += "^kernel-firmware-.*"
>>>> +PACKAGES_DYNAMIC += "^${KERNEL_PACKAGE_NAME}-module-.*"
>>>> +PACKAGES_DYNAMIC += "^${KERNEL_PACKAGE_NAME}-image-.*"
>>>> +PACKAGES_DYNAMIC += "^${KERNEL_PACKAGE_NAME}-firmware-.*"
>>>>    
>>>>    export OS = "${TARGET_OS}"
>>>>    export CROSS_COMPILE = "${TARGET_PREFIX}"
>>>> @@ -371,9 +386,9 @@ do_shared_workdir_setscene () {
>>>>    
>>>>    emit_depmod_pkgdata() {
>>>>    	# Stash data for depmod
>>>> -	install -d ${PKGDESTWORK}/kernel-depmod/
>>>> -	echo "${KERNEL_VERSION}" > ${PKGDESTWORK}/kernel-
>>>> depmod/kernel-abiversion
>>>> -	cp ${B}/System.map ${PKGDESTWORK}/kernel-
>>>> depmod/System.map-
>>>> ${KERNEL_VERSION}
>>>> +	install -d ${PKGDESTWORK}/${KERNEL_PACKAGE_NAME}-depmod/
>>>> +	echo "${KERNEL_VERSION}" >
>>>> ${PKGDESTWORK}/${KERNEL_PACKAGE_NAME}-
>>>> depmod/${KERNEL_PACKAGE_NAME}-
>>>> abiversion
>>>> +	cp ${B}/System.map
>>>> ${PKGDESTWORK}/${KERNEL_PACKAGE_NAME}-
>>>> depmod/System.map-${KERNEL_VERSION}
>>>>    }
>>>>    
>>>>    PACKAGEFUNCS += "emit_depmod_pkgdata"
>>>> @@ -388,7 +403,7 @@ do_shared_workdir () {
>>>>    	# Store the kernel version in sysroots for module-
>>>> base.bbclass
>>>>    	#
>>>>    
>>>> -	echo "${KERNEL_VERSION}" > $kerneldir/kernel-abiversion
>>>> +	echo "${KERNEL_VERSION}" >
>>>> $kerneldir/${KERNEL_PACKAGE_NAME}-abiversion
>>>>    
>>>>    	# Copy files required for module builds
>>>>    	cp System.map $kerneldir/System.map-${KERNEL_VERSION}
>>>> @@ -486,28 +501,28 @@ EXPORT_FUNCTIONS do_compile do_install
>>>> do_configure
>>>>    
>>>>    # kernel-base becomes kernel-${KERNEL_VERSION}
>>>>    # kernel-image becomes kernel-image-${KERNEL_VERSION}
>>>> -PACKAGES = "kernel kernel-base kernel-vmlinux kernel-image
>>>> kernel-
>>>> dev kernel-modules"
>>>> +PACKAGES = "${KERNEL_PACKAGE_NAME} ${KERNEL_PACKAGE_NAME}-base
>>>> ${KERNEL_PACKAGE_NAME}-vmlinux ${KERNEL_PACKAGE_NAME}-image
>>>> ${KERNEL_PACKAGE_NAME}-dev ${KERNEL_PACKAGE_NAME}-modules"
>>>>    FILES_${PN} = ""
>>>> -FILES_kernel-base =
>>>> "${nonarch_base_libdir}/modules/${KERNEL_VERSION}/modules.order
>>>> ${nonarch_base_libdir}/modules/${KERNEL_VERSION}/modules.builtin"
>>>> -FILES_kernel-image = ""
>>>> -FILES_kernel-dev = "/boot/System.map* /boot/Module.symvers*
>>>> /boot/config* ${KERNEL_SRC_PATH}
>>>> ${nonarch_base_libdir}/modules/${KERNEL_VERSION}/build"
>>>> -FILES_kernel-vmlinux = "/boot/vmlinux-${KERNEL_VERSION_NAME}"
>>>> -FILES_kernel-modules = ""
>>>> -RDEPENDS_kernel = "kernel-base"
>>>> +FILES_${KERNEL_PACKAGE_NAME}-base =
>>>> "${nonarch_base_libdir}/modules/${KERNEL_VERSION}/modules.order
>>>> ${nonarch_base_libdir}/modules/${KERNEL_VERSION}/modules.builtin"
>>>> +FILES_${KERNEL_PACKAGE_NAME}-image = ""
>>>> +FILES_${KERNEL_PACKAGE_NAME}-dev = "/boot/System.map*
>>>> /boot/Module.symvers* /boot/config* ${KERNEL_SRC_PATH}
>>>> ${nonarch_base_libdir}/modules/${KERNEL_VERSION}/build"
>>>> +FILES_${KERNEL_PACKAGE_NAME}-vmlinux = "/boot/vmlinux-
>>>> ${KERNEL_VERSION_NAME}"
>>>> +FILES_${KERNEL_PACKAGE_NAME}-modules = ""
>>>> +RDEPENDS_${KERNEL_PACKAGE_NAME} = "${KERNEL_PACKAGE_NAME}-base"
>>>>    # Allow machines to override this dependency if kernel image
>>>> files
>>>> are
>>>>    # not wanted in images as standard
>>>> -RDEPENDS_kernel-base ?= "kernel-image"
>>>> -PKG_kernel-image = "kernel-image-${@legitimize_package_name('${K
>>>> ERNE
>>>> L_VERSION}')}"
>>>> -RDEPENDS_kernel-image += "${@base_conditional('KERNEL_IMAGETYPE'
>>>> ,
>>>> 'vmlinux', 'kernel-vmlinux', '', d)}"
>>>> -PKG_kernel-base = "kernel-${@legitimize_package_name('${KERNEL_V
>>>> ERSI
>>>> ON}')}"
>>>> -RPROVIDES_kernel-base += "kernel-${KERNEL_VERSION}"
>>>> -ALLOW_EMPTY_kernel = "1"
>>>> -ALLOW_EMPTY_kernel-base = "1"
>>>> -ALLOW_EMPTY_kernel-image = "1"
>>>> -ALLOW_EMPTY_kernel-modules = "1"
>>>> -DESCRIPTION_kernel-modules = "Kernel modules meta package"
>>>> -
>>>> -pkg_postinst_kernel-base () {
>>>> +RDEPENDS_${KERNEL_PACKAGE_NAME}-base ?= "${KERNEL_PACKAGE_NAME}-
>>>> image"
>>>> +PKG_${KERNEL_PACKAGE_NAME}-image = "${KERNEL_PACKAGE_NAME}-
>>>> image-${@
>>>> legitimize_package_name('${KERNEL_VERSION}')}"
>>>> +RDEPENDS_${KERNEL_PACKAGE_NAME}-image += "${@base_conditional('K
>>>> ERNE
>>>> L_IMAGETYPE', 'vmlinux', '${KERNEL_PACKAGE_NAME}-vmlinux', '',
>>>> d)}"
>>>> +PKG_${KERNEL_PACKAGE_NAME}-base = "${KERNEL_PACKAGE_NAME}-${@leg
>>>> itim
>>>> ize_package_name('${KERNEL_VERSION}')}"
>>>> +RPROVIDES_${KERNEL_PACKAGE_NAME}-base +=
>>>> "${KERNEL_PACKAGE_NAME}-
>>>> ${KERNEL_VERSION}"
>>>> +ALLOW_EMPTY_${KERNEL_PACKAGE_NAME} = "1"
>>>> +ALLOW_EMPTY_${KERNEL_PACKAGE_NAME}-base = "1"
>>>> +ALLOW_EMPTY_${KERNEL_PACKAGE_NAME}-image = "1"
>>>> +ALLOW_EMPTY_${KERNEL_PACKAGE_NAME}-modules = "1"
>>>> +DESCRIPTION_${KERNEL_PACKAGE_NAME}-modules = "Kernel modules
>>>> meta
>>>> package"
>>>> +
>>>> +pkg_postinst_${KERNEL_PACKAGE_NAME}-base () {
>>>>    	if [ ! -e "$D/lib/modules/${KERNEL_VERSION}" ]; then
>>>>    		mkdir -p $D/lib/modules/${KERNEL_VERSION}
>>>>    	fi
>>>> @@ -521,7 +536,7 @@ pkg_postinst_kernel-base () {
>>>>    PACKAGESPLITFUNCS_prepend = "split_kernel_packages "
>>>>    
>>>>    python split_kernel_packages () {
>>>> -    do_split_packages(d, root='${nonarch_base_libdir}/firmware',
>>>> file_regex='^(.*)\.(bin|fw|cis|csp|dsp)$',
>>>> output_pattern='kernel-
>>>> firmware-%s', description='Firmware for %s', recursive=True,
>>>> extra_depends='')
>>>> +    do_split_packages(d, root='${nonarch_base_libdir}/firmware',
>>>> file_regex='^(.*)\.(bin|fw|cis|csp|dsp)$',
>>>> output_pattern='${KERNEL_PACKAGE_NAME}-firmware-%s',
>>>> description='Firmware for %s', recursive=True, extra_depends='')
>>>>    }
>>>>    
>>>>    # Many scripts want to look in arch/$arch/boot for the bootable
>>>> diff --git a/meta/conf/documentation.conf
>>>> b/meta/conf/documentation.conf
>>>> index 35b9103b4a..e061b98de3 100644
>>>> --- a/meta/conf/documentation.conf
>>>> +++ b/meta/conf/documentation.conf
>>>> @@ -248,6 +248,7 @@ KERNEL_IMAGETYPE[doc] = "The type of kernel
>>>> to
>>>> build for a device, usually set b
>>>>    KERNEL_IMAGETYPES[doc] = "The list of types of kernel to build
>>>> for a
>>>> device, usually set by the machine configuration files and
>>>> defaults
>>>> to KERNEL_IMAGETYPE."
>>>>    KERNEL_MODULE_AUTOLOAD[doc] = "Lists kernel modules that need
>>>> to be
>>>> auto-loaded during boot"
>>>>    KERNEL_MODULE_PROBECONF[doc] = "Lists kernel modules for which
>>>> the
>>>> build system expects to find module_conf_* values that specify
>>>> configuration for each of the modules"
>>>> +KERNEL_PACKAGE_NAME[doc] = "Name prefix for kernel packages.
>>>> Defaults to 'kernel'."
>>>>    KERNEL_PATH[doc] = "The location of the kernel sources. This
>>>> variable is set to the value of the STAGING_KERNEL_DIR within the
>>>> module class (module.bbclass)."
>>>>    KERNEL_SRC[doc] = "The location of the kernel sources. This
>>>> variable
>>>> is set to the value of the STAGING_KERNEL_DIR within the module
>>>> class
>>>> (module.bbclass)."
>>>>    KFEATURE_DESCRIPTION[doc] = "Provides a short description of a
>>>> configuration fragment. You use this variable in the .scc file
>>>> that
>>>> describes a configuration fragment file."
>>>> diff --git a/meta/recipes-kernel/linux/linux-dtb.inc
>>>> b/meta/recipes-
>>>> kernel/linux/linux-dtb.inc
>>>> index 0174c80d85..da6467bf9f 100644
>>>> --- a/meta/recipes-kernel/linux/linux-dtb.inc
>>>> +++ b/meta/recipes-kernel/linux/linux-dtb.inc
>>>> @@ -4,7 +4,7 @@ FILES_kernel-devicetree =
>>>> "/${KERNEL_IMAGEDEST}/devicetree*"
>>>>    PACKAGE_WRITE_DEPS += "virtual/update-alternatives-native"
>>>>    
>>>>    python __anonymous () {
>>>> -    d.appendVar("PACKAGES", " kernel-devicetree")
>>>> +    d.appendVar("PACKAGES", " ${KERNEL_PACKAGE_NAME}-
>>>> devicetree")
>>>>    }
>>>>    
>>>>    normalize_dtb () {
>>>> diff --git a/meta/recipes-kernel/linux/linux-yocto.inc
>>>> b/meta/recipes-kernel/linux/linux-yocto.inc
>>>> index 637506a2a8..4e0ce029da 100644
>>>> --- a/meta/recipes-kernel/linux/linux-yocto.inc
>>>> +++ b/meta/recipes-kernel/linux/linux-yocto.inc
>>>> @@ -12,7 +12,7 @@ INC_PR = "r4"
>>>>    # PREFERRED_PROVIDER for virtual/kernel. This avoids network
>>>> access
>>>> required
>>>>    # by the use of AUTOREV SRCREVs, which are the default for this
>>>> recipe.
>>>>    python () {
>>>> -    if d.getVar("PREFERRED_PROVIDER_virtual/kernel") !=
>>>> d.getVar("PN"):
>>>> +    if d.getVar("KERNEL_PACKAGE_NAME", True) == "kernel" and
>>>> d.getVar("PREFERRED_PROVIDER_virtual/kernel", True) !=
>>>> d.getVar("PN",
>>>> True):
>>>>            d.delVar("BB_DONT_CACHE")
>>>>            raise bb.parse.SkipPackage("Set
>>>> PREFERRED_PROVIDER_virtual/kernel to %s to enable it" %
>>>> (d.getVar("PN")))
>>>>    }