kernel: Add support for multiple kernel packages

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. Add `KERNEL_PACKAGE_NAME_pn-linux-yocto-tiny = "tiny-linux"`
    to local.conf so that linux-yocto-tiny may build alongside
    the main kernel (linux-yocto).
 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. Add `CORE_IMAGE_BASE_INSTALL_append_pn-core-image-base = "tiny-linux"`
    to local.conf to install both kernel flavors in core-image-base.
 6. `bitbake core-image-base` to build an image.
 7. Verified image contains two bzImage's under /boot/, with
    "yocto-standard" (linux-yocto recipe) selected to boot via symlink.

Discussion threads:
http://lists.openembedded.org/pipermail/openembedded-core/2015-December/thread.html#114122
http://lists.openembedded.org/pipermail/openembedded-core/2017-July/thread.html#139130

[YOCTO #11363]

(From OE-Core rev: 6c8c899849d101fd1b86aad0b8eed05c7c785924)

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>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

10 files changed, 94 insertions, 62 deletions

diff --git a/meta/classes/kernel-devicetree.bbclass b/meta/classes/kernel-devicetree.bbclass
index 6e08be4b70..4f80cc62eb 100644
--- a/meta/classes/kernel-devicetree.bbclass
+++ b/meta/classes/kernel-devicetree.bbclass
@@ -1,10 +1,10 @@
 # Support for device tree generation
 PACKAGES_append = " \
-    kernel-devicetree \
-    ${@['kernel-image-zimage-bundle', ''][d.getVar('KERNEL_DEVICETREE_BUNDLE') != '1']} \
+    ${KERNEL_PACKAGE_NAME}-devicetree \
+    ${@[d.getVar('KERNEL_PACKAGE_NAME') + '-image-zimage-bundle', ''][d.getVar('KERNEL_DEVICETREE_BUNDLE') != '1']} \
 "
-FILES_kernel-devicetree = "/${KERNEL_IMAGEDEST}/*.dtb /${KERNEL_IMAGEDEST}/*.dtbo"
-FILES_kernel-image-zimage-bundle = "/${KERNEL_IMAGEDEST}/zImage-*.dtb.bin"
+FILES_${KERNEL_PACKAGE_NAME}-devicetree = "/${KERNEL_IMAGEDEST}/*.dtb /${KERNEL_IMAGEDEST}/*.dtbo"
+FILES_${KERNEL_PACKAGE_NAME}-image-zimage-bundle = "/${KERNEL_IMAGEDEST}/zImage-*.dtb.bin"
 
 # Generate kernel+devicetree bundle
 KERNEL_DEVICETREE_BUNDLE ?= "0"
diff --git a/meta/classes/kernel-module-split.bbclass b/meta/classes/kernel-module-split.bbclass
index 1035525dac..73c7f18c78 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 ?= "${@ d.getVar("KERNEL_PACKAGE_NAME", True) or "kernel" }-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) or "kernel"
+    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 e7eda83bd0..f7b612f84f 100644
--- a/meta/classes/kernel.bbclass
+++ b/meta/classes/kernel.bbclass
@@ -1,6 +1,9 @@
 inherit linux-kernel-base kernel-module-split
 
-PROVIDES += "virtual/kernel"
+KERNEL_PACKAGE_NAME ??= "kernel"
+KERNEL_DEPLOYSUBDIR ??= "${@ "" if (d.getVar("KERNEL_PACKAGE_NAME", True) == "kernel") else d.getVar("KERNEL_PACKAGE_NAME", True) }"
+
+PROVIDES += "${@ "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"
 
@@ -34,11 +37,32 @@ KERNEL_VERSION_PKG_NAME = "${@legitimize_package_name(d.getVar('KERNEL_VERSION')
 KERNEL_VERSION_PKG_NAME[vardepvalue] = "${LINUX_VERSION}"
 
 python __anonymous () {
+    pn = d.getVar("PN", True)
+    kpn = d.getVar("KERNEL_PACKAGE_NAME", True)
+
+    # XXX Remove this after bug 11905 is resolved
+    #  FILES_${KERNEL_PACKAGE_NAME}-dev doesn't expand correctly
+    if kpn == pn:
+        bb.warn("Some packages (E.g. *-dev) might be missing due to "
+                "bug 11905 (variable KERNEL_PACKAGE_NAME == PN)")
+
+    # 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 kpn != "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():
@@ -55,15 +79,15 @@ 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 + '-${KERNEL_VERSION_NAME}' + ' /' + imagedest + '/' + type)
+        d.setVar('FILES_' + kname + '-image-' + typelower, '/' + imagedest + '/' + type + '-${KERNEL_VERSION_NAME}' + ' /' + imagedest + '/' + type)
 
-        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')
 
     image = d.getVar('INITRAMFS_IMAGE')
     if image:
@@ -121,9 +145,9 @@ 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}"
@@ -339,7 +363,9 @@ kernel_do_install() {
         install -d ${D}/boot
         for type in ${KERNEL_IMAGETYPES} ; do
                 install -m 0644 ${KERNEL_OUTPUT_DIR}/${type} ${D}/${KERNEL_IMAGEDEST}/${type}-${KERNEL_VERSION}
-                ln -sf ${type}-${KERNEL_VERSION} ${D}/${KERNEL_IMAGEDEST}/${type}
+                if [ "${KERNEL_PACKAGE_NAME}" == "kernel" ]; then
+                        ln -sf ${type}-${KERNEL_VERSION} ${D}/${KERNEL_IMAGEDEST}/${type}
+                fi
         done
         install -m 0644 System.map ${D}/boot/System.map-${KERNEL_VERSION}
         install -m 0644 .config ${D}/boot/config-${KERNEL_VERSION}
@@ -393,9 +419,9 @@ 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"
@@ -411,7 +437,7 @@ 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}
@@ -509,28 +535,28 @@ 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('${KERNEL_VERSION}')}"
-RDEPENDS_kernel-image += "${@base_conditional('KERNEL_IMAGETYPE', 'vmlinux', 'kernel-vmlinux', '', d)}"
-PKG_kernel-base = "kernel-${@legitimize_package_name('${KERNEL_VERSION}')}"
-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 += "${@base_conditional('KERNEL_IMAGETYPE', 'vmlinux', '${KERNEL_PACKAGE_NAME}-vmlinux', '', d)}"
+PKG_${KERNEL_PACKAGE_NAME}-base = "${KERNEL_PACKAGE_NAME}-${@legitimize_package_name('${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
@@ -544,7 +570,7 @@ 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/$arch/boot for the bootable
@@ -635,21 +661,27 @@ MODULE_TARBALL_SYMLINK_NAME ?= "modules-${MACHINE}.tgz"
 MODULE_TARBALL_DEPLOY ?= "1"
 
 kernel_do_deploy() {
+        deployDir="${DEPLOYDIR}"
+        if [ -n "${KERNEL_DEPLOYSUBDIR}" ]; then
+                deployDir="${DEPLOYDIR}/${KERNEL_DEPLOYSUBDIR}"
+                mkdir "$deployDir"
+        fi
+
         for type in ${KERNEL_IMAGETYPES} ; do
                 base_name=${type}-${KERNEL_IMAGE_BASE_NAME}
-                install -m 0644 ${KERNEL_OUTPUT_DIR}/${type} ${DEPLOYDIR}/${base_name}.bin
+                install -m 0644 ${KERNEL_OUTPUT_DIR}/${type} $deployDir/${base_name}.bin
         done
         if [ ${MODULE_TARBALL_DEPLOY} = "1" ] && (grep -q -i -e '^CONFIG_MODULES=y$' .config); then
                 mkdir -p ${D}/lib
-                tar -cvzf ${DEPLOYDIR}/${MODULE_TARBALL_BASE_NAME} -C ${D} lib
-                ln -sf ${MODULE_TARBALL_BASE_NAME} ${DEPLOYDIR}/${MODULE_TARBALL_SYMLINK_NAME}
+                tar -cvzf $deployDir/${MODULE_TARBALL_BASE_NAME} -C ${D} lib
+                ln -sf ${MODULE_TARBALL_BASE_NAME} $deployDir/${MODULE_TARBALL_SYMLINK_NAME}
         fi
 
         for type in ${KERNEL_IMAGETYPES} ; do
                 base_name=${type}-${KERNEL_IMAGE_BASE_NAME}
                 symlink_name=${type}-${KERNEL_IMAGE_SYMLINK_NAME}
-                ln -sf ${base_name}.bin ${DEPLOYDIR}/${symlink_name}.bin
-                ln -sf ${base_name}.bin ${DEPLOYDIR}/${type}
+                ln -sf ${base_name}.bin $deployDir/${symlink_name}.bin
+                ln -sf ${base_name}.bin $deployDir/${type}
         done
 
         cd ${B}
@@ -659,8 +691,8 @@ kernel_do_deploy() {
                         echo "Copying deploy ${type} kernel-initramfs image and setting up links..."
                         initramfs_base_name=${type}-${INITRAMFS_BASE_NAME}
                         initramfs_symlink_name=${type}-initramfs-${MACHINE}
-                        install -m 0644 ${KERNEL_OUTPUT_DIR}/${type}.initramfs ${DEPLOYDIR}/${initramfs_base_name}.bin
-                        ln -sf ${initramfs_base_name}.bin ${DEPLOYDIR}/${initramfs_symlink_name}.bin
+                        install -m 0644 ${KERNEL_OUTPUT_DIR}/${type}.initramfs $deployDir/${initramfs_base_name}.bin
+                        ln -sf ${initramfs_base_name}.bin $deployDir/${initramfs_symlink_name}.bin
                 fi
         done
 }
diff --git a/meta/conf/documentation.conf b/meta/conf/documentation.conf
index 081e726d4b..995b60e158 100644
--- a/meta/conf/documentation.conf
+++ b/meta/conf/documentation.conf
@@ -247,6 +247,7 @@ 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/kmod/depmodwrapper-cross_1.0.bb b/meta/recipes-kernel/kmod/depmodwrapper-cross_1.0.bb
index 68d3f84c0b..48f012918a 100644
--- a/meta/recipes-kernel/kmod/depmodwrapper-cross_1.0.bb
+++ b/meta/recipes-kernel/kmod/depmodwrapper-cross_1.0.bb
@@ -23,17 +23,13 @@ if [ "\$1" != "-a" -o "\$2" != "-b" ]; then
     echo "Usage: depmodwrapper -a -b rootfs KERNEL_VERSION" >&2
     exit 1
 fi
-if [ ! -r ${PKGDATA_DIR}/kernel-depmod/kernel-abiversion ]; then
-    echo "Unable to read: ${PKGDATA_DIR}/kernel-depmod/kernel-abiversion" >&2
-else
-    kernelabi=\$(cat ${PKGDATA_DIR}/kernel-depmod/kernel-abiversion)
-    if [ "\$kernelabi" != "\$4" ]; then
-        echo "Error: Kernel version \$4 does not match kernel-abiversion (\$kernelabi)" >&2
-        exit 1
-    fi
+
+kernelabi=""
+if [ -r "${PKGDATA_DIR}/kernel-depmod/kernel-abiversion" ]; then
+    kernelabi=\$(cat "${PKGDATA_DIR}/kernel-depmod/kernel-abiversion")
 fi
 
-if [ ! -r ${PKGDATA_DIR}/kernel-depmod/System.map-\$4 ]; then
+if [ ! -r ${PKGDATA_DIR}/kernel-depmod/System.map-\$4 ] || [ "\$kernelabi" != "\$4" ]; then
     echo "Unable to read: ${PKGDATA_DIR}/kernel-depmod/System.map-\$4" >&2
     exec env depmod "\$1" "\$2" "\$3" "\$4"
 else
diff --git a/meta/recipes-kernel/linux/linux-yocto-rt_4.10.bb b/meta/recipes-kernel/linux/linux-yocto-rt_4.10.bb
index fd31bf986c..40d6e4ac23 100644
--- a/meta/recipes-kernel/linux/linux-yocto-rt_4.10.bb
+++ b/meta/recipes-kernel/linux/linux-yocto-rt_4.10.bb
@@ -7,7 +7,7 @@ require recipes-kernel/linux/linux-yocto.inc
 # to build multiple virtual/kernel providers, e.g. as dependency of
 # core-image-rt-sdk, core-image-rt.
 python () {
-    if d.getVar("PREFERRED_PROVIDER_virtual/kernel") != "linux-yocto-rt":
+    if d.getVar("KERNEL_PACKAGE_NAME", True) == "kernel" and d.getVar("PREFERRED_PROVIDER_virtual/kernel") != "linux-yocto-rt":
         raise bb.parse.SkipPackage("Set PREFERRED_PROVIDER_virtual/kernel to linux-yocto-rt to enable it")
 }
 
diff --git a/meta/recipes-kernel/linux/linux-yocto-rt_4.12.bb b/meta/recipes-kernel/linux/linux-yocto-rt_4.12.bb
index 25f3963c74..ed65f77a91 100644
--- a/meta/recipes-kernel/linux/linux-yocto-rt_4.12.bb
+++ b/meta/recipes-kernel/linux/linux-yocto-rt_4.12.bb
@@ -7,7 +7,7 @@ require recipes-kernel/linux/linux-yocto.inc
 # to build multiple virtual/kernel providers, e.g. as dependency of
 # core-image-rt-sdk, core-image-rt.
 python () {
-    if d.getVar("PREFERRED_PROVIDER_virtual/kernel") != "linux-yocto-rt":
+    if d.getVar("KERNEL_PACKAGE_NAME", True) == "kernel" and d.getVar("PREFERRED_PROVIDER_virtual/kernel") != "linux-yocto-rt":
         raise bb.parse.SkipPackage("Set PREFERRED_PROVIDER_virtual/kernel to linux-yocto-rt to enable it")
 }
 
diff --git a/meta/recipes-kernel/linux/linux-yocto-rt_4.4.bb b/meta/recipes-kernel/linux/linux-yocto-rt_4.4.bb
index c1cbf35a25..e1547e9960 100644
--- a/meta/recipes-kernel/linux/linux-yocto-rt_4.4.bb
+++ b/meta/recipes-kernel/linux/linux-yocto-rt_4.4.bb
@@ -7,7 +7,7 @@ require recipes-kernel/linux/linux-yocto.inc
 # to build multiple virtual/kernel providers, e.g. as dependency of
 # core-image-rt-sdk, core-image-rt.
 python () {
-    if d.getVar("PREFERRED_PROVIDER_virtual/kernel") != "linux-yocto-rt":
+    if d.getVar("KERNEL_PACKAGE_NAME", True) == "kernel" and d.getVar("PREFERRED_PROVIDER_virtual/kernel") != "linux-yocto-rt":
         raise bb.parse.SkipPackage("Set PREFERRED_PROVIDER_virtual/kernel to linux-yocto-rt to enable it")
 }
 
diff --git a/meta/recipes-kernel/linux/linux-yocto-rt_4.9.bb b/meta/recipes-kernel/linux/linux-yocto-rt_4.9.bb
index d225339c14..fa25629861 100644
--- a/meta/recipes-kernel/linux/linux-yocto-rt_4.9.bb
+++ b/meta/recipes-kernel/linux/linux-yocto-rt_4.9.bb
@@ -7,7 +7,7 @@ require recipes-kernel/linux/linux-yocto.inc
 # to build multiple virtual/kernel providers, e.g. as dependency of
 # core-image-rt-sdk, core-image-rt.
 python () {
-    if d.getVar("PREFERRED_PROVIDER_virtual/kernel") != "linux-yocto-rt":
+    if d.getVar("KERNEL_PACKAGE_NAME", True) == "kernel" and d.getVar("PREFERRED_PROVIDER_virtual/kernel") != "linux-yocto-rt":
         raise bb.parse.SkipPackage("Set PREFERRED_PROVIDER_virtual/kernel to linux-yocto-rt to enable it")
 }
 
diff --git a/meta/recipes-kernel/linux/linux-yocto.inc b/meta/recipes-kernel/linux/linux-yocto.inc
index 9c1f61be75..8a70eb5018 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")))
 }