yocto-cfg-fragments: introduce native provider of configuration fragments

To allow the use of the yocto configuration fragments in scenarios where
a kernel inherits kernel-yocto or has a custom fragment implementation, but
doesn't directly include the yocto-kernel-cache in the kernel SRC_URI,
we introduce a native provider of the fragments.

This fragment provider is independent of a kernel tree and when added
as a dependency to a recipe, the fragments will be placed in:

  recipe-sysroot-native/kcfg/

These can then be referenced on the SRC_URI or in KERNEL_FEEATURES by
using '../recipe-sysroot-native/kcfg' as the relative path to the
.scc or .cfg file. In the future, this won't be required as kernel-yocto
will always check the native sysroot for fragments, and fragments will
always be referenced by relative path from the base of the kernel-cache.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

recipes-kernel/linux/yocto-cfg-fragments.bb

@@ -0,0 +1,37 @@
+HOMEPAGE = "https://git.yoctoproject.org/cgit/cgit.cgi/yocto-kernel-cache/"
+SUMMARY = "Kernel configuration fragments"
+DESCRIPTION = "Typically used as part of a kernel clone, this is the standalone \
+fragment repository. Making it available to other fragment management schemes \
+"
+SECTION = "devel"
+
+LICENSE = "MIT"
+LIC_FILES_CHKSUM = "file://COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420"
+
+do_configure[noexec] = "1"
+do_compile[noexec] = "1"
+INHIBIT_DEFAULT_DEPS = "1"
+
+LINUX_VERSION ?= "5.14"
+PV = "v${LINUX_VERSION}+git${SRCREV}"
+
+SRCREV = "25509cd5563356638e78d33ec7e5354225fbd3db"
+SRC_URI = "\
+        git://git.yoctoproject.org/yocto-kernel-cache;branch=yocto-${LINUX_VERSION} \
+        "
+
+S = "${WORKDIR}/git"
+
+do_install() {
+    install -d ${D}${base_prefix}/kcfg
+
+    # copy the configuration fragments over to the native deploy
+    cp -r ${S}/* ${D}${base_prefix}/kcfg
+    # scripts bring in a bash dependency we don't want
+    rm -rf ${D}${base_prefix}/kcfg/scripts
+}
+
+FILES:${PN} += "kcfg/"
+SYSROOT_DIRS += "${base_prefix}/kcfg"
+BBCLASSEXTEND = "native nativesdk"
+