yocto-kernel: factor common routes, update to 2.6.37 and branch renaming

In order to extend and create more kernel recipes based on the
supported yocto kernel common routines need to be placed in
re-usable blocks.

To accomplish this meta/recipes-kernel/linux/linux-yocto_git.bb
is broken into three parts:

 - meta/classes/kernel-yocto.bbclass: contains common routines
   for checking out and configuring a yocto kernel git repository.
   This should be inherited by recipes that need this functionality.

 - meta/recipes-kernel/linux/linux-yocto.inc: Contains the machine
   mappings, compatibility, build directives and common task
   definitions for a yocto kernel based recipe. This inherits
   kernel-yocto, and is the typical point of entry for other recipes.

 - meta/recipes-kernel/linux/linuux-tools.inc: tasks and function definitions
   for kernel recipes that want to build/export perf

It also updates the linux-yocto recipe to default to 2.6.37.

As part of the update to 2.6.37 the branch naming and conventions
have been modified to show inheritance, and be more generic.

For example:

  master
  meta
  yocto/base
  yocto/standard/arm_versatile_926ejs
  yocto/standard/base
  yocto/standard/beagleboard
  yocto/standard/common_pc/atom-pc
  yocto/standard/common_pc/base
  yocto/standard/common_pc_64
  yocto/standard/fsl-mpc8315e-rdb
  yocto/standard/intel_atom_z530
  yocto/standard/intel_core_qm57_pch
  yocto/standard/mti_malta32_be
  yocto/standard/preempt_rt/base
  yocto/standard/preempt_rt/common_pc
  yocto/standard/preempt_rt/common_pc_64
  yocto/standard/preempt_rt/intel_atom_z530
  yocto/standard/preempt_rt/intel_core_qm57_pch
  yocto/standard/qemu_ppc32
  yocto/standard/routerstationpro

In this structure:

  master: tracks the mainline kernel
  meta: meta information for the BSPs and kernel features
  yocto/base: baseline kernel branch
  yocto/standard/base: 'standard' kernel, contains features
                        and configs for all BSPs
  yocto/standard/<machine>: represents a BSP with specific
                            features or configurations

The tools, tree and libc-headers have all been updated to
deal with this new structure. Also in addition to dealing with
the new structure, they continue to work with the existing
tree and will adapt at runtime to the differences.

The linux-yocto-stable_git.bb recipe continues to build the
2.6.34 based tree,and linux-yocto_git.bb builds 2.6.37. As
boards are enabled for the new kernel they will move from
-stable to the development kernel. As of now, only the
emulated targets have moved to 2.6.37-rcX

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

1 files changed, 202 insertions, 0 deletions

diff --git a/meta/classes/kernel-yocto.bbclass b/meta/classes/kernel-yocto.bbclass
new file mode 100644
index 000000000..8e820122e
--- /dev/null
+++ b/meta/classes/kernel-yocto.bbclass
@@ -0,0 +1,202 @@
+S = "${WORKDIR}/linux"
+
+# Determine which branch to fetch and build. Not all branches are in the
+# upstream repo (but will be locally created after the fetchers run) so 
+# a fallback branch needs to be chosen. 
+#
+# The default machine 'UNDEFINED'. If the machine is not set to a specific
+# branch in this recipe or in a recipe extension, then we fallback to a 
+# branch that is always present 'standard'. This sets the KBRANCH variable
+# and is used in the SRC_URI. The machine is then set back to ${MACHINE},
+# since futher processing will use that to create local branches
+python __anonymous () {
+    import bb, re
+
+    version = bb.data.getVar("LINUX_VERSION", d, 1)
+    # 2.6.34 signifies the old-style tree, so we need some temporary
+    # conditional processing based on the kernel version.
+    if version == "2.6.34":
+        bb.data.setVar("KBRANCH", "${KMACHINE}-${LINUX_KERNEL_TYPE}", d)
+        bb.data.setVar("KMETA", "wrs_meta", d)
+        mach = bb.data.getVar("KMACHINE", d, 1)
+        if mach == "UNDEFINED":
+            bb.data.setVar("KBRANCH", "standard", d)
+            bb.data.setVar("KMACHINE", "${MACHINE}", d)
+            # track the global configuration on a bootstrapped BSP
+            bb.data.setVar("SRCREV_machine", "${SRCREV_meta}", d)
+            bb.data.setVar("BOOTSTRAP", "t", d)
+    else:
+        # The branch for a build is:
+        #    yocto/<kernel type>/${KMACHINE} or
+        #    yocto/<kernel type>/${KMACHINE}/base
+        bb.data.setVar("KBRANCH", bb.data.expand("yocto/${LINUX_KERNEL_TYPE}/${KMACHINE}",d), d)
+        bb.data.setVar("KMETA", "meta", d)
+
+        mach = bb.data.getVar("KMACHINE", d, 1)
+        # drop the "/base" if it was on the KMACHINE
+        kmachine = mach.replace('/base','')
+        # and then write KMACHINE back
+        bb.data.setVar('KMACHINE_' + bb.data.expand("${MACHINE}",d), kmachine, d)
+
+        if mach == "UNDEFINED":
+            bb.data.setVar("KBRANCH", "yocto/standard/base", d)
+            bb.data.setVar('KMACHINE_' + bb.data.expand("${MACHINE}",d), bb.data.expand("${MACHINE}",d), d)
+            bb.data.setVar("SRCREV_machine", "standard", d)
+            bb.data.setVar("BOOTSTRAP", "t", d)
+}
+
+do_patch() {
+	cd ${S}
+	if [ -f ${WORKDIR}/defconfig ]; then
+	    defconfig=${WORKDIR}/defconfig
+	fi
+
+	if [ -n "${BOOTSTRAP}" ]; then
+	    kbranch="yocto/${LINUX_KERNEL_TYPE}/${KMACHINE}"
+	else
+	    kbranch=${KBRANCH}
+	fi
+
+	# simply ensures that a branch of the right name has been created
+	createme ${ARCH} ${kbranch} ${defconfig}
+	if [ $? -ne 0 ]; then
+		echo "ERROR. Could not create ${kbranch}"
+		exit 1
+	fi
+
+	# updates or generates the target description
+	if [ -n "${KERNEL_FEATURES}" ]; then
+	       addon_features="--features ${KERNEL_FEATURES}"
+	fi
+	updateme ${addon_features} ${ARCH} ${WORKDIR}
+	if [ $? -ne 0 ]; then
+		echo "ERROR. Could not update ${kbranch}"
+		exit 1
+	fi
+
+	# executes and modifies the source tree as required
+	patchme ${kbranch}
+	if [ $? -ne 0 ]; then
+		echo "ERROR. Could not modify ${kbranch}"
+		exit 1
+	fi
+}
+
+do_kernel_checkout() {
+	if [ -d ${WORKDIR}/.git/refs/remotes/origin ]; then
+		echo "Fixing up git directory for ${LINUX_KERNEL_TYPE}/${KMACHINE}"
+		rm -rf ${S}
+		mkdir ${S}
+		mv ${WORKDIR}/.git ${S}
+	
+		if [ -e ${S}/.git/packed-refs ]; then
+			cd ${S}
+			rm -f .git/refs/remotes/origin/HEAD
+IFS='
+';
+			for r in `git show-ref | grep remotes`; do
+				ref=`echo $r | cut -d' ' -f1`; 
+				b=`echo $r | cut -d' ' -f2 | sed 's%refs/remotes/origin/%%'`;
+				dir=`dirname $b`
+				mkdir -p .git/refs/heads/$dir
+				echo $ref > .git/refs/heads/$b
+			done
+			cd ..
+		else
+			cp -r ${S}/.git/refs/remotes/origin/* ${S}/.git/refs/heads
+			rmdir ${S}/.git/refs/remotes/origin
+		fi
+	fi
+	cd ${S}
+
+	# checkout and clobber and unimportant files
+	git checkout -f ${KBRANCH}
+}
+do_kernel_checkout[dirs] = "${S}"
+
+addtask kernel_checkout before do_patch after do_unpack
+
+do_kernel_configme() {
+	echo "[INFO] doing kernel configme"
+
+	cd ${S}
+	configme --reconfig
+	if [ $? -ne 0 ]; then
+		echo "ERROR. Could not configure ${KMACHINE}-${LINUX_KERNEL_TYPE}"
+		exit 1
+	fi
+
+	echo "# Global settings from linux recipe" >> ${B}/.config
+	echo "CONFIG_LOCALVERSION="\"${LINUX_VERSION_EXTENSION}\" >> ${B}/.config
+}
+
+do_kernel_configcheck() {
+	echo "[INFO] validating kernel configuration"
+	cd ${B}/..
+	kconf_check ${B}/.config ${B} ${S} ${B} ${LINUX_VERSION} ${KMACHINE}-${LINUX_KERNEL_TYPE}
+}
+
+
+# Ensure that the branches (BSP and meta) are on the locatios specified by
+# their SRCREV values. If they are NOT on the right commits, the branches
+# are reset to the correct commit.
+do_validate_branches() {
+	cd ${S}
+ 	branch_head=`git show-ref -s --heads ${KBRANCH}`
+ 	meta_head=`git show-ref -s --heads ${KMETA}`
+ 	target_branch_head="${SRCREV_machine}"
+ 	target_meta_head="${SRCREV_meta}"
+
+	# nothing to do if bootstrapping
+ 	if [ -n "${BOOTSTRAP}" ]; then
+ 	 	return
+ 	fi
+
+	current=`git branch |grep \*|sed 's/^\* //'`
+	if [ -n "$target_branch_head" ] && [ "$branch_head" != "$target_branch_head" ]; then
+		if [ -n "${KERNEL_REVISION_CHECKING}" ]; then
+			git show ${target_branch_head} > /dev/null 2>&1
+			if [ $? -eq 0 ]; then
+				echo "Forcing branch $current to ${target_branch_head}"
+				git branch -m $current $current-orig
+				git checkout -b $current ${target_branch_head}
+			else
+				echo "ERROR ${target_branch_head} is not a valid commit ID."
+				echo "The kernel source tree may be out of sync"
+				exit 1
+			fi	       
+		fi
+	fi
+
+	if [ "$meta_head" != "$target_meta_head" ]; then
+		if [ -n "${KERNEL_REVISION_CHECKING}" ]; then
+			git show ${target_meta_head} > /dev/null 2>&1
+			if [ $? -eq 0 ]; then
+				echo "Forcing branch meta to ${target_meta_head}"
+				git branch -m ${KMETA} ${KMETA}-orig
+				git checkout -b ${KMETA} ${target_meta_head}
+			else
+				echo "ERROR ${target_meta_head} is not a valid commit ID"
+				echo "The kernel source tree may be out of sync"
+				exit 1
+			fi	   
+		fi
+	fi
+
+	# restore the branch for builds
+	git checkout -f ${KBRANCH}
+}
+
+# Many scripts want to look in arch/$arch/boot for the bootable
+# image. This poses a problem for vmlinux based booting. This 
+# task arranges to have vmlinux appear in the normalized directory
+# location.
+do_kernel_link_vmlinux() {
+	if [ ! -d "${B}/arch/${ARCH}/boot" ]; then
+		mkdir ${B}/arch/${ARCH}/boot
+	fi
+	cd ${B}/arch/${ARCH}/boot
+	ln -sf ../../../vmlinux
+}
+
+