kernel-grub.bbclass: add a method to install/update for bzImage

While installing a rpm to update kernel on a deployed target, it will update
the boot area and the boot menu with the kernel as the priority but allow
you to fall back to the original kernel as well.

- In kernel-image's preinstall scriptlet, it backs up original kernel to avoid
  probable confliction with the new one.
- In kernel-image's postinstall scriptlet, it modify grub's config file to
  updates the new kernel as the boot priority.

[YOCTO #4104]

(From OE-Core rev: 8d872e7712a62fa4313a1114a92907c29beffa2e)

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta/classes/kernel-grub.bbclass b/meta/classes/kernel-grub.bbclass
new file mode 100644 (file)
index 0000000..70564f0
--- /dev/null
+++ b/meta/classes/kernel-grub.bbclass
@@ -0,0 +1,90 @@
+#
+# While installing a rpm to update kernel on a deployed target, it will update
+# the boot area and the boot menu with the kernel as the priority but allow
+# you to fall back to the original kernel as well.
+#
+# - In kernel-image's preinstall scriptlet, it backs up original kernel to avoid
+#   probable confliction with the new one.
+#
+# - In kernel-image's postinstall scriptlet, it modifies grub's config file to
+#   updates the new kernel as the boot priority.
+#
+
+pkg_preinst_kernel-image_append () {
+       # Parsing confliction
+       [ -f "$D/boot/grub/menu.list" ] && grubcfg="$D/boot/grub/menu.list"
+       [ -f "$D/boot/grub/grub.cfg" ] && grubcfg="$D/boot/grub/grub.cfg"
+       if [ -n "$grubcfg" ]; then
+               # Dereference symlink to avoid confliction with new kernel name.
+               if grep -q "/${KERNEL_IMAGETYPE} \+root=" $grubcfg; then
+                       if [ -L "$D/boot/${KERNEL_IMAGETYPE}" ]; then
+                               kimage=`realpath $D/boot/${KERNEL_IMAGETYPE} 2>/dev/null`
+                               if [ -f "$D$kimage" ]; then
+                                       sed -i "s:${KERNEL_IMAGETYPE} \+root=:${kimage##*/} root=:" $grubcfg
+                               fi
+                       fi
+               fi
+
+               # Rename old kernel if it conflicts with new kernel name.
+               if grep -q "/${KERNEL_IMAGETYPE}-${KERNEL_VERSION} \+root=" $grubcfg; then
+                       if [ -f "$D/boot/${KERNEL_IMAGETYPE}-${KERNEL_VERSION}" ]; then
+                               timestamp=`date +%s`
+                               kimage="$D/boot/${KERNEL_IMAGETYPE}-${KERNEL_VERSION}-$timestamp-back"
+                               sed -i "s:${KERNEL_IMAGETYPE}-${KERNEL_VERSION} \+root=:${kimage##*/} root=:" $grubcfg
+                               mv "$D/boot/${KERNEL_IMAGETYPE}-${KERNEL_VERSION}" "$kimage"
+                       fi
+               fi
+       fi
+}
+
+pkg_postinst_kernel-image_prepend () {
+       get_new_grub_cfg() {
+               grubcfg="$1"
+               title="Update ${KERNEL_IMAGETYPE}-${KERNEL_VERSION}-${PV}"
+               if [ "${grubcfg##*/}" = "grub.cfg" ]; then
+                       rootfs=`grep " *linux \+[^ ]\+ \+root=" $grubcfg -m 1 | \
+                                sed "s# *linux \+[^ ]\+ \+root=#    linux /${KERNEL_IMAGETYPE}-${KERNEL_VERSION} root=#"`
+
+                       echo "menuentry \"$title\" {"
+                       echo "    set root=(hd0,1)"
+                       echo "$rootfs"
+                       echo "}"
+               elif [ "${grubcfg##*/}" = "menu.list" ]; then
+                       rootfs=`grep "kernel \+[^ ]\+ \+root=" $grubcfg -m 1 | \
+                                sed "s#kernel \+[^ ]\+ \+root=#kernel /${KERNEL_IMAGETYPE}-${KERNEL_VERSION} root=#"`
+
+                       echo "default 0"
+                       echo "timeout 30"
+                       echo "title $title"
+                       echo "root  (hd0,0)"
+                       echo "$rootfs"
+               fi
+       }
+
+       get_old_grub_cfg() {
+               grubcfg="$1"
+               if [ "${grubcfg##*/}" = "grub.cfg" ]; then
+                       cat "$grubcfg"
+               elif [ "${grubcfg##*/}" = "menu.list" ]; then
+                       cat "$grubcfg" | sed -e '/^default/d' -e '/^timeout/d'
+               fi
+       }
+
+       if [ -f "$D/boot/grub/grub.cfg" ]; then
+               grubcfg="$D/boot/grub/grub.cfg"
+               old_image=`grep ' *linux \+[^ ]\+ \+root=' -m 1 "$grubcfg" | awk '{print $2}'`
+       elif [ -f "$D/boot/grub/menu.list" ]; then
+               grubcfg="$D/boot/grub/menu.list"
+               old_image=`grep '^kernel \+[^ ]\+ \+root=' -m 1 "$grubcfg" | awk '{print $2}'`
+       fi
+
+       # Don't update grubcfg at first install while old bzImage doesn't exist.
+       if [ -f "$D/boot/$old_image" ]; then
+               grubcfgtmp="$grubcfg.tmp"
+               get_new_grub_cfg "$grubcfg"  > $grubcfgtmp
+               get_old_grub_cfg "$grubcfg" >> $grubcfgtmp
+               mv $grubcfgtmp $grubcfg
+               echo "Caution! Update kernel may affect kernel-module!"
+       fi
+}
+