[PATCH V2 2/2] kernel.bbclass: handles symbolic KERNEL_OUTPUT in bundle_initramfs task

[Ming Liu <ming.liu@windriver.com>]

In many cases, KERNEL_OUTPUT is a symbolic link to the real bootable image,
but in bundle_initramfs task, it's not considered so that the KERNEL_OUTPUT
is being renamed/restored as a regular file, this leads it finally point to
a incorrect target, or even worse, break the bundle_initramfs task for
KERNEL_OUTPUT is not going to be regenerated in case it is a symbolic link
to vmlinux.

Signed-off-by: Ming Liu <ming.liu@windriver.com>
---
 meta/classes/kernel.bbclass | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/meta/classes/kernel.bbclass b/meta/classes/kernel.bbclass
index 966066f..ce987a5 100644
--- a/meta/classes/kernel.bbclass
+++ b/meta/classes/kernel.bbclass
@@ -123,13 +123,28 @@ do_bundle_initramfs () {
 	if [ ! -z "${INITRAMFS_IMAGE}" -a x"${INITRAMFS_IMAGE_BUNDLE}" = x1 ]; then
 		echo "Creating a kernel image with a bundled initramfs..."
 		copy_initramfs
-		if [ -e ${KERNEL_OUTPUT} ] ; then
+		# Backuping kernel image relies on its type(regular file or symbolic link)
+		linkpath=""
+		realpath=""
+		if [ -h ${KERNEL_OUTPUT} ] ; then
+			linkpath=`readlink -n ${KERNEL_OUTPUT}`
+			realpath=`readlink -fn ${KERNEL_OUTPUT}`
+			mv -f $realpath $realpath.bak
+		elif [ -f ${KERNEL_OUTPUT} ]; then
 			mv -f ${KERNEL_OUTPUT} ${KERNEL_OUTPUT}.bak
 		fi
 		use_alternate_initrd=CONFIG_INITRAMFS_SOURCE=${B}/usr/${INITRAMFS_IMAGE}-${MACHINE}.cpio
 		kernel_do_compile
-		mv -f ${KERNEL_OUTPUT} ${KERNEL_OUTPUT}.initramfs
-		mv -f ${KERNEL_OUTPUT}.bak ${KERNEL_OUTPUT}
+		# Restoring kernel image
+		if [ -n $realpath ]; then
+			mv -f $realpath $realpath.initramfs
+			mv -f $realpath.bak $realpath
+			cd ${B}/$(dirname ${KERNEL_OUTPUT})
+			ln -sf $linkpath.initramfs
+		else
+			mv -f ${KERNEL_OUTPUT} ${KERNEL_OUTPUT}.initramfs
+			mv -f ${KERNEL_OUTPUT}.bak ${KERNEL_OUTPUT}
+		fi
 		# Update install area
 		echo "There is kernel image bundled with initramfs: ${B}/${KERNEL_OUTPUT}.initramfs"
 		install -m 0644 ${B}/${KERNEL_OUTPUT}.initramfs ${D}/boot/${KERNEL_IMAGETYPE}-initramfs-${MACHINE}.bin
-- 
1.8.4.1