INITRD var: make it a list of filesystem images

The initrd image used by the Linux kernel is list of file system images
concatenated together and presented as a single initrd file at boot time.

So far the initrd is a single filesystem image. But in cases like to support
early microcode loading, the initrd image need to have multiple filesystem
images concatenated together.

This commit is extending the INITRD variable from a single filesystem image
to a list of filesystem images to satisfy the need mentioned above.

(From OE-Core rev: b0ac481dda99d8f4be8015964fcb2cb01afce08c)

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 22 insertions, 5 deletions

diff --git a/meta/classes/bootimg.bbclass b/meta/classes/bootimg.bbclass
index d52aacea81..7b3ce65910 100644
--- a/meta/classes/bootimg.bbclass
+++ b/meta/classes/bootimg.bbclass
@@ -18,7 +18,7 @@
 # an hdd)
 
 # External variables (also used by syslinux.bbclass)
-# ${INITRD} - indicates a filesystem image to use as an initrd (optional)
+# ${INITRD} - indicates a list of filesystem images to concatenate and use as an initrd (optional)
 # ${COMPRESSISO} - Transparent compress ISO, reduce size ~40% if set to 1
 # ${NOISO}  - skip building the ISO image if set to 1
 # ${NOHDD}  - skip building the HDD image if set to 1
@@ -67,9 +67,17 @@ populate() {
 
         # Install bzImage, initrd, and rootfs.img in DEST for all loaders to use.
         install -m 0644 ${STAGING_KERNEL_DIR}/bzImage ${DEST}/vmlinuz
-
-        if [ -n "${INITRD}" ] && [ -s "${INITRD}" ]; then
-                install -m 0644 ${INITRD} ${DEST}/initrd
+        
+        # initrd is made of concatenation of multiple filesystem images
+        if [ -n "${INITRD}" ]; then
+                rm -f ${DEST}/initrd
+                for fs in ${INITRD}
+                do
+                        if [ -s "${fs}" ]; then
+                                cat ${fs} >> ${DEST}/initrd
+                        fi
+                done
+                chmod 0644 ${DEST}/initrd
         fi
 
         if [ -n "${ROOTFS}" ] && [ -s "${ROOTFS}" ]; then
@@ -80,10 +88,19 @@ populate() {
 
 build_iso() {
         # Only create an ISO if we have an INITRD and NOISO was not set
-        if [ -z "${INITRD}" ] || [ ! -s "${INITRD}" ] || [ "${NOISO}" = "1" ]; then
+        if [ -z "${INITRD}" ] || [ "${NOISO}" = "1" ]; then
                 bbnote "ISO image will not be created."
                 return
         fi
+        # ${INITRD} is a list of multiple filesystem images
+        for fs in ${INITRD}
+        do
+                if [ ! -s "${fs}" ]; then
+                        bbnote "ISO image will not be created. ${fs} is invalid."
+                        return
+                fi
+        done
+
 
         populate ${ISODIR}