Add custom isar-initramfs example

isar-initramfs is a custom initramfs which additionally has the
initramfs-example module installed.  It is also built as part of
the CI.

Signed-off-by: Harald Seiler <hws@denx.de>

meta-isar/recipes-initramfs/images/isar-initramfs.bb

@@ -0,0 +1,18 @@
+# Example of a custom initramfs image recipe.  The image will be deployed to
+#
+#   build/tmp/deploy/images/${MACHINE}/isar-initramfs-${DISTRO}-${MACHINE}.initrd.img
+#
+# This software is a part of ISAR.
+
+inherit initramfs
+
+# Debian packages that should be installed into the system for building the
+# initramfs.  E.g. the cryptsetup package which contains initramfs scripts for
+# decrypting a root filesystem.
+INITRAMFS_PREINSTALL += " \
+    "
+
+# Recipes that should be installed into the initramfs build rootfs.
+INITRAMFS_INSTALL += " \
+    initramfs-example \
+    "

scripts/ci_build.sh

@@ -28,6 +28,7 @@ TARGETS_SET="\
             mc:qemuamd64-stretch:isar-image-base \
             mc:qemuamd64-buster:isar-image-base \
             mc:qemuamd64-buster-tgz:isar-image-base \
+            mc:qemuamd64-buster:isar-initramfs \
             mc:qemumipsel-stretch:isar-image-base \
             mc:qemumipsel-buster:isar-image-base \
             mc:nand-ubi-demo-buster:isar-image-ubi \