rebuild initrd as necessary before qemu

1 files changed, 17 insertions, 3 deletions

diff --git a/initrd.sh b/initrd.sh
index 5e7ed90..675dcc8 100755
--- a/initrd.sh
+++ b/initrd.sh
@@ -1,4 +1,18 @@
 #!/bin/sh
-set -ex
-cp -f /boot/vmlinuz-$(uname -r) isolinux/live/vmlinuz
-/usr/sbin/mkinitramfs -d initramfs-tools -o isolinux/live/initrd.img $(uname -r)
+
+initrd=isolinux/live/initrd.img
+vmlinuz=isolinux/live/vmlinuz
+
+conf_dir=initramfs-tools
+
+if [ ! -e "$initrd" -o ! -e "$vmlinuz" ]; then
+    need_update=1
+elif [ "$(find "$conf_dir" -newer "$initrd" -print -quit)" ]; then
+    need_update=1
+fi
+
+if [ "$need_update" ]; then
+    set -ex
+    cp -f /boot/vmlinuz-$(uname -r) "$vmlinuz"
+    /usr/sbin/mkinitramfs -d "$conf_dir" -o "$initrd" $(uname -r)
+fi