feat(image): install upstream kexec which now have support for UKIs

pkgs/rootfs/mkinitrd.sh

@@ -0,0 +1,23 @@
+set -ex -p pipefail
+echo "Building initram disk"
+mkdir -p $out/root
+pushd $out/root
+
+### copy rootfs
+cp -prP $rootfs/* .
+find . -type d -exec chmod 755 {} \;
+mkdir sysroot
+
+### create directories
+ln -sf ../usr/lib/systemd/systemd init
+
+### Create needed files
+echo patos > ./etc/hostname
+
+ln -sf /etc/os-release ./etc/initrd-release
+
+# gen initrd
+find . -print0 | cpio --null --owner=root:root -o --format=newc | xz -9 --check=crc32 > ../initrd.xz
+
+popd
+rm -rf $out/root