Support unsigned kernels for SecureBoot

1. In SecureBoot grub2 allows to exit secure mode and boot unsigned kernel - making use of this feature in iso grub config.

livecd-tools-21.1.secureboot.unsigned.kernel.patch

@@ -0,0 +1,15 @@
+diff --git a/imgcreate/live.py b/imgcreate/live.py
+index e9eb2ac..f959f14 100644
+--- a/imgcreate/live.py
++++ b/imgcreate/live.py
+@@ -801,8 +801,8 @@ search --no-floppy --set=root -l '%(isolabel)s'
+         else:
+             args["rootlabel"] = "CDLABEL=%(fslabel)s" % args
+         return """menuentry '%(long)s' --class rosa --class gnu-linux --class gnu --class os {
+-	linuxefi /isolinux/vmlinuz%(index)s root=%(rootlabel)s %(liveargs)s %(extra)s
+-	initrdefi /isolinux/initrd%(index)s.img
++	linux /isolinux/vmlinuz%(index)s root=%(rootlabel)s %(liveargs)s %(extra)s
++	initrd /isolinux/initrd%(index)s.img
+ }
+ """ %args
+ 

livecd-tools.spec

@@ -28,6 +28,7 @@ Patch11: livecd-tools-21.1.drop.initramfs.patch
 Patch12: livecd-tools-21.1.efi.no.dm.luks.patch
 Patch13: livecd-tools-21.1.basic.graphics.mode.fixed.patch
 Patch14: livecd-tools-21.1.shim.efi.renamed.patch
+Patch15: livecd-tools-21.1.secureboot.unsigned.kernel.patch
 
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root
 Requires: python-imgcreate = %{epoch}:%{version}-%{release}
@@ -91,6 +92,7 @@ like live image or appliances.
 %patch12 -p1
 %patch13 -p1
 %patch14 -p1
+%patch15 -p1
 
 %build
 make