boot/efi: Optionally sign our EFI bootloader

* The private keys are in possession of Haiku, Inc.

Change-Id: I3b5b004e1dce0102f8a65f6d682f7e428845efe8
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4936
Reviewed-by: Alex von Gluck IV <[email protected]>
Reviewed-by: waddlesplash <[email protected]>

configure

@@ -93,6 +93,7 @@ options:
                               specify the path to a GDB source dir, to build
                               GDB for each arch we build the cross-tools for.
   --use-stack-protector       Build with stack protection enabled
+  --efi-signing-key           Private keyfile to sign any EFI bootloaders
 
 environment variables:
   CC                          The host compiler. Defaults to "gcc".
@@ -804,6 +805,11 @@ while [ $# -gt 0 ] ; do
 		--no-xattr)		HAIKU_HOST_USE_XATTR_REF=0; shift 1;;
 		--with-gdb)	gdbSources=$2; shift 2;;
 		--use-stack-protector)	HAIKU_USE_STACK_PROTECTOR=1; shift 1;;
+		--efi-signing-key)
+			assertparam "$1" $#
+			HAIKU_EFI_SIGNING_KEY="$2"
+			shift 2
+			;;
 		*)				echo Invalid argument: \`$1\'; exit 1;;
 	esac
 done
@@ -1112,6 +1118,7 @@ HAIKU_PORTS					?= ${HAIKU_PORTS} ;
 HAIKU_PORTS_CROSS			?= ${HAIKU_PORTS_CROSS} ;
 HAIKU_IS_BOOTSTRAP			?= ${HAIKU_IS_BOOTSTRAP} ;
 
+HAIKU_BOOT_EFI_PRIVATE_KEYFILE	?= ${HAIKU_EFI_SIGNING_KEY} ;
 EOF
 
 for targetArch in $HAIKU_PACKAGING_ARCHS; do