Index: head/release/amd64/mkisoimages.sh
===================================================================
--- head/release/amd64/mkisoimages.sh
+++ head/release/amd64/mkisoimages.sh
@@ -38,7 +38,7 @@
 	umount efi
 	rmdir efi
 	mdconfig -d -u $device
-	bootable="-o bootimage=i386;efiboot.img -o no-emul-boot -o platformid=efi $bootable"
+	bootable="$bootable -o bootimage=i386;efiboot.img -o no-emul-boot -o platformid=efi"
 	
 	shift
 else
@@ -58,3 +58,29 @@
 makefs -t cd9660 $bootable -o rockridge -o label="$LABEL" -o publisher="$publisher" "$NAME" "$@"
 rm -f "$1/etc/fstab"
 rm -f efiboot.img
+
+if [ "$bootable" != "" ]; then
+	# Look for the EFI System Partition image we dropped in the ISO image.
+	for entry in `etdump --format shell $NAME`; do
+		eval $entry
+		if [ "$et_platform" = "efi" ]; then
+			espstart=`expr $et_lba \* 2048`
+			espsize=`expr $et_sectors \* 512`
+			espparam="-p efi::$espsize:$espstart"
+			break
+		fi
+	done
+
+	# Create a GPT image containing the partitions we need for hybrid boot.
+	imgsize=`stat -f %z $NAME`
+	mkimg -s gpt \
+	    --capacity $imgsize \
+	    -b $4/boot/pmbr \
+	    $espparam \
+	    -p freebsd-boot:=$4/boot/isoboot \
+	    -o hybrid.img
+
+	# Drop the PMBR, GPT, and boot code into the System Area of the ISO.
+	dd if=hybrid.img of=$NAME bs=32k count=1 conv=notrunc
+	rm -f hybrid.img
+fi