switch to grub2 eltorito from ancient syslinux v4,

update grub2,
predd 'd' in grub to show debug menu.

build

@@ -16,7 +16,7 @@ exec > >(tee -i /tmp/mlb.log) 2>&1
 cd "$(dirname $(readlink -f ${0}))" || exit 1
 cp -f config .config
 
-mapfile -t list < <(ls -A /boot | egrep "^bzImage*|*kernel*|^vmlinuz*" 2>/dev/null | grep -v "init")
+mapfile -t list < <(ls -A /boot | egrep "bzImage|kernel|vmlinuz" 2>/dev/null | egrep -v "init|*.old")
 if [ ${#list[@]} -gt 1 ]; then
 	n=0
 	echo -e "Please choose your kernel to proceed:\nChoose number from ${n} to ${#list[@]}\n-----\n"
@@ -61,7 +61,6 @@ time (
 	done
 	mv -f ${INITRD} ${DATA}/initrd.img
 	cp -rf bootfiles/* ${DATA}
-	mv -f ${tmpRoot}/tmp/grub_efi.img ${DATA}/efi.img
 	for i in ${DATA}/syslinux.cfg ${DATA}/boot/grub/grub.cfg; do
 		sed -i -r "s/__DISTRO__/${DISTRO}/" ${i}
 	done
@@ -76,7 +75,7 @@ MLB_NAME="${DISTRO}"
 MLB_UTC="${utc}"
 eot
 	[[ ${ret} = 2 ]]&&echo "MLB_ELF_STATIC_INITRD=\"1\"" >>.MlbMeta||echo "MLB_ELF_STATIC_INITRD=\"0\"" >>.MlbMeta
-	xorriso -as mkisofs -o /${DISTRO}-${utc}.iso -iso-level 3 -J -R -D -A ${DISTRO} -V ${DISTRO} -no-emul-boot -boot-info-table -boot-load-size 4 -b isolinux.bin -c isolinux.boot -eltorito-alt-boot -e /efi.img -no-emul-boot .
+	xorriso -as mkisofs -o /${DISTRO}-${utc}.iso -iso-level 3 -J -R -D -A ${DISTRO} -V ${DISTRO} -no-emul-boot -boot-info-table -boot-load-size 2 -b boot/grub/i386-pc/eltorito.img -c boot/grub/grub.cat -eltorito-alt-boot -e /efi.img -no-emul-boot .
 	isohybrid --version >/dev/null 2>&1&&isohybrid -u /${DISTRO}-${utc}.iso
 	cd ${top}
 	rm -rf ${workTmpDir}