add 64bit extlinux

tools/isolinux.bin.update

@@ -19,7 +19,7 @@ read DIR
 
 # download, unpack, and patch syslinux
 
-apt-get build-dep syslinux
+apt-get --yes build-dep syslinux
 mkdir -m 0777 /tmp/syslinux
 cd /tmp/syslinux
 apt-get source syslinux
@@ -41,7 +41,12 @@ cp bios/com32/elflink/ldlinux/ldlinux.c32 $CWD
 cp bios/com32/lib/libcom32.c32 $CWD
 cp bios/com32/libutil/libutil.c32 $CWD
 cp bios/com32/menu/vesamenu.c32 $CWD
-cp bios/extlinux/extlinux $CWD/extlinux.exe
-strip --strip-unneeded $CWD/extlinux.exe
+
+ARCH=$(uname -m)
+if [ "$ARCH" = "x86_64" ]; then ARCH=64; else ARCH=32; fi
+EXTLINUX=extlinux.x$ARCH
+
+strip --strip-unneeded bios/extlinux/extlinux
+cp bios/extlinux/extlinux $CWD/extlinux.x$ARCH
 
 echo "done"