diff --git a/configure b/configure
index 6c33f22..9dddba6 100755
--- a/configure
+++ b/configure
@@ -509,6 +509,7 @@
 default_devices="yes"
 plugins="no"
 fuzzing="no"
+tasn1="yes"
 
 supported_cpu="no"
 supported_os="no"
@@ -905,6 +906,7 @@
   QEMU_INCLUDES="-isystem \$(SRC_PATH)/linux-headers -isystem $PWD/linux-headers $QEMU_INCLUDES"
   supported_os="yes"
   libudev="yes"
+  x11=""
 ;;
 esac
 
@@ -1104,7 +1106,9 @@
   ;;
   --disable-sdl) sdl="no"
   ;;
-  --enable-sdl) sdl="yes"
+  --enable-sdl) sdl="system"
+  ;;
+  --enable-sdl=*) sdl="$optarg"
   ;;
   --disable-sdl-image) sdl_image="no"
   ;;
@@ -1291,6 +1295,10 @@
   ;;
   --enable-fdt) fdt="yes"
   ;;
+  --with-system-fdt) fdt="system"
+  ;;
+  --without-system-fdt) fdt="internal"
+  ;;
   --disable-linux-aio) linux_aio="no"
   ;;
   --enable-linux-aio) linux_aio="yes"
@@ -1355,6 +1363,10 @@
   ;;
   --enable-rbd) rbd="yes"
   ;;
+  --disable-x11) x11="no"
+  ;;
+  --enable-x11) x11="yes"
+  ;;
   --disable-xfsctl) xfs="no"
   ;;
   --enable-xfsctl) xfs="yes"
@@ -1601,6 +1613,10 @@
   ;;
   --gdb=*) gdb_bin="$optarg"
   ;;
+  --disable-tasn1) tasn1="no"
+  ;;
+  --enable-tasn1) tasn1="yes"
+  ;;
   *)
       echo "ERROR: unknown option $opt"
       echo "Try '$0 --help' for more information"
@@ -2885,10 +2901,14 @@
 
 ##########################################
 # X11 probe
-if $pkg_config --exists "x11"; then
-    have_x11=yes
-    x11_cflags=$($pkg_config --cflags x11)
-    x11_libs=$($pkg_config --libs x11)
+if test "$x11" != "no"; then
+  have_x11=yes
+  x11_cflags=
+  x11_libs=-lX11
+  if $pkg_config --exists "x11"; then
+      x11_cflags=$($pkg_config --cflags x11)
+      x11_libs=$($pkg_config --libs x11)
+  fi
 fi
 
 ##########################################
@@ -3090,14 +3110,15 @@
 ##########################################
 # libtasn1 - only for the TLS creds/session test suite
 
-tasn1=yes
 tasn1_cflags=""
 tasn1_libs=""
-if $pkg_config --exists "libtasn1"; then
-    tasn1_cflags=$($pkg_config --cflags libtasn1)
-    tasn1_libs=$($pkg_config --libs libtasn1)
-else
-    tasn1=no
+if test "$tasn1" = "yes" ; then
+    if $pkg_config --exists "libtasn1"; then
+        tasn1_cflags=$($pkg_config --cflags libtasn1)
+        tasn1_libs=$($pkg_config --libs libtasn1)
+    else
+        tasn1=no
+    fi
 fi