$OpenBSD: patch-configure,v 1.35 2013/07/18 20:20:18 brad Exp $
--- configure.orig	Wed Jun 26 17:47:29 2013
+++ configure	Fri Jun 28 00:47:20 2013
@@ -2517,9 +2517,31 @@ fi
 
 ##########################################
 # fdt probe
+# fdt support is mandatory for at least some target architectures,
+# so insist on it if we're building those system emulators.
+fdt_required=no
+for target in $target_list; do
+  case $target in
+    arm*-softmmu|ppc*-softmmu|microblaze*-softmmu)
+      fdt_required=yes
+    ;;
+  esac
+done
+
+if test "$fdt_required" = "yes"; then
+  if test "$fdt" = "no"; then
+    error_exit "fdt disabled but some requested targets require it." \
+      "You can turn off fdt only if you also disable all the system emulation" \
+      "targets which need it (by specifying a cut down --target-list)."
+  fi
+  fdt=yes
+fi
+
 if test "$fdt" != "no" ; then
   fdt_libs="-lfdt"
+  # explicitly check for libfdt_env.h as it is missing in some stable installs
   cat > $TMPC << EOF
+#include <libfdt_env.h>
 int main(void) { return 0; }
 EOF
   if compile_prog "" "$fdt_libs" ; then
@@ -3389,8 +3411,6 @@ fi
 if test "$gcov" = "yes" ; then
   CFLAGS="-fprofile-arcs -ftest-coverage -g $CFLAGS"
   LDFLAGS="-fprofile-arcs -ftest-coverage $LDFLAGS"
-elif test "$debug" = "no" ; then
-  CFLAGS="-O2 -D_FORTIFY_SOURCE=2 $CFLAGS"
 fi
 
 
