tools: check for libfdt when building for ARM

libxl is going to want this to aid in the creation of guest device tree blobs.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

tools/config.h.in

@@ -9,6 +9,9 @@
 /* Define to 1 if you have the `crypto' library (-lcrypto). */
 #undef HAVE_LIBCRYPTO
 
+/* Define to 1 if you have the `fdt' library (-lfdt). */
+#undef HAVE_LIBFDT
+
 /* Define to 1 if you have the `yajl' library (-lyajl). */
 #undef HAVE_LIBYAJL
 

tools/configure

@@ -7959,6 +7959,58 @@ fi
 
 
 
+# FDT is needed only on ARM
+case "$host_cpu" in
+arm*|aarch64)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for fdt_create in -lfdt" >&5
+$as_echo_n "checking for fdt_create in -lfdt... " >&6; }
+if ${ac_cv_lib_fdt_fdt_create+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lfdt  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char fdt_create ();
+int
+main ()
+{
+return fdt_create ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_fdt_fdt_create=yes
+else
+  ac_cv_lib_fdt_fdt_create=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_fdt_fdt_create" >&5
+$as_echo "$ac_cv_lib_fdt_fdt_create" >&6; }
+if test "x$ac_cv_lib_fdt_fdt_create" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBFDT 1
+_ACEOF
+
+  LIBS="-lfdt $LIBS"
+
+else
+  as_fn_error $? "Could not find libfdt" "$LINENO" 5
+fi
+
+esac
+
 # Checks for header files.
 for ac_header in yajl/yajl_version.h sys/eventfd.h
 do :

tools/configure.ac

@@ -227,6 +227,12 @@ AC_CHECK_LIB([z], [deflateCopy], [], [AC_MSG_ERROR([Could not find zlib])])
 AC_CHECK_LIB([iconv], [libiconv_open], [libiconv="y"], [libiconv="n"])
 AC_SUBST(libiconv)
 
+# FDT is needed only on ARM
+case "$host_cpu" in
+arm*|aarch64)
+AC_CHECK_LIB([fdt], [fdt_create], [], [AC_MSG_ERROR([Could not find libfdt])])
+esac
+
 # Checks for header files.
 AC_CHECK_HEADERS([yajl/yajl_version.h sys/eventfd.h])