configure: dtc: Probe for libfdt_env.h

Currently QEMU provides a local clone of the file libfdt_env.h in
/include. This file is supposed to come with the libfdt package and is
only needed for broken installs of libfdt. Now that we have submodule
dtc, just ignore these broken installs and prompt for the dtc submodule
install instead. QEMU's local libfdt_env.h is removed accordingly.

Manifests as a bug when building QEMU with modern libfdt. The new
version of libfdt does not compile when QEMUs libfdt_env.h takes
precedence over the hosts.
Signed-off-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Acked-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NKim Phillips <kim.phillips@freescale.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 9b6a3a52e3f46cfbc1ded9ab56385ec045e46705.1369628289.git.peter.crosthwaite@xilinx.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

configure

@@ -2488,7 +2488,9 @@ fi
 # fdt probe
 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

include/libfdt_env.h

-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 2, as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see <http://www.gnu.org/licenses/>.
- *
- * Copyright IBM Corp. 2008
- * Authors: Hollis Blanchard <hollisb@us.ibm.com>
- *
- */
-
-#ifndef _LIBFDT_ENV_H
-#define _LIBFDT_ENV_H
-
-#include "qemu/bswap.h"
-
-#ifdef HOST_WORDS_BIGENDIAN
-#define fdt32_to_cpu(x)  (x)
-#define cpu_to_fdt32(x)  (x)
-#define fdt64_to_cpu(x)  (x)
-#define cpu_to_fdt64(x)  (x)
-#else
-#define fdt32_to_cpu(x)  bswap32(x)
-#define cpu_to_fdt32(x)  bswap32(x)
-#define fdt64_to_cpu(x)  bswap64(x)
-#define cpu_to_fdt64(x)  bswap64(x)
-#endif
-
-#endif /* _LIBFDT_ENV_H */