libfdt: Import libfdt source (1 of 2)
This adds the applicable libfdt source files (unmodified) and a README
to explain where the source came from.
diff --git a/include/libfdt_env.h b/include/libfdt_env.h
new file mode 100644
index 0000000..59f2536
--- /dev/null
+++ b/include/libfdt_env.h
@@ -0,0 +1,22 @@
+#ifndef _LIBFDT_ENV_H
+#define _LIBFDT_ENV_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <endian.h>
+#include <byteswap.h>
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+#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) (bswap_32((x)))
+#define cpu_to_fdt32(x) (bswap_32((x)))
+#define fdt64_to_cpu(x) (bswap_64((x)))
+#define cpu_to_fdt64(x) (bswap_64((x)))
+#endif
+
+#endif /* _LIBFDT_ENV_H */