add byteorder.h

1 files changed, 22 insertions, 0 deletions

diff --git a/byteorder.h b/byteorder.h
new file mode 100644
index 0000000..7b2f099
--- /dev/null
+++ b/byteorder.h
@@ -0,0 +1,22 @@
+#include <sys/types.h>
+
+#ifndef __BYTE_ORDER
+# ifndef BYTE_ORDER
+#  error unknown byteorder
+# endif
+# define __BYTE_ORDER     BYTE_ORDER
+# define __LITTLE_ENDIAN  LITTLE_ENDIAN
+# define __BIG_ENDIAN     BIG_ENDIAN
+#endif
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+# define le16_to_cpu(x) (x)
+# define le32_to_cpu(x) (x)
+#elif BYTE_ORDER == BIG_ENDIAN
+# define le16_to_cpu(x) (((x>>8) & 0x00ff) |\
+                         ((x<<8) & 0xff00))
+# define le32_to_cpu(x) (((x>>24) & 0x000000ff) |\
+                         ((x>>8)  & 0x0000ff00) |\
+                         ((x<<8)  & 0x00ff0000) |\
+                         ((x<<24) & 0xff000000))
+#endif