[libc] Rewrite byte-swapping code

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 16 insertions, 15 deletions

diff --git a/src/include/endian.h b/src/include/endian.h
index 9682cf9b4..79c3163ee 100644
--- a/src/include/endian.h
+++ b/src/include/endian.h
@@ -1,21 +1,22 @@
-#ifndef ETHERBOOT_ENDIAN_H
-#define ETHERBOOT_ENDIAN_H
+#ifndef _ENDIAN_H
+#define _ENDIAN_H
 
-FILE_LICENCE ( GPL2_OR_LATER );
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
-/* Definitions for byte order, according to significance of bytes,
-   from low addresses to high addresses.  The value is what you get by
-   putting '4' in the most significant byte, '3' in the second most
-   significant byte, '2' in the second least significant byte, and '1'
-   in the least significant byte, and then writing down one digit for
-   each byte, starting with the byte at the lowest address at the left,
-   and proceeding to the byte with the highest address at the right.  */
+/** Constant representing little-endian byte order
+ *
+ * Little-endian systems should define BYTE_ORDER as LITTLE_ENDIAN.
+ * This constant is intended to be used only at compile time.
+ */
+#define __LITTLE_ENDIAN 0x44332211UL
 
-#define __LITTLE_ENDIAN 1234
-#define __BIG_ENDIAN    4321
-#define __PDP_ENDIAN    3412
+/** Constant representing big-endian byte order
+ *
+ * Big-endian systems should define BYTE_ORDER as BIG_ENDIAN.
+ * This constant is intended to be used only at compile time.
+ */
+#define __BIG_ENDIAN 0x11223344UL
 
 #include "bits/endian.h"
 
-
-#endif /* ETHERBOOT_ENDIAN_H */
+#endif /* _ENDIAN_H */