This patch is borrowed from Debian's patches for plink

Author: Peter Green <plugwash@p10link.net>
Puropose: Fallback to endian.h if all else fails on 64bit machines
Closes: #528659
Forwarded: Shaun Purcell <plink@chgr.mgh.harvard.edu>
License: same as plink itself.
===================================================================
--- plink-1.06.orig/Rsrv.h	2009-05-15 03:35:29.000000000 +0100
+++ plink-1.06/Rsrv.h	2009-05-15 03:35:41.000000000 +0100
@@ -313,7 +313,18 @@
 #define __BIG_ENDIAN__ 1
 #define SWAPEND 1
 #elif ! defined Win32 /* Windows is little-endian is most cases, anywhere else we're stuck */
-#error "Cannot determine endianness. Make sure config.h is included or __{BIG|LITTLE}_ENDIAN__ is defined ."
+  //try endian.h before we finally bail out
+  #include <endian.h>
+  #if __BYTE_ORDER == __LITTLE_ENDIAN
+    #warning using little endian based on information from endian.h
+    #define __LITTLE_ENDIAN__ 1
+  #elif __BYTE_ORDER == __BIG_ENDIAN
+    #warning using big endian based on information from endian.h
+    #define __BIG_ENDIAN__ 1
+    #define SWAPEND 1
+  #else    
+    #error "Cannot determine endianness. Make sure config.h is included or __{BIG|LITTLE}_ENDIAN__ is defined ."
+  #endif    
 #endif
 
 /* FIXME: all the mess below needs more efficient implementation - the current one is so messy to work around alignment problems on some platforms like Sun and HP 9000 */