implement software endianness byte-swapping

endian.c

@@ -21,7 +21,35 @@ static enum cu_endian_e endian_detect()
     else return MiddleEndian;
 }
 
+static uint16_t sw_bswap16(uint16_t val)
+{
+    return (val << 8) | (val >> 8);
+}
+
+static uint32_t sw_bswap32(uint32_t val)
+{
+    return  ((val >> 24) & 0xFF) << 0
+        |   ((val >> 16) & 0xFF) << 8
+        |   ((val >> 8) & 0xFF) << 16
+        |   ((val >> 0) & 0xFF) << 24;
+}
+
+static uint64_t sw_bswap64(uint64_t val)
+{
+    return  ((val >> 56) & 0xFF) << 0
+        |   ((val >> 48) & 0xFF) << 8
+        |   ((val >> 40) & 0xFF) << 16
+        |   ((val >> 32) & 0xFF) << 24
+        |   ((val >> 24) & 0xFF) << 32
+        |   ((val >> 16) & 0xFF) << 40
+        |   ((val >> 8) & 0xFF) << 48
+        |   ((val >> 0) & 0xFF) << 56;
+}
+
+#include <stdio.h>
+
 void cu_endian_init()
 {
     cu_endian = endian_detect();
+    printf("%lx\t%lx\n", 0x12345678abcd8765, sw_bswap64(0x12345678abcd8765));
 }