diff --git a/components/free_rtos/base/swap.h b/components/free_rtos/base/swap.h
index 1827509..153ee80 100644
--- a/components/free_rtos/base/swap.h
+++ b/components/free_rtos/base/swap.h
@@ -10,10 +10,10 @@
 
 #include <arm_acle.h>
 
-//#define BASE_SWAP32(value) __builtin_bswap32(value)
-#define BASE_SWAP32(value) __rev(value)
+#define BASE_SWAP32(value) __builtin_bswap32(value)
+//#define BASE_SWAP32(value) __rev(value)
 
-//#define BASE_SWAP16(value) (uint16_t)__builtin_bswap16(value)
-#define BASE_SWAP16(value) (uint16_t)__rev16(value)
+#define BASE_SWAP16(value) (uint16_t)__builtin_bswap16(value)
+//#define BASE_SWAP16(value) (uint16_t)__rev16(value)
 
 #endif /* FREE_RTOS_BASE_SWAP_H_ */
diff --git a/components/free_rtos/ethernet_ip/eth_checksum.c b/components/free_rtos/ethernet_ip/eth_checksum.c
index 1feb666..a6307cd 100644
--- a/components/free_rtos/ethernet_ip/eth_checksum.c
+++ b/components/free_rtos/ethernet_ip/eth_checksum.c
@@ -8,6 +8,7 @@
 #include "free_rtos/base/swap.h"
 
 #include <arm_acle.h>
+#include <string.h>
 
 uint16_t eth_calcChksum(uint32_t sum, uint8_t * const data, uint16_t len)
 {
@@ -56,69 +57,60 @@ uint16_t eth_calcChksum2(uint32_t sum, uint8_t * const hdata, uint16_t hlen, uin
     return ~sum;
 }
 
-union PointerConverter
-{
-    void * unknown;
-    uint64_t * octet;
-    uint32_t * quartet;
-    uint16_t * duet;
-    uint8_t * solo;
-};
-
-struct Array {
-    uint16_t duet0;
-    uint16_t duet1;
-    uint16_t duet2;
-    uint16_t duet3;
-};
-
-union ValueConverter
-{
-    uint64_t octet;
-    uint32_t quartet;
-    uint16_t duet;
-    uint8_t solo;
-    struct Array array;
-};
-
 uint32_t calcSum(void * const buffer, uint32_t sum, void * const data, uint16_t len)
 {
-    union PointerConverter buffer_start;
-    union PointerConverter data_start;
-    union ValueConverter value;
+    uint8_t* buffer_start;
+    uint8_t* data_start;
+    uint32_t value;
 
-    buffer_start.unknown = buffer;
-    data_start.unknown = data;
+    buffer_start = (uint8_t*)buffer;
+    data_start = (uint8_t*)data;
+    value = 0x00000000;
 
-    while(len >= sizeof(uint32_t)) {
-        len -= sizeof(uint32_t);
+    #define SIZE sizeof(uint32_t)
+    while(len >= SIZE) {
+        len -= SIZE;
 
-        value.quartet = *data_start.quartet++;
-        *buffer_start.quartet++ = value.quartet;
+        memcpy(&value, data_start, SIZE);
+        data_start += SIZE;
 
-        value.quartet = __rev16(value.quartet);
-        sum += value.array.duet0 + value.array.duet1;
+        memcpy(buffer_start, &value, SIZE);
+        buffer_start += SIZE;
+
+        value = __rev16(value);
+        sum += (value&0xFFFF) + (value>>16);
     }
+    #undef SIZE
 
-    if(len >= sizeof(uint16_t)) {
-        len -= sizeof(uint16_t);
+    #define SIZE sizeof(uint16_t)
+    if(len >= SIZE) {
+        len -= SIZE;
+        value = 0x00000000;
 
-        value.duet = *data_start.duet++;
-        *buffer_start.duet++ = value.duet;
+        memcpy(&value, data_start, SIZE);
+        data_start += SIZE;
 
-        value.quartet = __rev16(value.quartet);
-        sum += value.duet;
+        memcpy(buffer_start, &value, SIZE);
+        buffer_start += SIZE;
+
+        sum += __rev16(value);
     }
+    #undef SIZE
 
-    if(len >= sizeof(uint8_t)) {
-        len -= sizeof(uint8_t);
+    #define SIZE sizeof(uint8_t)
+    if(len >= SIZE) {
+        len -= SIZE;
+        value = 0x00000000;
 
-        value.solo = *data_start.solo++;
-        *buffer_start.solo++ = value.solo;
+        memcpy(&value, data_start, SIZE);
+        data_start += SIZE;
 
-        value.quartet = __rev16(value.quartet);
-        sum += value.solo;
+        memcpy(buffer_start, &value, SIZE);
+        buffer_start += SIZE;
+
+        sum += __rev16(value);
     }
+    #undef SIZE
 
     return sum;
 }