diff --git a/firmware/export/system.h b/firmware/export/system.h
index 1205e9360b..09efbeeda4 100644
--- a/firmware/export/system.h
+++ b/firmware/export/system.h
@@ -155,6 +155,28 @@ static inline int set_irq_level(int level)
     return oldlevel;
 }
 
+static inline unsigned short SWAB16(unsigned short value)
+  /*
+    result[15..8] = value[ 7..0];
+    result[ 7..0] = value[15..8];
+  */    
+{
+    return (value >> 8) | (value << 8);
+}
+
+static inline unsigned long SWAB32(unsigned long value)
+  /*
+    result[31..24] = value[ 7.. 0];
+    result[23..16] = value[15.. 8];
+    result[15.. 8] = value[23..16];
+    result[ 7.. 0] = value[31..24];
+  */    
+{
+    unsigned short hi = SWAB16(value >> 16);
+    unsigned short lo = SWAB16(value & 0xffff);
+    return (lo << 16) | hi;
+}
+
 #endif
 #endif