diff --git a/util/cbfstool/swab.h b/util/cbfstool/swab.h
new file mode 100644
index 0000000..c5e4370
--- /dev/null
+++ b/util/cbfstool/swab.h
@@ -0,0 +1,44 @@
+#ifndef _SWAB_H
+#define _SWAB_H
+
+/*
+ * linux/byteorder/swab.h
+ * Byte-swapping, independently from CPU endianness
+ *	swabXX[ps]?(foo)
+ *
+ * Francois-Rene Rideau <fare@tunes.org> 19971205
+ *    separated swab functions from cpu_to_XX,
+ *    to clean up support for bizarre-endian architectures.
+ *
+ * See asm-i386/byteorder.h and suches for examples of how to provide
+ * architecture-dependent optimized versions
+ *
+ */
+
+/* casts are necessary for constants, because we never know how for sure
+ * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
+ */
+#define swab16(x) \
+	((unsigned short)( \
+		(((unsigned short)(x) & (unsigned short)0x00ffU) << 8) | \
+		(((unsigned short)(x) & (unsigned short)0xff00U) >> 8) ))
+
+#define swab32(x) \
+	((unsigned int)( \
+		(((unsigned int)(x) & (unsigned int)0x000000ffUL) << 24) | \
+		(((unsigned int)(x) & (unsigned int)0x0000ff00UL) <<  8) | \
+		(((unsigned int)(x) & (unsigned int)0x00ff0000UL) >>  8) | \
+		(((unsigned int)(x) & (unsigned int)0xff000000UL) >> 24) ))
+
+#define swab64(x) \
+	((uint64_t)( \
+		(((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) | \
+		(((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) | \
+		(((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) | \
+		(((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) <<  8) | \
+		(((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >>  8) | \
+		(((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) | \
+		(((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) | \
+		(((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56) ))
+
+#endif /* _SWAB_H */