diff --git a/lib/libc/string/swab.c b/lib/libc/string/swab.c
new file mode 100644
index 0000000..ef3f6f0
--- /dev/null
+++ b/lib/libc/string/swab.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 1988, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jeffrey Mogul.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifdef __ORCAC__
+segment "libc_str__";
+#endif
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)swab.c	8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+
+#include <string.h>
+
+void
+#ifdef __ORCAC__
+swab(const void *from, void *to, size_t len)
+#else
+swab(from, to, len)
+	const void *from;
+	void *to;
+	size_t len;
+#endif
+{
+	register unsigned long temp;
+	register int n;
+	register char *fp, *tp;
+
+	n = (len >> 1) + 1;
+	fp = (char *)from;
+	tp = (char *)to;
+#define	STEP	temp = *fp++,*tp++ = *fp++,*tp++ = temp
+	/* round to multiple of 8 */
+	while ((--n) & 07)
+		STEP;
+	n >>= 3;
+	while (--n >= 0) {
+		STEP; STEP; STEP; STEP;
+		STEP; STEP; STEP; STEP;
+	}
+}