diff --git a/libc/arch-x86/string/bcopy.S b/libc/arch-x86/string/bcopy.S
new file mode 100644
index 0000000..dde5ae1
--- /dev/null
+++ b/libc/arch-x86/string/bcopy.S
@@ -0,0 +1,93 @@
+/*	$OpenBSD: bcopy.S,v 1.5 2005/08/07 11:30:38 espie Exp $	*/
+
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from locore.s.
+ *
+ * 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. 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.
+ */
+
+#include <machine/asm.h>
+
+	/*
+	 * (ov)bcopy (src,dst,cnt)
+	 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
+	 */
+
+#ifdef MEMCOPY
+ENTRY(memcpy)
+#else
+#ifdef MEMMOVE
+ENTRY(memmove)
+#else
+ENTRY(bcopy)
+#endif
+#endif
+	pushl	%esi
+	pushl	%edi
+#if defined(MEMCOPY) || defined(MEMMOVE)
+	movl	12(%esp),%edi
+	movl	16(%esp),%esi
+	movl	%edi, %eax
+#else
+	movl	12(%esp),%esi
+	movl	16(%esp),%edi
+#endif
+	movl	20(%esp),%ecx
+	movl	%ecx,%edx
+	cmpl	%esi,%edi	/* potentially overlapping? */
+	jnb	1f
+	cld			/* nope, copy forwards. */
+	shrl	$2,%ecx		/* copy by words */
+	rep
+	movsl
+	movl	%edx,%ecx
+	andl	$3,%ecx		/* any bytes left? */
+	rep
+	movsb
+	popl	%edi
+	popl	%esi
+	ret
+1:
+	addl	%ecx,%edi	/* copy backwards. */
+	addl	%ecx,%esi
+	std
+	andl	$3,%ecx		/* any fractional bytes? */
+	decl	%edi
+	decl	%esi
+	rep
+	movsb
+	movl	%edx,%ecx
+	shrl	$2,%ecx
+	subl	$3,%esi
+	subl	$3,%edi
+	rep
+	movsl
+	popl	%edi
+	popl	%esi
+	cld
+	ret