Index: lib/libc/powerpc64/string/Makefile.inc
===================================================================
--- /dev/null
+++ lib/libc/powerpc64/string/Makefile.inc
@@ -0,0 +1,4 @@
+# $FreeBSD$
+
+MDSRCS+= \
+	strncpy.S
Index: lib/libc/powerpc64/string/strncpy.S
===================================================================
--- /dev/null
+++ lib/libc/powerpc64/string/strncpy.S
@@ -0,0 +1,165 @@
+/*-
+ * Copyright (c) 2018 Instituto de Pesquisas Eldorado
+ * All rights reserved.
+ *
+ * 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 author nor the names of its contributors may
+ *    be used to endorse or promote products derived from this software
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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>
+__FBSDID("$FreeBSD$");
+
+#if 0
+	RCSID("$NetBSD: strncpy.S,v 1.0 2018/05/08 13:00:05 lbianc Exp $")
+#endif
+
+ENTRY(strncpy)
+	std	3,-8(1)
+
+	xor	6,6,6     /* Perare register with zero value. */
+
+	cmpdi	cr7,5,0
+	ble	cr7,.Lexit
+
+/* Copy by double word. */
+.Lcopy_dw:
+	cmpdi	cr7,5,8
+	blt	cr7,.Lstd_byte
+	ld	0,0(4)
+	cmpb	7,0,6
+	cmpdi	cr7,7,0
+	bne	cr7,.Lcheck_zero
+	std	0,0(3)
+	addi	5,5,-8
+	cmpdi	cr7,5,0
+	beq	cr7,.Lexit
+	cmpdi	cr7,5,8
+	blt	cr7,.Lstd_byte_fix
+.Lcopy_dw_loop:
+	ldu	0,8(4)
+	cmpb	7,0,6
+	cmpdi	cr7,7,0
+	bne	cr7,.Lcheck_zero_fix
+	stdu	0,8(3)
+	addi	5,5,-8
+	cmpdi	cr7,5,8
+	bge	cr7,.Lcopy_dw_loop
+	cmpdi	cr7,5,0
+	bne	cr7,.Lstd_byte_fix
+	ld	3,-8(1)
+	blr
+
+/* Copy by byte */
+.Lstd_byte_fix:
+	addi	3,3,8  /* Fix addresses from update instructions. */
+	addi	4,4,8
+.Lstd_byte:
+        cmpdi 0,5,0
+        beqlr 0
+        addi 9,5,-1
+        addi 10,3,-1
+        rldicl 9,9,0,32
+        addi 9,9,1
+        mtctr 9
+.Lstd_byte_loop:
+        lbz 9,0(4)
+        addic 8,9,-1
+        stbu 9,1(10)
+        addze 4,4
+        bdnz .Lstd_byte_loop
+        blr
+
+/* Store zeros by byte. */
+.Lstd_byte_z:
+	stb	6,0(3)
+	addi	5,5,-1
+	cmpdi	cr7,5,0
+	beq	cr7,.Lexit
+	addi	3,3,1
+	b	.Lstd_byte_z
+
+/* Fin where the zero is located. */
+.Lcheck_zero_fix:
+	addi	3,3,8
+.Lcheck_zero:
+	addi	5,5,-8
+	rldicr.	7,0,0,7
+	beq	.Lfound_on_byte_1
+	rldicr.	7,0,8,7
+	beq	.Lfound_on_byte_2
+	rldicr.	7,0,16,7
+	beq	.Lfound_on_byte_3
+	rldicr.	7,0,24,7
+	beq	.Lfound_on_byte_4
+	andis.	7,0,0xff00
+	beq	.Lfound_on_byte_5
+	andis.	7,0,0xff
+	beq	.Lfound_on_byte_6
+	andi.	7,0,0xff00
+	beq	.Lfound_on_byte_7
+
+/* As zero was found in a double word before r5 be zero, store the entire
+   register with zeros after the end of the string */
+.Lstd_dw:
+	std	0,0(3)
+	addi	3,3,8
+	cmpdi	cr7,5,0
+	beq	cr7,.Lexit
+	b	.Lstd_byte_z
+
+/* Treatment of each byte where the zero my be found. */
+.Lfound_on_byte_7:
+	rldicr	0,0,0,56
+	b	.Lstd_dw
+
+.Lfound_on_byte_6:
+	rldicr	0,0,0,48
+	b	.Lstd_dw
+
+.Lfound_on_byte_5:
+	rldicr	0,0,0,40
+	b	.Lstd_dw
+
+.Lfound_on_byte_4:
+	rldicr	0,0,0,32
+	b	.Lstd_dw
+
+.Lfound_on_byte_3:
+	rldicr	0,0,0,24
+	b	.Lstd_dw
+
+.Lfound_on_byte_2:
+	rldicr	0,0,0,16
+	b	.Lstd_dw
+
+.Lfound_on_byte_1:
+	mr	0,6
+	b	.Lstd_dw
+
+.Lexit:
+	ld	3,-8(1)
+	blr
+
+END(strncpy)
+
+        .section .note.GNU-stack,"",%progbits