1/* Copyright (c) 2002, 2005, 2006, 2007 Marek Michalkiewicz
2   All rights reserved.
3
4   Redistribution and use in source and binary forms, with or without
5   modification, are permitted provided that the following conditions are met:
6
7   * Redistributions of source code must retain the above copyright
8     notice, this list of conditions and the following disclaimer.
9   * Redistributions in binary form must reproduce the above copyright
10     notice, this list of conditions and the following disclaimer in
11     the documentation and/or other materials provided with the
12     distribution.
13   * Neither the name of the copyright holders nor the names of
14     contributors may be used to endorse or promote products derived
15     from this software without specific prior written permission.
16
17  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  POSSIBILITY OF SUCH DAMAGE. */
28
29/* $Id: strncpy_P.S 2503 2016-02-07 22:59:47Z joerg_wunsch $ */
30
31
32#if !defined(__AVR_TINY__)
33
34#if !defined(__DOXYGEN__)
35
36#include "macros.inc"
37
38#define dest_hi r25
39#define dest_lo r24
40#define src_hi r23
41#define src_lo r22
42#define len_hi r21
43#define len_lo r20
44
45	ASSEMBLY_CLIB_SECTION
46	.global	_U(strncpy_P)
47	.type	_U(strncpy_P), @function
48_U(strncpy_P):
49	X_movw	ZL, src_lo
50	X_movw	XL, dest_lo
51.L_strncpy_P_loop:
52	subi	len_lo, lo8(1)
53	sbci	len_hi, hi8(1)
54	brcs	.L_strncpy_P_done
55	X_lpm	r0, Z+
56	st	X+, r0
57	tst	r0
58	brne	.L_strncpy_P_loop
59; store null characters up to the end of dest
60; as the glibc manual says:
61; This behavior is rarely useful, but it is specified by the ISO C standard.
62	rjmp	.L_strncpy_P_clr_start
63.L_strncpy_P_clr_loop:
64	st	X+, __zero_reg__
65.L_strncpy_P_clr_start:
66	subi	len_lo, lo8(1)
67	sbci	len_hi, hi8(1)
68	brcc	.L_strncpy_P_clr_loop
69.L_strncpy_P_done:
70; return dest (unchanged)
71	ret
72.L_strncpy_P_end:
73	.size	_U(strncpy_P), .L_strncpy_P_end - _U(strncpy_P)
74
75#endif /* not __DOXYGEN__ */
76
77#endif /* !defined(__AVR_TINY__) */
78