1/*
2 * Copyright 2005-2010 Analog Devices Inc.
3 *
4 * Licensed under the Clear BSD license or the GPL-2 (or later)
5 */
6
7#include <linux/linkage.h>
8#include <asm/context.S>
9
10/* void *strncpy(char *dest, const char *src, size_t n);
11 * R0 = address (dest)
12 * R1 = address (src)
13 * R2 = size
14 * Returns a pointer (R0) to the destination string dest
15 *  we do this by not changing R0
16 */
17
18#ifdef CONFIG_STRNCPY_L1
19.section .l1.text
20#else
21.text
22#endif
23
24.align 2
25
26ENTRY(_strncpy)
27	CC = R2 == 0;
28	if CC JUMP 6f;
29
30	P2 = R2 ;       /* size */
31	P0 = R0 ;       /* dst*/
32	P1 = R1 ;       /* src*/
33
34	LSETUP (1f, 2f) LC0 = P2;
351:
36	R1 = B [P1++] (Z);
37	B [P0++] = R1;
38	CC = R1 == 0;
392:
40	if CC jump 3f;
41
42	RTS;
43
44	/* if src is shorter than n, we need to null pad bytes in dest
45	 * but, we can get here when the last byte is zero, and we don't
46	 * want to copy an extra byte at the end, so we need to check
47	 */
483:
49	R2 = LC0;
50	CC = R2
51	if ! CC jump 6f;
52
53	/* if the required null padded portion is small, do it here, rather than
54	 * handling the overhead of memset (which is OK when things are big).
55	 */
56	R3 = 0x20;
57	CC = R2 < R3;
58	IF CC jump 4f;
59
60	R2 += -1;
61
62	/* Set things up for memset
63	 * R0 = address
64	 * R1 = filler byte (this case it's zero, set above)
65	 * R2 = count (set above)
66	 */
67
68	I1 = R0;
69	R0 = RETS;
70	I0 = R0;
71	R0 = P0;
72	pseudo_long_call _memset, p0;
73	R0 = I0;
74	RETS = R0;
75	R0 = I1;
76	RTS;
77
784:
79	LSETUP(5f, 5f) LC0;
805:
81	B [P0++] = R1;
826:
83	RTS;
84
85ENDPROC(_strncpy)
86