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Wolfgang Denk460c2ce2010-06-21 22:29:59 +02001/*
2 * (C) Copyright 2010
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02005 * SPDX-License-Identifier: GPL-2.0+
Wolfgang Denk460c2ce2010-06-21 22:29:59 +02006 */
7
8/*
9 * This is a workaround for issues on the MPC5200, where unaligned
10 * 32-bit-accesses to the local bus will deliver corrupted data. This
11 * happens for example when trying to use memcpy() from an odd NOR
12 * flash address; the behaviour can be also seen when using "md" on an
13 * odd NOR flash address (but there it is not a bug in U-Boot, which
14 * only shows the behaviour of this processor).
15 *
16 * For memcpy(), we test if either the source or the target address
17 * are not 32 bit aligned, and - if so - if the source address is in
18 * NOR flash: in this case we perform a byte-wise (slow) then; for
19 * aligned operations of non-flash areas we use the optimized (fast)
20 * real __memcpy(). This way we minimize the performance impact of
21 * this workaround.
22 *
23 */
24
25#include <common.h>
26#include <flash.h>
27#include <linux/types.h>
28
29void *memcpy(void *trg, const void *src, size_t len)
30{
31 extern void* __memcpy(void *, const void *, size_t);
32 char *s = (char *)src;
33 char *t = (char *)trg;
34 void *dest = (void *)src;
35
36 /*
37 * Check is source address is in flash:
38 * If not, we use the fast assembler code
39 */
40 if (((((unsigned long)s & 3) == 0) /* source aligned */
41 && /* AND */
42 (((unsigned long)t & 3) == 0)) /* target aligned, */
43 || /* or */
44 (addr2info((ulong)s) == NULL)) { /* source not in flash */
45 return __memcpy(trg, src, len);
46 }
47
48 /*
49 * Copying from flash, perform byte by byte copy.
50 */
51 while (len-- > 0)
52 *t++ = *s++;
53
54 return dest;
55}