| Wolfgang Denk | 1612609 | 2010-06-21 22:29:59 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * (C) Copyright 2010 |
| 3 | * Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
| 4 | * |
| 5 | * See file CREDITS for list of people who contributed to this |
| 6 | * project. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of |
| 11 | * the License, or (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 21 | * MA 02111-1307 USA |
| 22 | */ |
| 23 | |
| 24 | /* |
| 25 | * This is a workaround for issues on the MPC5200, where unaligned |
| 26 | * 32-bit-accesses to the local bus will deliver corrupted data. This |
| 27 | * happens for example when trying to use memcpy() from an odd NOR |
| 28 | * flash address; the behaviour can be also seen when using "md" on an |
| 29 | * odd NOR flash address (but there it is not a bug in U-Boot, which |
| 30 | * only shows the behaviour of this processor). |
| 31 | * |
| 32 | * For memcpy(), we test if either the source or the target address |
| 33 | * are not 32 bit aligned, and - if so - if the source address is in |
| 34 | * NOR flash: in this case we perform a byte-wise (slow) then; for |
| 35 | * aligned operations of non-flash areas we use the optimized (fast) |
| 36 | * real __memcpy(). This way we minimize the performance impact of |
| 37 | * this workaround. |
| 38 | * |
| 39 | */ |
| 40 | |
| 41 | #include <common.h> |
| 42 | #include <flash.h> |
| 43 | #include <linux/types.h> |
| 44 | |
| 45 | void *memcpy(void *trg, const void *src, size_t len) |
| 46 | { |
| 47 | extern void* __memcpy(void *, const void *, size_t); |
| 48 | char *s = (char *)src; |
| 49 | char *t = (char *)trg; |
| 50 | void *dest = (void *)src; |
| 51 | |
| 52 | /* |
| 53 | * Check is source address is in flash: |
| 54 | * If not, we use the fast assembler code |
| 55 | */ |
| 56 | if (((((unsigned long)s & 3) == 0) /* source aligned */ |
| 57 | && /* AND */ |
| 58 | (((unsigned long)t & 3) == 0)) /* target aligned, */ |
| 59 | || /* or */ |
| 60 | (addr2info((ulong)s) == NULL)) { /* source not in flash */ |
| 61 | return __memcpy(trg, src, len); |
| 62 | } |
| 63 | |
| 64 | /* |
| 65 | * Copying from flash, perform byte by byte copy. |
| 66 | */ |
| 67 | while (len-- > 0) |
| 68 | *t++ = *s++; |
| 69 | |
| 70 | return dest; |
| 71 | } |