diff options
Diffstat (limited to 'arch/powerpc/cpu/mpc5xxx/memcpy_mpc5200.c')
-rw-r--r-- | arch/powerpc/cpu/mpc5xxx/memcpy_mpc5200.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc5xxx/memcpy_mpc5200.c b/arch/powerpc/cpu/mpc5xxx/memcpy_mpc5200.c new file mode 100644 index 0000000..0950354 --- /dev/null +++ b/arch/powerpc/cpu/mpc5xxx/memcpy_mpc5200.c @@ -0,0 +1,71 @@ +/* + * (C) Copyright 2010 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +/* + * This is a workaround for issues on the MPC5200, where unaligned + * 32-bit-accesses to the local bus will deliver corrupted data. This + * happens for example when trying to use memcpy() from an odd NOR + * flash address; the behaviour can be also seen when using "md" on an + * odd NOR flash address (but there it is not a bug in U-Boot, which + * only shows the behaviour of this processor). + * + * For memcpy(), we test if either the source or the target address + * are not 32 bit aligned, and - if so - if the source address is in + * NOR flash: in this case we perform a byte-wise (slow) then; for + * aligned operations of non-flash areas we use the optimized (fast) + * real __memcpy(). This way we minimize the performance impact of + * this workaround. + * + */ + +#include <common.h> +#include <flash.h> +#include <linux/types.h> + +void *memcpy(void *trg, const void *src, size_t len) +{ + extern void* __memcpy(void *, const void *, size_t); + char *s = (char *)src; + char *t = (char *)trg; + void *dest = (void *)src; + + /* + * Check is source address is in flash: + * If not, we use the fast assembler code + */ + if (((((unsigned long)s & 3) == 0) /* source aligned */ + && /* AND */ + (((unsigned long)t & 3) == 0)) /* target aligned, */ + || /* or */ + (addr2info((ulong)s) == NULL)) { /* source not in flash */ + return __memcpy(trg, src, len); + } + + /* + * Copying from flash, perform byte by byte copy. + */ + while (len-- > 0) + *t++ = *s++; + + return dest; +} |