2 files changed, 76 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc5xxx/Makefile b/arch/powerpc/cpu/mpc5xxx/Makefile
index 0ee0611550..4ab2b7be76 100644
--- a/arch/powerpc/cpu/mpc5xxx/Makefile
+++ b/arch/powerpc/cpu/mpc5xxx/Makefile
@@ -30,6 +30,11 @@ SOBJS	= io.o firmware_sc_task_bestcomm.impl.o
 COBJS	= i2c.o traps.o cpu.o cpu_init.o ide.o interrupts.o \
 	  loadtask.o pci_mpc5200.o serial.o speed.o usb_ohci.o usb.o
 
+# Workaround for local bus unaligned access problem on MPC5200
+#ifdef CONFIG_MPC5200
+COBJS	+= memcpy_mpc5200.o
+#endif
+
 SRCS	:= $(START:.o=.S) $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
 START	:= $(addprefix $(obj),$(START))
diff --git a/arch/powerpc/cpu/mpc5xxx/memcpy_mpc5200.c b/arch/powerpc/cpu/mpc5xxx/memcpy_mpc5200.c
new file mode 100644
index 0000000000..09503548aa
--- /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;
+}