Changeset b31f735 in mainline

Timestamp:

2012-03-29T21:41:07Z (13 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

bb1b44e

Parents:

9bdf1f2a

Message:

Add memmove() to boot.

Location:

boot/generic

Files:

• include/memstr.h (modified) (1 diff)
• src/memstr.c (modified) (1 diff)

boot/generic/include/memstr.h

@@ -36 +36 @@
 
 extern void *memcpy(void *, const void *, size_t);
+extern void *memmove(void *, const void *, size_t);
 
 #endif

boot/generic/src/memstr.c

@@ -51 +51 @@
 }
 
+/** Move memory block with possible overlapping.
+ *
+ * Copy cnt bytes from src address to dst address. The source
+ * and destination memory areas may overlap.
+ *
+ * @param dst Destination address to copy to.
+ * @param src Source address to copy from.
+ * @param cnt Number of bytes to copy.
+ *
+ * @return Destination address.
+ *
+ */
+void *memmove(void *dst, const void *src, size_t cnt)
+{
+        /* Nothing to do? */
+        if (src == dst)
+                return dst;
+        
+        /* Non-overlapping? */
+        if ((dst >= src + cnt) || (src >= dst + cnt))
+                return memcpy(dst, src, cnt);
+        
+        uint8_t *dp;
+        const uint8_t *sp;
+        
+        /* Which direction? */
+        if (src > dst) {
+                /* Forwards. */
+                dp = dst;
+                sp = src;
+                
+                while (cnt-- != 0)
+                        *dp++ = *sp++;
+        } else {
+                /* Backwards. */
+                dp = dst + (cnt - 1);
+                sp = src + (cnt - 1);
+                
+                while (cnt-- != 0)
+                        *dp-- = *sp--;
+        }
+        
+        return dst;
+}
+
 /** @}
  */