Changeset ac48fef in mainline

Timestamp:

2008-12-27T11:28:06Z (15 years ago)

Author:

Jiri Svoboda <jirik.svoboda@…>

Branches:

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

Children:

9a63657

Parents:

b755225

Message:

Add memmove() function to kernel.

Location:

kernel/generic

Files:

• include/memstr.h (modified) (1 diff)
• src/lib/memstr.c (modified) (2 diffs)

kernel/generic/include/memstr.h

@@ -45 +45 @@
 extern void _memsetb(void *dst, size_t cnt, uint8_t x);
 extern void _memsetw(void *dst, size_t cnt, uint16_t x);
+extern void *memmove(void *dst, const void *src, size_t cnt);
+
 extern char *strcpy(char *dest, const char *src);
 

kernel/generic/src/lib/memstr.c

@@ -1 +1 @@
 /*
  * Copyright (c) 2001-2004 Jakub Jermar
+ * Copyright (c) 2008 Jiri Svoboda
  * All rights reserved.
  *
@@ -77 +78 @@
 }
 
+/** Move memory block with possible overlapping.
+ *
+ * Copy cnt bytes from src address to dst address. The source and destination
+ * memory areas may overlap.
+ *
+ * @param src           Source address to copy from.
+ * @param dst           Destination address to copy to.
+ * @param cnt           Number of bytes to copy.
+ *
+ * @return              Destination address.
+ */
+void *memmove(void *dst, const void *src, size_t n)
+{
+        const uint8_t *sp;
+        uint8_t *dp;
+
+        /* Nothing to do? */
+        if (src == dst)
+                return dst;
+
+        /* Non-overlapping? */
+        if (dst >= src + n || src >= dst + n) { 
+                return memcpy(dst, src, n);
+        }
+
+        /* Which direction? */
+        if (src > dst) {
+                /* Forwards. */
+                sp = src;
+                dp = dst;
+
+                while (n-- != 0)
+                        *dp++ = *sp++;
+        } else {
+                /* Backwards. */
+                sp = src + (n - 1);
+                dp = dst + (n - 1);
+
+                while (n-- != 0)
+                        *dp-- = *sp--;
+        }
+
+        return dst;
+}
+
 /** Fill block of memory
  *