Index: uspace/lib/posix/strings.c
===================================================================
--- uspace/lib/posix/strings.c	(revision 0c16ab1e8c7c86d6b4cc51130ce7632194312285)
+++ uspace/lib/posix/strings.c	(revision fc3680e2adf3ddc38c91e5a91a5dc4290965bf91)
@@ -31,5 +31,5 @@
  * @{
  */
-/** @file
+/** @file Additional string manipulation.
  */
 
@@ -45,7 +45,8 @@
 
 /**
+ * Find first set bit (beginning with the least significant bit).
  *
- * @param i
- * @return
+ * @param i Integer in which to look for the first set bit.
+ * @return Index of first set bit. Bits are numbered starting at one.
  */
 int posix_ffs(int i)
@@ -82,8 +83,10 @@
 
 /**
+ * Compare two strings (case-insensitive).
  *
- * @param s1
- * @param s2
- * @return
+ * @param s1 First string to be compared.
+ * @param s2 Second string to be compared.
+ * @return Difference of the first pair of inequal characters,
+ *     or 0 if strings have the same content.
  */
 int posix_strcasecmp(const char *s1, const char *s2)
@@ -93,9 +96,11 @@
 
 /**
+ * Compare part of two strings (case-insensitive).
  *
- * @param s1
- * @param s2
- * @param n
- * @return
+ * @param s1 First string to be compared.
+ * @param s2 Second string to be compared.
+ * @param n Maximum number of characters to be compared.
+ * @return Difference of the first pair of inequal characters,
+ *     or 0 if strings have the same content.
  */
 int posix_strncasecmp(const char *s1, const char *s2, size_t n)
@@ -116,9 +121,11 @@
 
 /**
+ * Compare two memory areas.
  *
- * @param mem1
- * @param mem2
- * @param n
- * @return
+ * @param mem1 Pointer to the first area to compare.
+ * @param mem2 Pointer to the second area to compare.
+ * @param n Common size of both areas.
+ * @return If n is 0, return zero. If the areas match, return
+ *     zero. Otherwise return non-zero.
  */
 int posix_bcmp(const void *mem1, const void *mem2, size_t n)
@@ -128,19 +135,21 @@
 
 /**
+ * Copy bytes in memory with overlapping areas.
  *
- * @param dest
- * @param src
- * @param n
+ * @param src Source area.
+ * @param dest Destination area.
+ * @param n Number of bytes to copy.
  */
-void posix_bcopy(const void *dest, void *src, size_t n)
+void posix_bcopy(const void *src, void *dest, size_t n)
 {
 	/* Note that memmove has different order of arguments. */
-	memmove(src, dest, n);
+	memmove(dest, src, n);
 }
 
 /**
+ * Reset bytes in memory area to zero.
  *
- * @param mem
- * @param n
+ * @param mem Memory area to be zeroed.
+ * @param n Number of bytes to reset.
  */
 void posix_bzero(void *mem, size_t n)
@@ -150,8 +159,10 @@
 
 /**
+ * Scan string for a first occurence of a character.
  *
- * @param s
- * @param c
- * @return
+ * @param s String in which to look for the character.
+ * @param c Character to look for.
+ * @return Pointer to the specified character on success,
+ *     NULL pointer otherwise.
  */
 char *posix_index(const char *s, int c)
@@ -161,8 +172,10 @@
 
 /**
- * 
- * @param s
- * @param c
- * @return
+ * Scan string for a last occurence of a character.
+ *
+ * @param s String in which to look for the character.
+ * @param c Character to look for.
+ * @return Pointer to the specified character on success,
+ *     NULL pointer otherwise.
  */
 char *posix_rindex(const char *s, int c)
Index: uspace/lib/posix/strings.h
===================================================================
--- uspace/lib/posix/strings.h	(revision 0c16ab1e8c7c86d6b4cc51130ce7632194312285)
+++ uspace/lib/posix/strings.h	(revision fc3680e2adf3ddc38c91e5a91a5dc4290965bf91)
@@ -31,5 +31,5 @@
  * @{
  */
-/** @file
+/** @file Additional string manipulation.
  */
 
@@ -37,6 +37,6 @@
 #define POSIX_STRINGS_H_
 
+/* Search Functions */
 #ifndef POSIX_STRING_H_
-/* Search Functions */
 extern int posix_ffs(int i);
 #endif
@@ -56,5 +56,5 @@
 /* Legacy Functions */
 extern int posix_bcmp(const void *mem1, const void *mem2, size_t n);
-extern void posix_bcopy(const void *dest, void *src, size_t n);
+extern void posix_bcopy(const void *src, void *dest, size_t n);
 extern void posix_bzero(void *mem, size_t n);
 extern char *posix_index(const char *s, int c);