Index: uspace/lib/c/include/adt/checksum.h
===================================================================
--- uspace/lib/c/include/adt/checksum.h	(revision ba4a03a5128c12a813b86aec7796e57c21dffead)
+++ uspace/lib/c/include/adt/checksum.h	(revision ba4a03a5128c12a813b86aec7796e57c21dffead)
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2012 Dominik Taborsky
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libc
+ * @{
+ */
+/** @file
+ */
+
+#ifndef LIBC_CHECKSUM_H_
+#define LIBC_CHECKSUM_H_
+
+#include <sys/types.h>
+
+extern uint32_t compute_crc32(uint8_t *, size_t);
+extern uint32_t compute_crc32_seed(uint8_t *, size_t, uint32_t);
+
+#endif
+
+/** @}
+ */
Index: uspace/lib/c/include/adt/list.h
===================================================================
--- uspace/lib/c/include/adt/list.h	(revision 639db552365ea659a19f3cb73b5fb680bc969de0)
+++ uspace/lib/c/include/adt/list.h	(revision ba4a03a5128c12a813b86aec7796e57c21dffead)
@@ -38,4 +38,5 @@
 
 #include <assert.h>
+#include <stdbool.h>
 #include <unistd.h>
 
@@ -72,4 +73,10 @@
 	    iterator = list_get_instance(_link, itype, member), \
 	    _link != &(list).head; _link = _link->next)
+
+#define list_foreach_rev(list, member, itype, iterator) \
+	for (itype *iterator = NULL; iterator == NULL; iterator = (itype *) 1) \
+	    for (link_t *_link = (list).head.prev; \
+	    iterator = list_get_instance(_link, itype, member), \
+	    _link != &(list).head; _link = _link->prev)
 
 /** Unlike list_foreach(), allows removing items while traversing a list.
@@ -105,5 +112,5 @@
 
 #define assert_link_not_used(link) \
-	assert(((link)->prev == NULL) && ((link)->next == NULL))
+	assert(!link_used(link))
 
 /** Returns true if the link is definitely part of a list. False if not sure. */
@@ -357,4 +364,18 @@
 }
 
+/** Determine if link is used.
+ *
+ * @param link Link
+ * @return @c true if link is used, @c false if not.
+ */
+static inline bool link_used(link_t *link)
+{
+	if (link->prev == NULL && link->next == NULL)
+		return false;
+
+	assert(link->prev != NULL && link->next != NULL);
+	return true;
+}
+
 extern int list_member(const link_t *, const list_t *);
 extern void list_concat(list_t *, list_t *);