Add simple page allocator and doubly-linked list implementation.

include/list.h

@@ -0,0 +1,40 @@
+#ifndef LIST_H
+#define LIST_H
+
+/*
+ * Assuming ptr is a pointer to a member variable of type parent_type, and ptr
+ * is named member in parent_type, find the address of the struct which owns
+ * ptr.
+ */
+#define container(ptr, parent_type, member) \
+	((parent_type *) ((char *)ptr - (char *)&((parent_type *)0)->member))
+
+/*
+ * Given a pointer to a struct (head) of type dlist_node, which points to a
+ * list of type parent_type, and a pointer of that type (it), this macro will
+ * execute the contained instructions once for each list element, with 'it' set
+ * to each element in the list, in turn.
+ */
+#define for_each_list(it, head, parent_type, member) \
+	for (it = container((head)->next, parent_type, member); it->member.next != (head); it = container(it->member.next, parent_type, member))
+
+#define for_each_list_noinit(it, head, parent_type, member) \
+	for (; it->member.next != (head); it = container(it->member.next, parent_type, member))
+
+struct dlist_node {
+	struct dlist_node *next, *prev;
+};
+
+void init_list(struct dlist_node *n);
+int list_empty(struct dlist_node *n);
+
+//functions for dealing with single list elements
+void insert_after(struct dlist_node *n, struct dlist_node *to_add);
+void insert_before(struct dlist_node *n, struct dlist_node *to_add);
+void remove(struct dlist_node *to_remove);
+
+//functions for dealing with one or more elements
+void remove_splice(struct dlist_node *from, struct dlist_node *to);
+void insert_splice_before(struct dlist_node *n, struct dlist_node *first, struct dlist_node *last);
+
+#endif /* LIST_H */

include/mm.h

@@ -0,0 +1,20 @@
+#ifndef MM_H
+#define MM_H
+
+#include <list.h>
+
+#define MM_PAGE_SIZE 4096
+
+struct page {
+	void *address;
+	struct dlist_node list;
+	char free;
+};
+
+void mm_init();
+void mm_add_free_region(void *start, void *end);
+
+struct page* mm_get_free_pages(unsigned int power);
+int mm_put_free_pages(struct page *p);
+
+#endif /* MM_H */