+int alloc_ppage(void);
+void free_ppage(int pg);
+
+/* allocate a number of consecutive pages */
+int alloc_ppages(int count);
+void free_ppages(int pg0, int count);
+
+/* allocate a specific range of pages.
+ * Fails (and returns -1) if any page in the requested range is not free.
+ */
+int alloc_ppage_range(int start, int size);
+int free_ppage_range(int start, int size);
+